High surface area and interconnected nanoporosity of clay-rich astromaterials

High surface area and interconnected nanoporosity of clay-rich astromaterials | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article High surface area and interconnected nanoporosity of clay-rich astromaterials Laurence A.J. Garvie, László Trif, Desireé Cotto-Figueroa, Erik Asphaug, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3854166/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 May, 2024 Read the published version in Scientific Reports → Version 1 posted 8 You are reading this latest preprint version Abstract Several important processes, from meteor disruption in Earth’s atmosphere and impact with the ground, to the comminution of boulders by thermal and impact processes and slope mechanics on the surface of an asteroid, to access and utilization of in-situ resources, depend on astromaterial properties including porosity, sound speed, thermal conductivity, and compressive strength. Whereas the bulk porosity of clay-rich meteorites is well established, the magnitude of their surface area and nano-scale porosity is poorly known. Here we apply the N 2 BET gas adsorption method to measure the scale-distribution and net surface area of porosity in a range of clay-rich meteorites. Tarda (C2-ung) has high surface area, up to 82 m 2 /g, dominated by an interconnected network of ~ 3-nm-sized pores. In comparison, Ivuna and Orgueil (CI1) and Aguas Zarcas and Murchison (CM2) have bimodal nanopore-size distributions with a lower density of ~ 3-nm pores and broader size distributions around 40 nm, and corresponding lower surface areas ~ 14–19 m 2 /g. The high-surface-area of Tarda may indicate a high density of intra-tachoid pores among and between the nano-sized aggregates of poorly ordered clays. Samples from asteroids Ryugu and Bennu, mineralogically and texturally similar to Tarda, may have similarly interconnected nano-scale porosity with high surface area. Earth and environmental sciences/Planetary science Physical sciences/Astronomy and planetary science Physical sciences/Materials science Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Clay-rich rocks have complex pore structures controlled by the microstructure and aggregation of the clays. Their multiscale clay-aggregate structure can give rise to high surface areas dominated by nanometer-scale porosity with different dimensions and scales 1 , 2 . This porosity, pore-size distribution, and pore connectivities are important properties in clay-rich rocks that affects their strength, thermal conductivity, speed, and attenuation of sound, and transport of fluids. Although there has been significant research on the bulk porosity of meteorites 3 – 6 , the bulk submicron-scale porosity in CCs is relatively understudied. This submicron porosity, and in particular bulk fine-scale porosity and pore-size distribution can be probed through a range of techniques including X-ray tomography, transmission electron microscopy, NMR cryoporometry, and inert gas adsorption 7 – 11 . Of these methods, physical adsorption of an inert gas, such as nitrogen is widely used to probe the surface area and bulk fine-scale porosity and pore-size distribution 11 . Nitrogen gas adsorption can reveal information on the total surface area and nanometer-scale pore characteristics for pores < 200 nm in diameter. Insights into the adsorption process is provided by application of the Brunauer-Emmett-Teller (BET) theory 11 – 14 . Pore sizes accessible to N 2 BET are divided into micropores ( 50 nm) 14 . The BET and the Barrett, Joyner, and Halenda (BJH) method has been applied to create pore volume and surface area distributions based on adsorption-desorption isotherms for a wide range of terrestrial clays and shales 1 , 15 – 18 . Despite extensive research on terrestrial clays and argillaceous rocks, only limited BET gas adsorption research has been conducted on clay-rich meteorites 19 – 21 . Consequently, the surface area and nanopore-size distribution in these meteorites, and by extension their parent asteroids remains poorly understood. The current motivation to study C-type astromaterials free of terrestrial contamination propelled return missions to two Near Earth Objects (NEOs) − 162173 Ryugu and 101955 Bennu. Bennu was chosen as the target of OSIRIS-REx 22 in part due to its spectral similarities to primitive, organic-rich CCs and for its potential to impact Earth between the years 2175 and 2199 23 . On 20th October 2020, OSIRIS-REx touched down on Bennu and returned ~ 100 g on the 24th of September 2023. The Hayabusa2 mission returned samples from the potentially hazardous asteroid Ryugu. The Ryugu and Bennu samples show close mineralogical similarities with the CI1 CCs 24 , 25 , establishing a direct relationship between meteorites and their parent asteroids. Many petrologic types 1 and 2 CCs, including the samples returned from asteroids Ryugu and Bennu, are dominated by phyllosilicates 26 – 32 . The bulk powder low-angle X-ray diffraction (XRD) patterns show that their clays are broadly divided into serpentines and smectites or a combination thereof 27 , 33 – 35 . Clay-rich rocks can have complex pore structures controlled by the microstructure and aggregation of the clays. A multiscale clay aggregate structure gives rise to porosity with different dimensions and scales 1 , 2 . This porosity, pore-size distribution, and pore connectivities are important properties in clay-rich rocks as they affect key properties of the astromaterial including strength, thermal conductivity, speed, and attenuation of sound 5 , and on transport of fluids on the early parent body that gives rise to the complex, multiscale mineralogies, e.g., 36 , 37 . In this study, we explore the surface area, fine-scale porosity, and pore-size distribution in clay-rich CC meteorites with the N 2 BET gas adsorption method and apply the BJH analysis to create pore volume and surface area distributions based on the adsorption-desorption isotherms. Our primary focused is on the recent Tarda (C2-ung) fall. For comparison, BET data is also acquired from four well-studied clay-rich CC falls, Ivuna (CI1), Orgueil (CI1), Aguas Zarcas (CM2), and Murchison (CM2), and an anhydrous CC, Allende (CV3). A major finding of our study is that Tarda has high surface area, up to 82 m 2 /g, and a pore-size distribution, obtained by applying the BJH method from the adsorption isotherm, with a maximum near the upper boundary with the micropore range and a broad tail into the macropore region. In contrast, the other clay-rich meteorites have lower surface areas (13.8 to 18.6 m 2 /g), and bimodal pore-size distributions with less-pronounced maximum near 3-nm peak and broader more intense distribution that straddles the meso- macropore boundary. The Tarda data advocates for a high density of intra-tachoid pores, in, around and between the nano-sized aggregates of poorly ordered clays. It is speculated that the recently returned asteroid samples from Ryugu and Bennu, which show mineralogical similarities to Tarda, will also show a similarly high surface area and fine-scale, interconnected nanoporosity. Results and discussion Nitrogen adsorption and surface area measurements. Prior to entering the Earth atmosphere, meteorites and asteroid returned samples inhabit the ultrahigh vacuum of space, with a pressure near 1.3 x 10 − 11 Pa, equivalent to at most a few tens of atoms/cm 3 . However, once on Earth, they immediately adsorb our atmosphere which exposes their surface area to atmospheric gases. Therefore, prior to the N 2 BET measurements, it is necessary to remove these physisorbed species through outgassing 11 . In this paper, the outgassing pretreatment is listed after the meteorite name: Tarda-100 refers to the sample outgassed at 100°C under flowing N 2 for 24 hr; after prolonged storage under a dry N 2 atmosphere (-NH); after being held under a vacuum for 24 hr at room temperature (-VRT); and, after heating in the presence of flowing dry nitrogen at 250°C for 24 hr (-250) (Table 1 ). The N 2 BET measurements are made by exposing the degassed sample to N 2 at a series of controlled pressures while maintaining the sample at a constant cryogenic temperature of -195.8°C, which corresponds to the boiling point of N 2 . The volume of adsorbed or desorbed gas is measured over a relative equilibrium adsorption pressure (p/p 0 ) from near 0 to 1, where p is the absolute equilibrium pressure and p 0 the saturation pressure of the gas 1 , 11 . The plot of p/p 0 versus the quantity of gas adsorbed is called the adsorption isotherm. Prior to the N 2 BET analyses, all samples were checked first by powder X-ray diffraction (See Supplementary Data, Figs. S1, S2, and details in the Experimental section). Table 1 Meteorites studied, degas conditions, BET surface area (S BET ), BET C parameter (C), monolayer capacity - n m , BJH adsorption cumulative volume of pores (V ad ), BJH desorption cumulative volume of pores (V ds ), and pore size for selected meteorites determined from the N 2 adsorption isotherms at 77 K. Meteorite Degas Condition C n m (cm 2 /g) S BET (m 2 /g) V ad (cm 3 /g) 1 V ds (cm 3 /g) 2 Pore size 3 nm Tarda 250 189.3 18.7499 81.61 ± 0.26 0.0907 0.0999 4.71 Tarda 100 124.3 16.0960 70.06 ± 0.14 0.0821 0.0894 4.91 Tarda p 100 104.2 14.9255 64.97 ± 0.38 0.0757 0.0967 5.96 Tarda g 100 99.5 11.0047 47.90 ± 0.08 0.0634 0.0683 5.36 Tarda VRT 98.6 15.1008 49.34 ± 0.14 0.0671 0.0719 5.29 Tarda NH 59.5 7.7325 33.67 ± 0.25 0.0531 0.0507 5.64 Ivuna 100 106.6 4.2185 18.36 ± 0.10 0.0828 0.0840 15.56 Orgueil 100 95.5 3.4934 15.21 ± 0.09 0.0643 0.0652 15.11 Aguas Zarcas 100 134.1 3.7734 16.42 ± 0.06 0.0588 0.0613 14.40 Aguas Zarcas NH 131.4 2.3602 10.27 ± 0.07 0.0407 0.0263 15.10 Murchison 100 99.4 3.1727 13.81 ± 0.08 0.0524 0.0545 14.58 Allende 100 64.9 0.2775 1.21 ± 0.01 0.0074 0.0082 29.0 p – powder, g – exposed to 100% RH at 32°C for 24 hours forming gypsum, and then degassed under flowing N 2 at 100°C. NH – sample not outgassed at 100°C for 24 hr. VRT – outgassed at room temperature under vacuum for 24 hr. 100 – outgassed under flowing dry N 2 at 100°C for 24 hr. 250 – outgassed under flowing dry N 2 at 250°C for 24 hr. 1 - BJH Adsorption cumulative volume of pores between 1.7 nm and 300.0 nm width. 2 - BJH Desorption cumulative volume of pores between 1.7 nm and 300.0 nm width. 3 - BJH Adsorption average pore width (4V/A). The Tarda adsorption isotherms show six distinct regions (Fig. 1 a) – a near vertical rise in adsorption for p/p 0 < 0.02 (Fig. S3), a broad kink in the adsorption volume up to p/p 0 ~ 0.05, an almost linear increase in p/p 0 to ~ 0.35, slightly non-linear positive adsorption to p/p 0 ~ 0.9, after which there is a slight flattening for p/p 0 between 0.9 and 0.95, followed by an asymptotic increase in adsorption at p/p 0 = 1 (Fig. 1 a). Comparison of these isotherms with the Brunauer-Deming-Deming-Teller (BDDT) physisorption isotherm types 11 , 14 shows that Tarda possesses a hybrid adsorption isotherm with a Type 1b onset followed by a Type II isotherm with a hint of Type IV character at high p/p 0 . A Type Ib onset is interpreted as the filling of micropores with a range of pore volumes that extends into the mesopore region. The steep, almost linear increase in adsorption above p/p 0 ~ 0.05, suggests a broad range of mesopore volumes. The final asymptotic increase at p/p 0 = 1 can be attributed to incomplete filling of macropores, i.e., those > 200 nm in diameter that are too large to be filled as p/p 0 approaches 1. In general, the degree of N 2 uptake for p/p 0 ~ 1 is proportional to the total porosity of pores to ~ 200 nm in diameter showing that outgassing significantly increases the total micro and mesoporosity. While the Tarda adsorption isotherms do not have a plateau at high p/p 0 , as is expected for a Type IV isotherm, the slight flattening for p/p 0 between 0.9 and 0.95 suggest complete filling of the mesopores up to ~ 200 nm, but a lower density of large macropores remain unfilled at p/p 0 = 1. Tarda shows pronounced hysteresis during desorption (Fig. 1 b, S4), dominated by an H2 hysteresis loop pattern, though the onset of the desorption for p/p 0 > 0.95 shows H3 character 11 . The desorption isotherm does not track with the adsorption path and shows a marked hysteresis at p/p 0 ~ 0.35–0.45. The steepness of the desorption branch for p/p 0 < 0.5 informs on pore-size range, pore geometry and connectivity (see below). The adsorption profiles for the smectite-rich Orgueil and Ivuna and serpentine-rich Aguas Zarcas and Murchison, all outgassed at 100°C, show similar adsorption profiles (Figs. 1 c,d, S5,6) matching a Type II isotherm. There is a small but rapid increase in adsorbed N 2 for p/p 0 < 0.02, gradual uptake up to p/p 0 ~ 0.8, and then rapid uptake to p/p 0 = 1. Aguas Zarcas and Murchison show an H3 type desorption isotherm with rapid decrease in the desorption isotherm at 0.4 < p/p 0 < 0.5 (Fig. 1 d, S6). The hysteresis loop of the desorption branch for Ivuna and Orgueil are more complex. Desorption of Orgueil is linear for 0.5 < p/p 0 < 1 with a sharp and sudden decrease from p/p 0 of 0.5 to 0.45 (Fig. S5). Ivuna shows linear desorption 0.85 < p/p 0 < 1, and H2b like hysteresis in the range 0.5 < p/p 0 < 0.85, and rapid decrease in the quantity adsorbed and closure of desorption isotherm at 0.4 < p/p 0 < 0.5 (Fig. 1 c). In contrast, Allende is largely dominated by anhydrous silicate, FeS, and metal shows a Type II adsorption isotherm and a desorption isotherm that largely tracks the adsorption pathway (Fig. S7). Insights into the surface area of porous materials can be gained by application of the Brunauer-Emmet-Teller (BET) equation $$\frac{1}{\varvec{n}(\frac{{p}^{0}}{p}-1)}=\frac{C-1}{{\varvec{n}}_{m}C}\left(\frac{p}{{p}^{0}}\right)+\frac{1}{{\varvec{n}}_{m}C}$$ to the isotherms, where n is the specific amount adsorbed in cm 3 /g at STP at relative pressure p/p 0 and n m is the specific monolayer capacity 11 , 14 . The specific monolayer capacity n m is determined by plotting the BET function 1/( n (p 0 /p-1) against the relative adsorption pressure p/p 0 , called the BET plot 11 , within the linear range of p/p 0 , which is typically ∼0.05–0.30 for Type II and Type IVa isotherms 11 . The slope of the linear regression of the linear range of the BET plot is used to derive n m =1/( s + i ), where s is the slope and i the intercept, and C = s / i + 1. The suitability of this linear BET plot is demonstrated for Tarda-100, which shows that p/p 0 from 0.30074 to 0.056479 lie along a straight line with R 2 = 0.99993 (Fig. S8) and is the region of the isotherm in which statistically the volume adsorbed corresponds to just the complete monolayer. Above and below these p/p 0 values the points deviate from the linear regression and are not used for the BET surface area calculation (Fig. S8). The BET surface area is calculated using, $${S}_{BET} =\frac{{\varvec{n}}_{m} \text{L} {\sigma }_{m}}{{V}_{0} m}$$ where S BET is the BET specific area, n m the monolayer capacity, σ m is the molecular cross-sectional area occupied by the adsorbate molecule which for N 2 is 16.2 x 10 − 20 m 2 (0.162 nm 2 ), L is the Avogadro constant 6.022 x 10 23 , V 0 is the molar gas volume of the adsorptive at STP, and m is the mass of the sample. Using this analysis, the BET specific surface areas for the clay-rich meteorites range from 10.27 to 81.61 m 2 /g and only 1.21 m 2 /g for the anhydrous Allende (Table 1 ). Different degassing pretreatments have significant effects on the BET surface area with the Tarda values ranging from 33.67 m 2 /g for the sample taken directly from the nitrogen cabinet to 81.61 m 2 /g after the 250°C treatment. Powdering has little effect on the surface area measurement, i.e., compare Tarda-100 and Tarda p -100 (Table 1 ). Despite the differing hysteresis patterns between the smectite-rich Orgueil and Ivuna and the serpentine-rich Aguas Zarcas and Murchison, their S BET values are close (Table 1 ), though the profile differences provide information on pore-size distribution, pore geometry and network effects. The S BET values of the clay-rich meteorites measured here are within the range of terrestrial argillaceous rocks and clays 1 , 15 – 18 , 38 . For example, S BET for The Clay Minerals Society source clays measured by BET N 2 gas adsorption ranged from 12.1 to 173 m 2 /g 15 , though the three natural smectites had values 22.7 to 65.2 m 2 /g. The S BET values for Orgueil and Ivuna are significantly less than the mineralogically similar Tarda despite the similar bulk mineralogy. The value measured here for Orgueil-100 of 15.21 m 2 /g is half that previously reported 20 , despite the similar degassing conditions. This difference may be the result of the varied curatorial histories of samples since its fall in 1864, however, the value measured here is still within the range for smectite-rich argillaceous rocks. In addition, the S BET data for Tarda acquired after different pretreatment and outgassing treatments varies by over a factor x2 for the sample run directly from the dry N 2 chamber to the one outgassed at 250°C under flowing N 2 . It is also likely the S BET values would be even higher under vacuum degassing, which would more closely replicate conditions in space. Information on the pore-size distribution and average pore size is gained using the isotherm data by employing the t-Plot method using a Harkins and Jura thickness equation and BJH analyses with Halsey-Faas correction to derive the pore data. The single-point cumulative volume of pores in the 1.7 nm and 300.0 nm width range (V ad ) calculated from the adsorption data for the clay-rich meteorites ranges from 0.0524 to 0.0907 cm 3 /g (Table 1 ). The same calculated from the desorption data (V ds ) are of a similar magnitude, though in general a few percent larger (Table 1 ). Despite Tarda-100 having a significantly higher S BET than Ivuna, their V ad values are close. In general, V ad for the serpentine-rich Aguas Zarcas and Murchison are lower than the smectite-rich meteorites, with the anhydrous Allende showing the lowest V ad value. However, there are significant differences in their < 200 nm pore-size distributions derived from the N 2 BET data with the Halsey Faas correction calculated from the adsorption isotherms. A commonly used method to display the pore-size distribution is through the plot of the logarithmic differential pore-volume distribution, dV/d (log(w)), versus pore width 1 , 11 . Here, the area under the curve in any pore diameter range yields the volume of pores in that range. These plots derived for the adsorption branch of the isotherms show that Tarda has significant mesoporosity, with a maximum near the upper boundary with the micropore range and a broad tail into the macropore region (Fig. 2 a). The profile maximum becomes narrower and more intense from Tarda NH → VRT → 100 → 250. In contrast, the mineralogically similar Orgueil and Ivuna have a bimodal pore-size distribution with a major maximum near 40 nm and a minor peak around 3 nm (Fig. 2 b and S9). The profiles for Aguas Zarcas and Murchison show a less-pronounced 3-nm peak and broader maximum that straddles the meso- macropore boundary (Fig. 2 b and S10). The anhydrous Allende lacks significant microporosity and has a broad maximum near 100 nm (Fig. 2 b). While the application of Kelvin equation-based procedures, such as the BJH method, can with some pore geometries underestimate the pore size, e.g., 8 , the plots of pore width versus the log differential pore size for the meteorites provide a semi-quantitative view of the pore-size distribution. In certain pore geometries the desorption isotherm can provide a more accurate representation of the pore geometry as it is thought that the desorption process is in thermodynamic equilibrium between the liquid adsorbed phase in the pores and the external gaseous phase. However, the smectite and serpentine-rich meteorites studied here all show the sudden abrupt closure of the desorption branch to the adsorption branch of the isotherm near p/p 0 ~ 0.4. The plots of pore width versus the log differential pore size determined from the desorption isotherms of the clay-rich meteorites all show a sharp spike at 3.8 nm (Fig. 2 c,d). This spike is caused by rapid desorption during evaporation from the pore neck and the pore body involving cavitation and the growth of vapor bubbles in the metastable condensed fluid, and is evidence for pore restriction smaller than ~ 5 to 6 nm for N 2 at 77 K 9 , 10 . The peak in the micropore-mesopore boundary region in the pore-size distribution from smectite-rich rocks is attributed to “intra-tachoid” porosity 1 , 39 . Tachoids are 2- to 50-nm sized aggregates with turbostratic stacking of the phyllosilicate TOT plates. Tarda is smectite-rich, and a maximum in the micropore region is consistent with intra-tachoid porosity. However, the rapid decrease in dV/dlog(w) with increase in pore size (Fig. 2 a) suggests a decreasing density of pores in the 50- to 100-nm-size range between the tachoids, whereas Orgueil, Ivuna, Aguas Zarcas, and Murchison possess significant inter-tachoid and intra-aggregate porosity. For example, HRTEM images of Orgueil show a highly disordered submicron mélange of interpenetrating platy, curved, and poorly crystalline phyllosilicates and ferrihydrite together hosting nanometer-sized sulfides 32 , with abundant sites for intra-tachoid porosity. More recently, HRTEM images from Ryugu C1-like material shows similar fine-scale phyllosilicate complexity 24 . In both the Orgueil and Ryugu material the nanoscale tachoid nature of the matrix is evident in the HRTEM images. In contrast, the matrices of the CM2 chondrites show regions of more coarsely crystalline phyllosilicates commonly with platy and polygonal morphologies as well as regions with submicron tissue-like aggregates 40 – 43 . Characterizing the adsorbed water The ease with which the smectite-rich meteorites adsorb and intercalate water from the atmosphere makes the determination of the indigenous molecular water challenging. The quantity of water adsorbed and retained by Tarda under normal laboratory conditions can be measured by thermal gravimetric analysis (TG) combined with mass spectrometric evolved-gas analysis system (MSEGA). MSEGA detects evolved gases that have distinct ion mass to charge ratios (m/z). These methods are used to provide information on the H 2 O and OH − content of the phyllosilicates and other H-bearing in the CC meteorites 20 , 27 , 30 , 44 . The thermal analysis was recently described from Aguas Zarcas 27 and so the focus of the discussion here is on Tarda. Although samples were heated to 1000°C, the primary temperature range of interest here is below 300°C, which is within the range that the samples were heated prior to the N 2 BET analysis and lower than the dehydroxylation temperatures for the phyllosilicates. Two Tarda samples were analyzed. The first is a fresh powder curated under a dry N 2 atmosphere – Tarda N . The second, called Tarda W , was a powder mixed with distilled water and allowed to dry at room temperature under ~ 34% RH. The TG mass losses for Tarda N and Tarda W heated to 1000°C are 16.6 and 19.4%, respectively (Figs. 3 , S11, S12). Their TG, DSC, and MSEGA profiles are broadly similar (Figs. S11-15), though there are significant differences below 200°C (Fig. 3 ). The DTG curves show three prominent features near 100°, 510°, and 760° C, corresponding to the significant rates of change in the TG mass loss curve. The first mass loss step for Tarda N and Tarda W between 60° and 200°C are Δm − 1.011% and − 3.013%, respectively (Figs. 3 a, S11,12). This first mass loss step corresponds to the loss of adsorbed water and water intercalated with the smectite clays. The 100°C peak in the DTG curve corresponds to the endothermic peak in the DSC curve (Fig. S14). The identity of the gas species evolved corresponding to specific regions of the TG loss curve is revealed by the MSEGA data. A wide range of ion species are evolved during heating and most of the ion signals for Tarda N and Tarda W are similar over the 1000°C range (Fig. S15). However, below 300°C there are yield differences for m/z = 18, 30, and 44. The most abundant gas released below 300°C has m/z = 18 corresponding to H 2 O and its signal is significantly more intense for Tarda W . The signal for m/z = 44, corresponding to CO 2 , is more intense for Tarda W with a maximum near 90°C (Fig. 3 d). Below ~ 200°C, there is little evidence from the MSEGA data for evolution of organic compounds. For example, significant signals for m/z = 15 (CH 3 + , methyl derivatives) and 26 (C 2 H 2 + from aromatic hydrocarbons) are absent at this low temperature range (Fig. S15). However, the signal for m/z = 30 shows two maxima below 300°C at 100°C and 200°C for Tarda W , whereas Tarda N only shows a weak maximum at 200°C (Fig. S16). This peak can have several origins, including CH 2 O + and C 2 H 6 + . The mass loss for Tarda W below 200°C of 3.01 wt% is at the lower end for the two published values of 3.7 and 7 wt% 45,46 . This mass-loss range is typical for smectite-rich type 1 meteorites of ~ 5 to ~ 10 wt% 19,20,30,44 . However, samples dried under flowing He for 24 hr show a mass loss of 1.011 wt% (Fig. 3 a, S11), whereas the artificially weathered sample has a mass loss of 3.013 wt % after being dried under laboratory conditions with ~ 35% RH (Fig. 3 a, S12). The data for Tarda suggests that the quantity of molecular water intercalated with the clays prior to arrival on Earth is minor. This result is corroborated by the low mass loss of ~ 0.6 wt% below 200°C for the mineralogically similar samples from asteroid Ryugu 47 . Mineralogical and physical effects of high surface area. The high S BET of the clay-rich meteorites as well as the nanoscale interconnected porosity allows atmospheric water vapor to impinge upon the bulk of the matrix mineral network. In addition, the terrestrial alteration of Tarda and the CI chondrites is accentuated by the ability of their abundant matrix smectite to intercalate water 20 , 48 . While the S BET derived from N 2 BET gives a measure of the N 2 accessible surface area, this gas does not probe the interlayer adsorption sites of the smectite. For example, the surface area of Orgueil measured by the BET using N 2 is 30.2 m 2 /g and 165.8 m 2 /g using H 2 O 20 . Water intercalates around the interlayer cations between stacked 2:1 layers of the smectite clays. The intercalation of water by the smectite group minerals has been extensively studied 38 , 48 – 53 . The degree of intercalation is dependent on the elemental properties of the clay, in particular the type of interlayer cation, and p/p 0 of the surrounding water vapor 48 . Increasing p/p 0 causes interlayer adsorption with a stepwise increase in the d 001 spacing of smectite. For example, the d 001 of Ca montmorillonite increases from 9.6–10.7 Å for the fully dehydrated form, to 11.8–12.9 Å, 14.5–15.8 Å, to 18.0-19.5 Å, for the mono-, bi- and tri-hydrate, respectively 48 , 51 . In contrast, the serpentine 001 reflection from Aguas Zarcas and Murchison is not affected by the water uptake. The smectite d 001 spacing for Tarda shows similar behaviors with respect to p/p 0 , increasing from 10.9 Å at 0% RH to 15.1 Å at 100% RH (Fig. 4 ). However, the extreme breadth of the smectite d 001 spacing strongly suggests material that is on average fine grained, poorly crystalline, with turbostratic stacking, interstratified, or a combination thereof 54 , 55 . This disorder is particularly evident for Tarda heated to 300°C corresponding to the fully dehydrated form and shows an exceptionally broad d 001 basal spacing spread over ~ 5 °2θ Cu K α. In contrast, well crystallized smectite shows a sharp d 001 for the different hydration states, e.g., 51 . The broadness of the Tarda smectite d 001 peak may also arise from materials intercalated between the 2:1 layers, similar to the carbonaceous material intercalated between the smectite 2:1 layers in Orgueil 56 . This intercalated material prevents the 2:1 smectite layers from collapsing and forming a narrow d 001 spacing. Fragments of Tarda swell and crack under high humidity and cycles of higher and lower humidity cause spalling of the fragments (Figs. 5 , S17). This cracking is also accompanied by the growth of gypsum on the fragments within a few days under high relative humidity. Gypsum growth is instituated by the high surface area that forms the interconnected nanoporous sponge-like network of nano-sized pathways. The rapidity of gypsum formation was evident from the powder XRD, which show a prominent gypsum 020 reflection after only 12 hr at 100% RH (Fig. 4 b). The formation of the gypsum is an irreversible mineralogical change that increases the mass of the sample and decreases the surface area. For example, the S BET of the gypsum-rich Tarda (Tarda g ) was significantly lower than Tarda-100 (Table 1 ). Tarda shows an extreme example of terrestrial alteration by rapidly slaking in water (Supplementary Movie1) and other polar liquids. Slaking is a commonly shown by many clay-rich soils 57 . From a practical point of view this slaking is problematic as many laboratory sample preparation techniques, such as cutting, grinding, and polishing use polar liquids, most commonly water, ethylene glycol, alcohols, or acetone as a lubricant. This behavior is not unique to Tarda. For example, in 1834 Berzelius said that in the presence of water the CI1 chondrite Alais “... zerfällt er nach einigen Augenblicken su einem graugrünen Brei ... .” 58 . This extreme reaction to polar liquids has implications for curation as well as sample preparation for analytical studies. The propensity of the smectite-rich meteorites, and to a certain degree those that are serpentine-rich, to disintegrate using polar liquids requires alternative cutting and polishing methods. In particular, cutting and grinding down to 1200 grit size is done dry and without the use of any liquids. Final polishing is achieved with mineral oil and diamond that is then washed with a non-polar solvent, such as toluene. Conclusions The N 2 BET analysis of the clay-rich meteorites reveals scale-dependent aspects of their interiors: their high surface areas, indicative of nano-scale porosity, and the ease with which adsorption sites become blocked by atmospheric gases, including during curation in an N 2 atmosphere. The N 2 accessible high surface areas, formed by the interconnected mesoporosity, constitutes a sponge-like network with nano-sized pathways for water vapor in the atmosphere to impinge upon and intercalate smectite throughout the bulk of the material. The S BET of 81.61 m 2 /g for Tarda-250, although higher than many terrestrial clays, may still be lower than its S BET prior to entering the Earth’s atmosphere, because nano-scale porosity is so rapidly blocked and modified during terrestrial residence. We demonstrated this blocking effect by subjecting Tarda to 100% RH at 32°C for 24 hours. We find that S BET is significantly reduced by blocking, accompanied by the growth of abundant gypsum on and within the fragments. Furthermore, the surface area adsorption capacity of smectite-rich meteorites will be significantly higher than the S BET determined with N 2 BET, as this gas does not probe the interlayer regions around the cations between the 2:1 layers of the clay. From a practical point of view, the rate and ease with which these clay-rich astromaterials adsorb atmospheric gases, but not limited to H 2 O, implores the need for curation in a stable atmosphere with constant low relative humidity to preserve their indigenous physical and chemical properties. The revelation that smectite and serpentine-rich astromaterials possess an intrinsic high-surface area with a nanoporous network also has implications for other physical properties including sound speed, thermal conductivity, and compressive strength which depend on the structural distribution within the material. These astromaterial properties govern, for instance, the resistance of boulders on the surface of an asteroid to hypervelocity impacts and to thermal cycling on their parent body. They also govern how, and how deep, a meteor comes apart during atmospheric entry. The measurement of porosity is probably the easiest way of probing the nano-scale structure of astromaterial, complementary to measurements of crush-curves and other failure mechanisms. The high surface area of Tarda, and the ease with which S BET is reduced by 24-hr duration at high humidity, may explain the significantly lower surface area obtained for the mineralogically-similar meteorites Ivuna and Orgueil. Ivuna and Orgueil have had relatively long residence times on Earth, i.e., 1938 and 1864, respectively, which led to the formation of pore-blocking secondary minerals. In contrast, Tarda fell in southern Morocco on the 25th of August 2020, and the specimens studied here were rapidly collected and since curated under a dry N 2 atmosphere in BCMS. We therefore speculate that the recently returned asteroid samples from Ryugu and Bennu, which have mineralogical and structural similarities to Tarda, will also show a similarly high surface area and fine-scale, interconnected nanoporosity subject to blocking. Experimental section Meteorites and curatorial conditions. All the meteorites studied here are curated under a dry N 2 atmosphere in the Carleton B Moore Meteorite Collection in the Buseck Center for Meteorite Studies (BCMS) at Arizona State University (ASU). The following samples were studied – Tarda (ASU#2149), Ivuna (ASU#856), Orgueil (ASU#222), Aguas Zarcas (ASU#2121), Murchison (ASU#828), and Allende (ASU#818). Aguas Zarcas fell in Costa Rica on the 23 rd of April 2019. Sample were collected and returned to the BCMS by Michael Farmer within one week of the fall and curated under a dry N 2 atmosphere. Tarda fell in southern Morocco on the 25 th of August 2020 and sample were curated under a dry N 2 atmosphere in BCMS by September of 2020. Neither Aguas Zarcas nor the Tarda samples received by BCMS saw significant moisture, other than atmospheric air, before curation under the dry N 2 atmosphere. In addition, selected comparative measurements were undertaken on Murchison (CM2) and Ivuna (CI1). Murchison fell over Murchison, Australia on the 28 th of September 1969 and Ivuna fell near the western shore of Lake Rukwa in Tanzania on 16 th December 1938. Humidity in air near 0% was achieved by placing the samples in a bell jar which contained an open container of the drying agent P 2 O 5 . Laboratory temperature and humidity were measured with a Onset HOBO® U12 datalogger. Relative humidity of 100% was achieved by placing the sample in a sealed container containing water. Sample masses were measured with a Mettler Toleda AR201 analytical balance with a repeatability (sd) of 0.04 mg and readability of 0.01 mg. BET N 2 analysis. Adsorption/desorption isotherms were measured under N 2 at -195.8 °C on a Micromeritics® TriStar II Plus surface area and porosity analyzer. The meteorites were characterized by applying the BET N 2 sorption method. Data was analyzed using the t-Plot method assuming a Harkins and Jura thickness equation and BJH analyses with Halsey-Faas correction to derive the pore data. Measurements were made on Tarda (C2-ung), Ivuna (CI1), Orgueil (CI1), Aguas Zarcas (CM2), Murchison (CM2), and for comparison the anhydrous carbonaceous chondrite Allende (CV). Sample sizes for the BET measurements were on the order of 0.5 to 0.8 g. Samples were run as mm-sized fragments and some as powders. In this paper, the outgassing pretreatment is listed after the meteorite name: Tarda-100 refers to the sample outgassed at 100 °C under flowing N 2 for 24 hr; after prolonged storage under a dry N 2 atmosphere (-NH); after being held under a vacuum for 24 hr at room temperature (-VRT); and, after heating in the presence of flowing dry nitrogen at 250 °C for 24 hr (-250). The BET measurements were acquired over the relative pressure range p/p 0 (p is the actual gas pressure and p 0 is the vapor pressure of the adsorbing gas) of 0 to 0.99, which corresponds to the absolute pressure of ~0.8 to 730 mmHg. A value of 0.1620 nm 2 was used as the molecular cross section area for N 2 . Powder X-ray diffraction. Powder XRD patterns were acquired with a Rigaku MiniFlex 600 diffractometer. This diffractometer is operated with Cu K a radiation and is equipped with a post-diffraction graphite monochromator and automatic divergence slit system. Data were acquired from 2° to 65° 2q at 0.02° steps, and 30 to 60 s/step. XRD samples were prepared from an ~1- to 2-mm-sized fragment, which weighed ~10 mg. The chips were crushed and lightly ground to a fine powder and mixed with a few milliliters of dry methanol. The resulting slurry was pipetted and spread into a thin, smooth film on a low-background, single-crystal, quartz plate. This slurry was dried rapidly (~5 s) under flowing warm air forming a thin film. Selected prepared XRD slides were subjected to standard clay mineral treatments (Moore and Reynolds 1989) prior to X-ray data acquisition, viz., ethylene glycol vapor at 60° C for 24 hr and heating to 300° C under air for 1 hr. TG-DTA/DSC. Thermal measurements were performed on a Setaram LabsysEvo (Lyon, France) TG-DTA/DSC system, in flowing (60 mL/min) purging gas atmosphere [99.9999% purity He /DTA/, 99.999% purity Ar /DSC/ and 99.999% purity synthetic air (20% O 2 in N 2 ) /DSC/ atmospheres]. The sample was weighed into a 100 μL Al 2 O 3 crucible (the reference crucible was empty) and heated from 25 to 1000 °C with a heating rate of 10 °C/min. The obtained data was baseline corrected and further processed with the thermoanalyzer’s processing software (Calisto Processing, ver. 2.092). The thermal analyzer (both the temperature scale and calorimetric sensitivity) was calibrated by a multipoint calibration method, in which seven different certified reference materials (CRM’s) were used to cover the thermal analyzer’s entire operating temperature range. TG-DSC-MSEGA. Thermal measurements were performed on a Setaram LabsysEvo (Lyon, France) TG-DSC system, in flowing (90 mL/min) helium gas (99.9999% purity) atmosphere. The sample was weighed directly into a 100 μL Al 2 O 3 crucible (the reference cell was empty) and was heated from 25 to 1000 °C with a heating rate of 20 °C/min. The obtained data was baseline corrected and further processed with the thermoanalyzer’s processing software (Calisto Processing, ver. 2.092). The thermal analyzer (both the temperature scale and calorimetric sensitivity) was calibrated by a multipoint calibration method, in which seven different certified reference materials (CRM’s) were used to cover the thermal analyzer’s entire operating temperature range. In parallel with the thermal measurements, the analysis of evolved gases/volatiles was performed on a Pfeiffer Vacuum Omni Star™ mass spectrometric evolved gas analysis system (MS-EGA), which was connected to the above-mentioned thermal analyzer. The gas splitter was thermostated to 230 °C, while the transfer line to the mass spectrometer was thermostated to 220 °C. The temperature of the mass spectrometer gas inlet was programmed to 120 °C. The measurements were done in SEM Bargraph Cycles acquisition mode, where the m/z interval of 11-130 was continuously scanned with a speed of 50 ms/amu. The spectrometer was operated in electron impact mode. Tarda artificial weathering. Approximately 33 mg of dried, as received, Tarda powder was mixed with 100 mL of ultrapure water and allowed to evaporate to dryness. TG-DSC-MSEGA data were acquired from the dried powder. Declarations Acknowledgements This research was made possible through the generosity of the Boudreaux Family Foundation for the donation of the Tarda samples and to Michael Farmer and Carleton Moore who donated pristine samples of Aguas Zarcas to the Buseck Center for Meteorite studies. The authors are grateful for the support for this research provided by the NASA YORPD program through grant 80NSSC22K0238. L.G. is grateful to Prof. James Bell for the use of the powder x-ray diffractometer in the Planetary Space Extreme Environments Laboratory at Arizona State University, and to Dr Sarah McGregor and Mr. Anthony (A.J.) Woolson for acquiring the BET data in the METAL Core of the Eyring Materials Center at ASU. References Kuila, U. & Prasad, M. Specific surface area and pore‐size distribution in clays and shales. Geophys. Prospect. 61 , 341-362 (2013). Wigger, C., Gimmi, T., Muller, A. & Van Loon, L. R. The influence of small pores on the anion transport properties of natural argillaceous rocks–A pore size distribution investigation of Opalinus Clay and Helvetic Marl. Appl. Clay Sci. 156 , 134-143 (2018). Consolmagno, G. J., Britt, D. T. & Macke, R. J. The significance of meteorite density and porosity. Chem. Erde 68 , 1-29 (2008). Flynn, G. J., Moore, L. B. & Klöck, W. Density and porosity of stone meteorites: Implications for the density, porosity, cratering, and collisional disruption of asteroids. Icarus 142 , 97-105 (1999). Flynn, G. J., Consolmagno, G. J., Brown, P. & Macke, R. J. Physical properties of the stone meteorites: Implications for the properties of their parent bodies. Chem. Erde 78 , 269-298 (2018). Macke, R. J., Consolmagno, G. J. & Britt, D. T. Density, porosity, and magnetic susceptibility of carbonaceous chondrites. Meteorit. Planet. Sci. 46 , 1842-1862 (2011). Bland, P. A. et al. Why aqueous alteration in asteroids was isochemical: High porosity≠ high permeability. Earth Planet. Sci. Lett. 287 , 559-568 (2009). Huang, B., Bartholomew, C. H. & Woodfield, B. F. Improved calculations of pore size distribution for relatively large, irregular slit-shaped mesopore structure. Microporous Mesoporous Mater. 184 , 112-121 (2014). Landers, J., Gor, G. Y. & Neimark, A. V. Density functional theory methods for characterization of porous materials. Colloids Surf. A 437 , 3-32 (2013). Thommes, M. & Cychosz, K. A. Physical adsorption characterization of nanoporous materials: progress and challenges. Adsorption 20 , 233-250 (2014). Thommes, M. et al. Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure Appl. Chem. 87 , 1051-1069 (2015). Brunauer, S., Emmett, P. H. & Teller, E. Adsorption of gases in multimolecular layers. J. Am. Chem. Soc. 60 , 309-319 (1938). Sing, K. The use of nitrogen adsorption for the characterisation of porous materials. Colloids Surf. A 187 , 3-9 (2001). Sing, K. S. W. Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984). Pure Appl. Chem. 57 , 603-619 (1985). Dogan, A. U. et al. Baseline studies of the clay minerals society source clays: specific surface area by the Brunauer Emmett Teller (BET) method. Clays Clay Miner. 54 , 62-66 (2006). Liu, K. & Ostadhassan, M. The impact of pore size distribution data presentation format on pore structure interpretation of shales. Adv.Geo-Energy Res. 3 , 187-197 (2019). Mastalerz, M., Hampton, L., Drobniak, A. & Loope, H. Significance of analytical particle size in low-pressure N 2 and CO 2 adsorption of coal and shale. Int. J Coal Geol. 178 , 122-131 (2017). Yuan, Y. et al. Compositional controls on nanopore structure in different shale lithofacies: A comparison with pure clays and isolated kerogens. Fuel 303 , 121079 (2021). Fanale, F. P. & Cannon, W. A. Surface properties of the Orgueil meteorite: implications for the early history of solar system volatiles. Geochim. Cosmochim. Acta 38 , 453-470 (1974). Jänchen, J., Feist, M. & Möhlmann, D. T. F. Adsorption and thermoanalytical studies on the CI chondrite Orgueil as case of early preplanetary matter. Thermochim. Acta 614 , 177-184 (2015). https://doi.org:10.1016/j.tca.2015.06.025 Mautner, M. N. Formation, chemistry and fertility of extraterrestrial soils: cohesion, water adsorption and surface area of carbonaceous chondrite. Prebiotic and space resource applications. Icarus 137 , 178-195 (1999). Lauretta, D. S. et al. OSIRIS-REx: Sample Return from Asteroid (101955) Bennu. Space Sci. Rev. 212 , 925-984 (2017). https://doi.org:10.1007/s11214-017-0405-1 Chesley, S. R. et al. Orbit and bulk density of the OSIRIS-REx target Asteroid (101955) Bennu. Icarus 235 , 5-22 (2014). Nakamura, E. et al. On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective. Proc. Jpn Acad., Series B 98 , 227-282 (2022). https://doi.org:10.2183/pjab.98.015 Yokoyama, T. et al. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites. Science 379 , 1-10 (2023). https://doi.org:doi:10.1126/science.abn7850 Fuchs, L. H., Olsen, E. & Jensen, K. J. Mineralogy, mineral-chemistry, and composition of the Murchison (C2) meteorite. Smithson. Contrib. Earth Sci. 10 , 39 (1973). Garvie, L. A. J. Mineralogy of the 2019 Aguas Zarcas (CM2) carbonaceous chondrite meteorite fall. Am. Min. 106 , 1900-1916 (2021). Howard, K. T., Alexander, C. M. O. D., Schrader, D. L. & Dyl, K. A. Classification of hydrous meteorites (CR, CM and C2 ungrouped) by phyllosilicate fraction: PSD-XRD modal mineralogy and planetesimal environments. Geochim. Cosmochim. Acta 149 , 206-222 (2015). King, A. J., Schofield, P. F., Howard, K. T. & Russell, S. S. Modal mineralogy of CI and CI-like chondrites by X-ray diffraction. Geochim. Cosmochim. Acta 165 , 148-160 (2015). https://doi.org:10.1016/j.gca.2015.05.038 King, A. J., Solomon, J. R., Schofield, P. F. & Russell, S. S. Characterising the CI and CI-like carbonaceous chondrites using thermogravimetric analysis and infrared spectroscopy. Earth, Planets and Space 67 , 1-12 (2015). Suttle, M. D., King, A. J., Schofield, P. F., Bates, H. C. & Russell, S. S. The aqueous alteration of CM chondrites, a review. Geochim. Cosmochim. Acta 299 , 219-256 (2021). Tomeoka, K. & Buseck, P. R. Matrix mineralogy of the Orgueil CI carbonaceous chondrtie. Geochim. Cosmochim. Acta 52 , 1627-1640 (1988). https://doi.org:10.1016/0016-7037(88)90231-1 Garvie, L. A. J. in 49th Annual Lunar and Planetary Science Conference. 2085. Garvie, L. A. J. & Trif, L. in 52nd Lunar and Planetary Science Conference. 2446. Garvie, L. A. J. in 54th Lunar and Planetary Science Conference Abstract #2274 (Lunar and Planetary Institute, Houston, 2023). Elmaleh, A. et al. Formation and transformations of Fe-rich serpentines by asteroidal aqueous alteration processes: A nanoscale study of the Murray chondrite. Geochim. Cosmochim. Acta 158 , 162-178 (2015). Lee, M. R., Lindgren, P. & Sofe, M. R. Aragonite, breunnerite, calcite and dolomite in the CM carbonaceous chondrites: High fidelity recorders of progressive parent body aqueous alteration. Geochim. Cosmochim. Acta 144 , 126-156 (2014). Barrer, R. M. & MacLeod, D. M. Intercalation and sorption by montmorillonite. Trans. Faraday Soc. 50 , 980-989 (1954). Quirk, J. P. & Aylmore, L. A. G. Domains and quasi‐crystalline regions in clay systems. Soil Sci. Soc. Am. J. 35 , 652-654 (1971). Mackinnon, I. D. R. in 11th Lunar and Planetary Science Conference. 839-852 (Pergamon Press). Tomeoka, K., McSween Jr, H. Y. & Buseck, P. R. in Proceedings of the NIPR Symposium on Antarctic Meteorites. 221-234. Zega, T. J., Garvie, L. A. J., Dódony, I. & Buseck, P. R. Serpentine nanotubes in the Mighei CM chondrite. Earth Planet. Lett. 223 , 141-146 (2004). Zega, T. J. et al. Polyhedral serpentine grains in CM chondrites. Meteoritics & Planetary Science 41 , 681-688 (2006). Garenne, A. et al. The abundance and stability of “water” in type 1 and 2 carbonaceous chondrites (CI, CM and CR). Geochim. Cosmochim. Acta 137 , 93-112 (2014). King, A. J., Bates, H. C., Schofield, P. F. & Russell, S. S. in 52nd Lunar and Planetary Science Conference. 1909. Yesiltas, M. et al. Compositional and spectroscopic investigation of three ungrouped carbonaceous chondrites. Meteor. Planet. Sci. 57 , 1665-1687 (2022). Yokoyama, T. et al. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites. Science 379 , eabn7850 (2022). MacEwan, D. M. C. & Wilson, M. J. in Crystal Structures of Clay Minerals and their X-ray Identification (eds G.W. Brindley & G. Brown) 197-248 (Mineralogical Society, 1980). Emerson, W. W. The swelling of Ca‐montmorillonite due to water absorption: I. Water uptake in the vapour phase. J. Soil Sci. 13 , 31-39 (1962). Emerson, W. W. The swelling of Ca-montmorillonite due to water adsorption 2. Water uptake in the liquid phase. J. Soil Sci. 13 , 40-45 (1962). Ferrage, E. Investigation of the interlayer organization of water and ions in smectite from the combined use of diffraction experiments and molecular simulations. A review of methodology, applications, and perspectives. Clays Clay Miner. 64 , 348-373 (2016). Hatch, C. D. et al. Water adsorption on clay minerals as a function of relative humidity: application of BET and Freundlich adsorption models. Langmuir 28 , 1790-1803 (2012). Hofmann, U. & Bilke, W. Über die Innerkristalline Quellung und das Basenaustauschvermögen des Montmorillonits. Kolloid-Zeitschrift 77 , 238-251 (1936). Brindley, G. W. in Crystal Structures of Clay Minerals and their X-ray Identification (eds G.W. Brindley & G. Brown) 125-196 (Mineralogical Society, 1980). Reynolds, R. C. in Crystal Structures of Clay Minerals and their X-ray Identification (eds G.W. Brindley & G. Brown) 249-304 (Mineralogical Society, 1980). Garvie, L. A. J. & Buseck, P. R. Prebiotic carbon in clays from Orgueil and Ivuna (CI), and Tagish Lake (C2 ungrouped) meteorites. Meteor. Planet. Sci. 42 , 2111-2117 (2007). Emerson, W. W. The slaking of soil crumbs as influenced by clay mineral composition. Aust. J. Soil Res. 2 , 211-217 (1964). Berzelius, J. J. Ueber Meteorsteine. IV Meteorstein von Alais. Ann. Phys. Chem. 33 , 113-148 (1834). Additional Declarations No competing interests reported. Supplementary Files N2BETSupplDataSciRep.docx Tardaslaking.mp4 Cite Share Download PDF Status: Published Journal Publication published 06 May, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 16 Feb, 2024 Reviews received at journal 23 Jan, 2024 Reviewers agreed at journal 21 Jan, 2024 Reviewers invited by journal 21 Jan, 2024 Editor assigned by journal 21 Jan, 2024 Editor invited by journal 20 Jan, 2024 Submission checks completed at journal 20 Jan, 2024 First submitted to journal 11 Jan, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3854166","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":268487095,"identity":"76a8798c-34cd-4081-a4d9-03df99ad51f2","order_by":0,"name":"Laurence A.J. Garvie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsElEQVRIiWNgGAWjYLCCBAYbCIOHBC1ppGphYDhMghZ597PPJB5UnJeXn5HA+OBtGxFaDM+km0kknLltuOFGArPhXKK0NKQxGyS23WbcIJHAJs1LlJb+Z0At/87Zz5+RwP6bKC3yEmmMDxIbDiQ23EhgYyZKi4HEM8YHCceSkzecedgsOeccMbb0pzEc/FFjZzu/PfnghzdlxNhyAM5kbCBCPcgWItWNglEwCkbBSAYAAxk2UQOSmgwAAAAASUVORK5CYII=","orcid":"","institution":"Arizona State University","correspondingAuthor":true,"prefix":"","firstName":"Laurence","middleName":"A.J.","lastName":"Garvie","suffix":""},{"id":268487096,"identity":"692f1657-732a-494d-b057-ef18126cf9a3","order_by":1,"name":"László Trif","email":"","orcid":"","institution":"Research Centre for Natural Sciences","correspondingAuthor":false,"prefix":"","firstName":"László","middleName":"","lastName":"Trif","suffix":""},{"id":268487097,"identity":"be98d54e-464e-4003-ae64-ff0cf9424b39","order_by":2,"name":"Desireé Cotto-Figueroa","email":"","orcid":"","institution":"The University of Puerto Rico at Humacao","correspondingAuthor":false,"prefix":"","firstName":"Desireé","middleName":"","lastName":"Cotto-Figueroa","suffix":""},{"id":268487098,"identity":"2b5e8067-d291-498f-8808-dc4ad9b8286e","order_by":3,"name":"Erik Asphaug","email":"","orcid":"","institution":"University of Arizona","correspondingAuthor":false,"prefix":"","firstName":"Erik","middleName":"","lastName":"Asphaug","suffix":""},{"id":268487099,"identity":"ee5a1469-43d3-4b4f-a3c7-44d19be049d8","order_by":4,"name":"Christian G. Hoover","email":"","orcid":"","institution":"Arizona State University","correspondingAuthor":false,"prefix":"","firstName":"Christian","middleName":"G.","lastName":"Hoover","suffix":""}],"badges":[],"createdAt":"2024-01-11 16:59:47","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3854166/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3854166/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-024-61114-2","type":"published","date":"2024-05-06T17:01:38+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":49973241,"identity":"dc17e978-452c-434d-afe6-896dc5add331","added_by":"auto","created_at":"2024-01-22 14:04:24","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":789162,"visible":true,"origin":"","legend":"\u003cp\u003eN\u003csub\u003e2\u003c/sub\u003e BET isotherms measured at 77 K for selected meteorites. \u003cstrong\u003e(a)\u003c/strong\u003e Adsorption isotherms for Tarda after different outgassing pretreatments. Blue squares – Tarda-NH, black diamonds – Tarda-VRT, green circles – Tarda-100, and purple triangles – Tarda-250. \u003cstrong\u003e(b)\u003c/strong\u003e Adsorption-desorption isotherms for Tarda-250 (adsorption – purple triangles, desorption – green circles) and Tarda-NH (adsorption - blue squares, desorption – black diamonds). \u003cstrong\u003e(c)\u003c/strong\u003e Adsorption (blue squares)-desorption (black diamonds) isotherm for Ivuna. \u003cstrong\u003e(d)\u003c/strong\u003e Adsorption (black diamonds)-desorption (blue squares) isotherm for Aguas Zarcas.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/1e581dd189479f043739056a.png"},{"id":49973242,"identity":"11bd14bc-cc26-4093-9913-ea440ce961b8","added_by":"auto","created_at":"2024-01-22 14:04:24","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":764699,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of the logarithmic differential pore-volume distribution, dV/d (log(w)) versus pore width calculated from the N\u003csub\u003e2\u003c/sub\u003e BET data with the Halsey Faas correction. \u003cstrong\u003e(a)\u003c/strong\u003e Pore-volume distribution for Tarda for different outgassing pretreatments derived from the adsorption isotherms. Blue squares – Tarda-NH, black diamonds – Tarda-VRT, green circles – Tarda-100, and purple diamonds – Tarda-250. \u003cstrong\u003e(b)\u003c/strong\u003e Comparison of the pore-volume distribution for Tarda-100 (green circles), Ivuna (black diamonds), Aguas Zarcas (red circles), and Allende (blue squares). The numbered regions 1 to 3 correspond to the micro-, meso- and macropore volumes, respectively. \u003cstrong\u003e(c)\u003c/strong\u003e Pore-volume distribution for Tarda-100 derived from the adsorption isotherm (blue squares) and desorption isotherm (black diamonds). \u003cstrong\u003e(d)\u003c/strong\u003e Pore-volume distribution for Aguas Zarcas derived from the adsorption isotherm (blue squares) and desorption isotherm (black diamonds).\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/0198e846cc74a591bed27d79.png"},{"id":49973244,"identity":"a48b00e6-0e5b-4f49-bf34-959f40e0edef","added_by":"auto","created_at":"2024-01-22 14:04:24","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":982057,"visible":true,"origin":"","legend":"\u003cp\u003eTG-DSC-MSEGA for Tarda before and after artificial weathering. (\u003cstrong\u003ea\u003c/strong\u003e) TG, (\u003cstrong\u003eb\u003c/strong\u003e) DSC, (\u003cstrong\u003ec\u003c/strong\u003e) MSEGA for m/z=18 (H\u003csub\u003e2\u003c/sub\u003eO), and (\u003cstrong\u003ed\u003c/strong\u003e) MSEGA for m/z=44 (CO\u003csub\u003e2\u003c/sub\u003e) curves for Tarda curated under nitrogen (green curves) and artificially weathered with water (purple curves). Data shown for the low temperature region to 200 °C. The complete data to 1000 °C are shown in Figs. S11 to S15.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/f855c053984634551b831250.png"},{"id":49973243,"identity":"db592afe-81be-44d5-9428-bc1453a5880b","added_by":"auto","created_at":"2024-01-22 14:04:24","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":693200,"visible":true,"origin":"","legend":"\u003cp\u003ePowder X-ray diffraction patterns from Tarda. (\u003cstrong\u003ea\u003c/strong\u003e) Low-angle powder XRD patterns from Tarda after heating to 300 °C, at 0% RH and 23°C, at 34% RH and 23°C, 100% RH and 32 °C, and after placing the XRD slide over ethylene glycol (EGL) for 24 hrs at 60 °C in a sealed container. (\u003cstrong\u003eb\u003c/strong\u003e) Powder XRD pattern from the same Tarda sample after drying (1 hr) and after 12 and 48 hrs at 100% RH showing the formation of gypsum. The patterns have been shifted along the y-axis for clarity. The individual patterns were scaled to the intensity of the 7.4 Å peak for the sample heated to 300 °C.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/e7eb955e1c28c00b1906ed26.png"},{"id":49973491,"identity":"d3b1823d-1117-411d-ac17-67a2bebb58cc","added_by":"auto","created_at":"2024-01-22 14:12:24","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":4790332,"visible":true,"origin":"","legend":"\u003cp\u003ePhotograph of a Tarda fragment after 14 days at 32°C and 100% RH. The sample shows extensive cracking and formation of gypsum (small white dots).\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/06e25be83f876b5604a4bdbd.png"},{"id":56195521,"identity":"93e20277-edfb-417c-bf1c-0c46239f6abe","added_by":"auto","created_at":"2024-05-09 18:02:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5567395,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/86a2d5de-5678-4a97-a921-8db6005cb65f.pdf"},{"id":49973246,"identity":"9f5ad651-df03-4f62-ac24-a92dc5dc60fe","added_by":"auto","created_at":"2024-01-22 14:04:25","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":3887544,"visible":true,"origin":"","legend":"","description":"","filename":"N2BETSupplDataSciRep.docx","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/7346767dce367adb36ad2ff8.docx"},{"id":49973247,"identity":"a6094f15-138f-4f98-ad15-5df5e5561e03","added_by":"auto","created_at":"2024-01-22 14:04:25","extension":"mp4","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":6092262,"visible":true,"origin":"","legend":"","description":"","filename":"Tardaslaking.mp4","url":"https://assets-eu.researchsquare.com/files/rs-3854166/v1/de852f49cadb612fbc9d4f52.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"High surface area and interconnected nanoporosity of clay-rich astromaterials","fulltext":[{"header":"Introduction","content":"\u003cp\u003eClay-rich rocks have complex pore structures controlled by the microstructure and aggregation of the clays. Their multiscale clay-aggregate structure can give rise to high surface areas dominated by nanometer-scale porosity with different dimensions and scales \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. This porosity, pore-size distribution, and pore connectivities are important properties in clay-rich rocks that affects their strength, thermal conductivity, speed, and attenuation of sound, and transport of fluids. Although there has been significant research on the bulk porosity of meteorites \u003csup\u003e\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e, the bulk submicron-scale porosity in CCs is relatively understudied. This submicron porosity, and in particular bulk fine-scale porosity and pore-size distribution can be probed through a range of techniques including X-ray tomography, transmission electron microscopy, NMR cryoporometry, and inert gas adsorption \u003csup\u003e\u003cspan additionalcitationids=\"CR8 CR9 CR10\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Of these methods, physical adsorption of an inert gas, such as nitrogen is widely used to probe the surface area and bulk fine-scale porosity and pore-size distribution \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNitrogen gas adsorption can reveal information on the total surface area and nanometer-scale pore characteristics for pores\u0026thinsp;\u0026lt;\u0026thinsp;200 nm in diameter. Insights into the adsorption process is provided by application of the Brunauer-Emmett-Teller (BET) theory \u003csup\u003e\u003cspan additionalcitationids=\"CR12 CR13\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Pore sizes accessible to N\u003csub\u003e2\u003c/sub\u003e BET are divided into micropores (\u0026lt;\u0026thinsp;2 nm), mesopores (2 to 50 nm), and macropores (\u0026gt;\u0026thinsp;50 nm) \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. The BET and the Barrett, Joyner, and Halenda (BJH) method has been applied to create pore volume and surface area distributions based on adsorption-desorption isotherms for a wide range of terrestrial clays and shales \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Despite extensive research on terrestrial clays and argillaceous rocks, only limited BET gas adsorption research has been conducted on clay-rich meteorites \u003csup\u003e\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Consequently, the surface area and nanopore-size distribution in these meteorites, and by extension their parent asteroids remains poorly understood.\u003c/p\u003e \u003cp\u003eThe current motivation to study C-type astromaterials free of terrestrial contamination propelled return missions to two Near Earth Objects (NEOs) \u0026minus;\u0026thinsp;162173 Ryugu and 101955 Bennu. Bennu was chosen as the target of OSIRIS-REx \u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e in part due to its spectral similarities to primitive, organic-rich CCs and for its potential to impact Earth between the years 2175 and 2199 \u003csup\u003e23\u003c/sup\u003e. On 20th October 2020, OSIRIS-REx touched down on Bennu and returned\u0026thinsp;~\u0026thinsp;100 g on the 24th of September 2023. The Hayabusa2 mission returned samples from the potentially hazardous asteroid Ryugu. The Ryugu and Bennu samples show close mineralogical similarities with the CI1 CCs \u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e,\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e, establishing a direct relationship between meteorites and their parent asteroids.\u003c/p\u003e \u003cp\u003eMany petrologic types 1 and 2 CCs, including the samples returned from asteroids Ryugu and Bennu, are dominated by phyllosilicates \u003csup\u003e\u003cspan additionalcitationids=\"CR27 CR28 CR29 CR30 CR31\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. The bulk powder low-angle X-ray diffraction (XRD) patterns show that their clays are broadly divided into serpentines and smectites or a combination thereof \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan additionalcitationids=\"CR34\" citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. Clay-rich rocks can have complex pore structures controlled by the microstructure and aggregation of the clays. A multiscale clay aggregate structure gives rise to porosity with different dimensions and scales \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. This porosity, pore-size distribution, and pore connectivities are important properties in clay-rich rocks as they affect key properties of the astromaterial including strength, thermal conductivity, speed, and attenuation of sound \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e, and on transport of fluids on the early parent body that gives rise to the complex, multiscale mineralogies, e.g., \u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e,\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn this study, we explore the surface area, fine-scale porosity, and pore-size distribution in clay-rich CC meteorites with the N\u003csub\u003e2\u003c/sub\u003e BET gas adsorption method and apply the BJH analysis to create pore volume and surface area distributions based on the adsorption-desorption isotherms. Our primary focused is on the recent Tarda (C2-ung) fall. For comparison, BET data is also acquired from four well-studied clay-rich CC falls, Ivuna (CI1), Orgueil (CI1), Aguas Zarcas (CM2), and Murchison (CM2), and an anhydrous CC, Allende (CV3). A major finding of our study is that Tarda has high surface area, up to 82 m\u003csup\u003e2\u003c/sup\u003e/g, and a pore-size distribution, obtained by applying the BJH method from the adsorption isotherm, with a maximum near the upper boundary with the micropore range and a broad tail into the macropore region. In contrast, the other clay-rich meteorites have lower surface areas (13.8 to 18.6 m\u003csup\u003e2\u003c/sup\u003e/g), and bimodal pore-size distributions with less-pronounced maximum near 3-nm peak and broader more intense distribution that straddles the meso- macropore boundary. The Tarda data advocates for a high density of intra-tachoid pores, in, around and between the nano-sized aggregates of poorly ordered clays. It is speculated that the recently returned asteroid samples from Ryugu and Bennu, which show mineralogical similarities to Tarda, will also show a similarly high surface area and fine-scale, interconnected nanoporosity.\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003e \u003cb\u003eNitrogen adsorption and surface area measurements.\u003c/b\u003e \u003c/p\u003e \u003cp\u003ePrior to entering the Earth atmosphere, meteorites and asteroid returned samples inhabit the ultrahigh vacuum of space, with a pressure near 1.3 x 10\u003csup\u003e\u0026minus;\u0026thinsp;11\u003c/sup\u003e Pa, equivalent to at most a few tens of atoms/cm\u003csup\u003e3\u003c/sup\u003e. However, once on Earth, they immediately adsorb our atmosphere which exposes their surface area to atmospheric gases. Therefore, prior to the N\u003csub\u003e2\u003c/sub\u003e BET measurements, it is necessary to remove these physisorbed species through outgassing \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. In this paper, the outgassing pretreatment is listed after the meteorite name: Tarda-100 refers to the sample outgassed at 100\u0026deg;C under flowing N\u003csub\u003e2\u003c/sub\u003e for 24 hr; after prolonged storage under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere (-NH); after being held under a vacuum for 24 hr at room temperature (-VRT); and, after heating in the presence of flowing dry nitrogen at 250\u0026deg;C for 24 hr (-250) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The N\u003csub\u003e2\u003c/sub\u003e BET measurements are made by exposing the degassed sample to N\u003csub\u003e2\u003c/sub\u003e at a series of controlled pressures while maintaining the sample at a constant cryogenic temperature of -195.8\u0026deg;C, which corresponds to the boiling point of N\u003csub\u003e2\u003c/sub\u003e. The volume of adsorbed or desorbed gas is measured over a relative equilibrium adsorption pressure (p/p\u003csup\u003e0\u003c/sup\u003e) from near 0 to 1, where p is the absolute equilibrium pressure and p\u003csup\u003e0\u003c/sup\u003e the saturation pressure of the gas \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. The plot of p/p\u003csup\u003e0\u003c/sup\u003e versus the quantity of gas adsorbed is called the adsorption isotherm. Prior to the N\u003csub\u003e2\u003c/sub\u003e BET analyses, all samples were checked first by powder X-ray diffraction (See Supplementary Data, Figs. S1, S2, and details in the Experimental section).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMeteorites studied, degas conditions, BET surface area (S\u003csub\u003eBET\u003c/sub\u003e), BET C parameter (C), monolayer capacity - \u003cb\u003en\u003c/b\u003e\u003csub\u003em\u003c/sub\u003e, BJH adsorption cumulative volume of pores (V\u003csub\u003ead\u003c/sub\u003e), BJH desorption cumulative volume of pores (V\u003csub\u003eds\u003c/sub\u003e), and pore size for selected meteorites determined from the N\u003csub\u003e2\u003c/sub\u003e adsorption isotherms at 77 K.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMeteorite\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDegas\u003c/p\u003e \u003cp\u003eCondition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003en\u003csub\u003em\u003c/sub\u003e (cm\u003csup\u003e2\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eS\u003csub\u003eBET\u003c/sub\u003e (m\u003csup\u003e2\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eV\u003csub\u003ead\u003c/sub\u003e (cm\u003csup\u003e3\u003c/sup\u003e/g)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eV\u003csub\u003eds\u003c/sub\u003e (cm\u003csup\u003e3\u003c/sup\u003e/g)\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003ePore size\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003enm\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e189.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18.7499\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e81.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0907\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0999\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e4.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e124.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e16.0960\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e70.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0821\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0894\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e4.91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003csup\u003e\u003cb\u003ep\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e104.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e14.9255\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e64.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0757\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0967\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e5.96\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003csup\u003e\u003cb\u003eg\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.0047\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e47.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0634\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0683\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e5.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVRT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e98.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e15.1008\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e49.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0671\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0719\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e5.29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTarda\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e59.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.7325\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e33.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0531\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0507\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e5.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eIvuna\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e106.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.2185\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e18.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0828\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0840\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOrgueil\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e95.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.4934\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e15.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0643\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0652\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAguas Zarcas\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e134.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.7734\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e16.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0588\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0613\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e14.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAguas Zarcas\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e131.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.3602\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e10.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0407\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0263\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMurchison\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.1727\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e13.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0524\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0545\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e14.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAllende\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e64.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.2775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e1.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.0074\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0082\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e29.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e\u003cb\u003ep\u003c/b\u003e \u0026ndash; powder, \u003cb\u003eg\u003c/b\u003e \u0026ndash; exposed to 100% RH at 32\u0026deg;C for 24 hours forming gypsum, and then degassed under flowing N\u003csub\u003e2\u003c/sub\u003e at 100\u0026deg;C. \u003cb\u003eNH\u003c/b\u003e \u0026ndash; sample not outgassed at 100\u0026deg;C for 24 hr. \u003cb\u003eVRT\u003c/b\u003e \u0026ndash; outgassed at room temperature under vacuum for 24 hr. \u003cb\u003e100\u003c/b\u003e \u0026ndash; outgassed under flowing dry N\u003csub\u003e2\u003c/sub\u003e at 100\u0026deg;C for 24 hr. \u003cb\u003e250\u003c/b\u003e \u0026ndash; outgassed under flowing dry N\u003csub\u003e2\u003c/sub\u003e at 250\u0026deg;C for 24 hr. \u003cb\u003e1\u003c/b\u003e - BJH Adsorption cumulative volume of pores between 1.7 nm and 300.0 nm width. \u003cb\u003e2\u003c/b\u003e - BJH Desorption cumulative volume of pores between 1.7 nm and 300.0 nm width. \u003cb\u003e3\u003c/b\u003e - BJH Adsorption average pore width (4V/A).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe Tarda adsorption isotherms show six distinct regions (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea) \u0026ndash; a near vertical rise in adsorption for p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.02 (Fig. S3), a broad kink in the adsorption volume up to p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.05, an almost linear increase in p/p\u003csup\u003e0\u003c/sup\u003e to ~\u0026thinsp;0.35, slightly non-linear positive adsorption to p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.9, after which there is a slight flattening for p/p\u003csup\u003e0\u003c/sup\u003e between 0.9 and 0.95, followed by an asymptotic increase in adsorption at p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;1 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Comparison of these isotherms with the Brunauer-Deming-Deming-Teller (BDDT) physisorption isotherm types \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e shows that Tarda possesses a hybrid adsorption isotherm with a Type 1b onset followed by a Type II isotherm with a hint of Type IV character at high p/p\u003csup\u003e0\u003c/sup\u003e. A Type Ib onset is interpreted as the filling of micropores with a range of pore volumes that extends into the mesopore region. The steep, almost linear increase in adsorption above p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.05, suggests a broad range of mesopore volumes. The final asymptotic increase at p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;1 can be attributed to incomplete filling of macropores, i.e., those\u0026thinsp;\u0026gt;\u0026thinsp;200 nm in diameter that are too large to be filled as p/p\u003csup\u003e0\u003c/sup\u003e approaches 1. In general, the degree of N\u003csub\u003e2\u003c/sub\u003e uptake for p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;1 is proportional to the total porosity of pores to ~\u0026thinsp;200 nm in diameter showing that outgassing significantly increases the total micro and mesoporosity. While the Tarda adsorption isotherms do not have a plateau at high p/p\u003csup\u003e0\u003c/sup\u003e, as is expected for a Type IV isotherm, the slight flattening for p/p\u003csup\u003e0\u003c/sup\u003e between 0.9 and 0.95 suggest complete filling of the mesopores up to ~\u0026thinsp;200 nm, but a lower density of large macropores remain unfilled at p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;1.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTarda shows pronounced hysteresis during desorption (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, S4), dominated by an H2 hysteresis loop pattern, though the onset of the desorption for p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.95 shows H3 character \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. The desorption isotherm does not track with the adsorption path and shows a marked hysteresis at p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.35\u0026ndash;0.45. The steepness of the desorption branch for p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.5 informs on pore-size range, pore geometry and connectivity (see below).\u003c/p\u003e \u003cp\u003eThe adsorption profiles for the smectite-rich Orgueil and Ivuna and serpentine-rich Aguas Zarcas and Murchison, all outgassed at 100\u0026deg;C, show similar adsorption profiles (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec,d, S5,6) matching a Type II isotherm. There is a small but rapid increase in adsorbed N\u003csub\u003e2\u003c/sub\u003e for p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.02, gradual uptake up to p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.8, and then rapid uptake to p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;1. Aguas Zarcas and Murchison show an H3 type desorption isotherm with rapid decrease in the desorption isotherm at 0.4\u0026thinsp;\u0026lt;\u0026thinsp;p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.5 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed, S6). The hysteresis loop of the desorption branch for Ivuna and Orgueil are more complex. Desorption of Orgueil is linear for 0.5\u0026thinsp;\u0026lt;\u0026thinsp;p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;1 with a sharp and sudden decrease from p/p\u003csup\u003e0\u003c/sup\u003e of 0.5 to 0.45 (Fig. S5). Ivuna shows linear desorption 0.85\u0026thinsp;\u0026lt;\u0026thinsp;p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;1, and H2b like hysteresis in the range 0.5\u0026thinsp;\u0026lt;\u0026thinsp;p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.85, and rapid decrease in the quantity adsorbed and closure of desorption isotherm at 0.4\u0026thinsp;\u0026lt;\u0026thinsp;p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.5 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). In contrast, Allende is largely dominated by anhydrous silicate, FeS, and metal shows a Type II adsorption isotherm and a desorption isotherm that largely tracks the adsorption pathway (Fig. S7).\u003c/p\u003e \u003cp\u003eInsights into the surface area of porous materials can be gained by application of the Brunauer-Emmet-Teller (BET) equation\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\frac{1}{\\varvec{n}(\\frac{{p}^{0}}{p}-1)}=\\frac{C-1}{{\\varvec{n}}_{m}C}\\left(\\frac{p}{{p}^{0}}\\right)+\\frac{1}{{\\varvec{n}}_{m}C}$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eto the isotherms, where \u003cb\u003en\u003c/b\u003e is the specific amount adsorbed in cm\u003csup\u003e3\u003c/sup\u003e/g at STP at relative pressure p/p\u003csup\u003e0\u003c/sup\u003e and \u003cb\u003en\u003c/b\u003e\u003csub\u003em\u003c/sub\u003e is the specific monolayer capacity \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. The specific monolayer capacity \u003cb\u003en\u003c/b\u003e\u003csub\u003em\u003c/sub\u003e is determined by plotting the BET function 1/(\u003cb\u003en\u003c/b\u003e(p\u003csup\u003e0\u003c/sup\u003e/p-1) against the relative adsorption pressure p/p\u003csup\u003e0\u003c/sup\u003e, called the BET plot \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, within the linear range of p/p\u003csup\u003e0\u003c/sup\u003e, which is typically \u0026sim;0.05\u0026ndash;0.30 for Type II and Type IVa isotherms \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. The slope of the linear regression of the linear range of the BET plot is used to derive \u003cb\u003en\u003c/b\u003e\u003csub\u003em\u003c/sub\u003e=1/(\u003cem\u003es\u003c/em\u003e\u0026thinsp;+\u0026thinsp;\u003cem\u003ei\u003c/em\u003e), where \u003cem\u003es\u003c/em\u003e is the slope and \u003cem\u003ei\u003c/em\u003e the intercept, and C\u0026thinsp;=\u0026thinsp;\u003cem\u003es\u003c/em\u003e/\u003cem\u003ei\u003c/em\u003e\u0026thinsp;+\u0026thinsp;1. The suitability of this linear BET plot is demonstrated for Tarda-100, which shows that p/p\u003csup\u003e0\u003c/sup\u003e from 0.30074 to 0.056479 lie along a straight line with R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99993 (Fig. S8) and is the region of the isotherm in which statistically the volume adsorbed corresponds to just the complete monolayer. Above and below these p/p\u003csup\u003e0\u003c/sup\u003e values the points deviate from the linear regression and are not used for the BET surface area calculation (Fig. S8). The BET surface area is calculated using,\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$${S}_{BET} =\\frac{{\\varvec{n}}_{m} \\text{L} {\\sigma }_{m}}{{V}_{0} m}$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e is the BET specific area, \u003cb\u003en\u003c/b\u003e\u003csub\u003em\u003c/sub\u003e the monolayer capacity, σ\u003csub\u003em\u003c/sub\u003e is the molecular cross-sectional area occupied by the adsorbate molecule which for N\u003csub\u003e2\u003c/sub\u003e is 16.2 x 10\u003csup\u003e\u0026minus;\u0026thinsp;20\u003c/sup\u003e m\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e (0.162 nm\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e), L is the Avogadro constant 6.022 x 10\u003csup\u003e23\u003c/sup\u003e, V\u003csub\u003e0\u003c/sub\u003e is the molar gas volume of the adsorptive at STP, and m is the mass of the sample. Using this analysis, the BET specific surface areas for the clay-rich meteorites range from 10.27 to 81.61 m\u003csup\u003e2\u003c/sup\u003e/g and only 1.21 m\u003csup\u003e2\u003c/sup\u003e/g for the anhydrous Allende (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Different degassing pretreatments have significant effects on the BET surface area with the Tarda values ranging from 33.67 m\u003csup\u003e2\u003c/sup\u003e/g for the sample taken directly from the nitrogen cabinet to 81.61 m\u003csup\u003e2\u003c/sup\u003e/g after the 250\u0026deg;C treatment. Powdering has little effect on the surface area measurement, i.e., compare Tarda-100 and Tarda\u003csup\u003ep\u003c/sup\u003e-100 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Despite the differing hysteresis patterns between the smectite-rich Orgueil and Ivuna and the serpentine-rich Aguas Zarcas and Murchison, their \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e values are close (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), though the profile differences provide information on pore-size distribution, pore geometry and network effects.\u003c/p\u003e \u003cp\u003eThe \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e values of the clay-rich meteorites measured here are within the range of terrestrial argillaceous rocks and clays \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. For example, \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e for The Clay Minerals Society source clays measured by BET N\u003csub\u003e2\u003c/sub\u003e gas adsorption ranged from 12.1 to 173 m\u003csup\u003e2\u003c/sup\u003e/g \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e, though the three natural smectites had values 22.7 to 65.2 m\u003csup\u003e2\u003c/sup\u003e/g. The \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e values for Orgueil and Ivuna are significantly less than the mineralogically similar Tarda despite the similar bulk mineralogy. The value measured here for Orgueil-100 of 15.21 m\u003csup\u003e2\u003c/sup\u003e/g is half that previously reported \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e, despite the similar degassing conditions. This difference may be the result of the varied curatorial histories of samples since its fall in 1864, however, the value measured here is still within the range for smectite-rich argillaceous rocks. In addition, the S\u003csub\u003eBET\u003c/sub\u003e data for Tarda acquired after different pretreatment and outgassing treatments varies by over a factor x2 for the sample run directly from the dry N\u003csub\u003e2\u003c/sub\u003e chamber to the one outgassed at 250\u0026deg;C under flowing N\u003csub\u003e2\u003c/sub\u003e. It is also likely the S\u003csub\u003eBET\u003c/sub\u003e values would be even higher under vacuum degassing, which would more closely replicate conditions in space.\u003c/p\u003e \u003cp\u003eInformation on the pore-size distribution and average pore size is gained using the isotherm data by employing the t-Plot method using a Harkins and Jura thickness equation and BJH analyses with Halsey-Faas correction to derive the pore data. The single-point cumulative volume of pores in the 1.7 nm and 300.0 nm width range (V\u003csub\u003ead\u003c/sub\u003e) calculated from the adsorption data for the clay-rich meteorites ranges from 0.0524 to 0.0907 cm\u003csup\u003e3\u003c/sup\u003e/g (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The same calculated from the desorption data (V\u003csub\u003eds\u003c/sub\u003e) are of a similar magnitude, though in general a few percent larger (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Despite Tarda-100 having a significantly higher S\u003csub\u003eBET\u003c/sub\u003e than Ivuna, their V\u003csub\u003ead\u003c/sub\u003e values are close. In general, V\u003csub\u003ead\u003c/sub\u003e for the serpentine-rich Aguas Zarcas and Murchison are lower than the smectite-rich meteorites, with the anhydrous Allende showing the lowest V\u003csub\u003ead\u003c/sub\u003e value. However, there are significant differences in their \u0026lt;\u0026thinsp;200 nm pore-size distributions derived from the N\u003csub\u003e2\u003c/sub\u003e BET data with the Halsey Faas correction calculated from the adsorption isotherms.\u003c/p\u003e \u003cp\u003eA commonly used method to display the pore-size distribution is through the plot of the logarithmic differential pore-volume distribution, dV/d (log(w)), versus pore width \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Here, the area under the curve in any pore diameter range yields the volume of pores in that range. These plots derived for the adsorption branch of the isotherms show that Tarda has significant mesoporosity, with a maximum near the upper boundary with the micropore range and a broad tail into the macropore region (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). The profile maximum becomes narrower and more intense from Tarda NH \u0026rarr; VRT \u0026rarr; 100 \u0026rarr; 250. In contrast, the mineralogically similar Orgueil and Ivuna have a bimodal pore-size distribution with a major maximum near 40 nm and a minor peak around 3 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb and S9). The profiles for Aguas Zarcas and Murchison show a less-pronounced 3-nm peak and broader maximum that straddles the meso- macropore boundary (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb and S10). The anhydrous Allende lacks significant microporosity and has a broad maximum near 100 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). While the application of Kelvin equation-based procedures, such as the BJH method, can with some pore geometries underestimate the pore size, e.g., \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e, the plots of pore width versus the log differential pore size for the meteorites provide a semi-quantitative view of the pore-size distribution.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn certain pore geometries the desorption isotherm can provide a more accurate representation of the pore geometry as it is thought that the desorption process is in thermodynamic equilibrium between the liquid adsorbed phase in the pores and the external gaseous phase. However, the smectite and serpentine-rich meteorites studied here all show the sudden abrupt closure of the desorption branch to the adsorption branch of the isotherm near p/p\u003csup\u003e0\u003c/sup\u003e\u0026thinsp;~\u0026thinsp;0.4. The plots of pore width versus the log differential pore size determined from the desorption isotherms of the clay-rich meteorites all show a sharp spike at 3.8 nm (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec,d). This spike is caused by rapid desorption during evaporation from the pore neck and the pore body involving cavitation and the growth of vapor bubbles in the metastable condensed fluid, and is evidence for pore restriction smaller than ~\u0026thinsp;5 to 6 nm for N\u003csub\u003e2\u003c/sub\u003e at 77 K \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe peak in the micropore-mesopore boundary region in the pore-size distribution from smectite-rich rocks is attributed to \u0026ldquo;intra-tachoid\u0026rdquo; porosity \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e. Tachoids are 2- to 50-nm sized aggregates with turbostratic stacking of the phyllosilicate TOT plates. Tarda is smectite-rich, and a maximum in the micropore region is consistent with intra-tachoid porosity. However, the rapid decrease in dV/dlog(w) with increase in pore size (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea) suggests a decreasing density of pores in the 50- to 100-nm-size range between the tachoids, whereas Orgueil, Ivuna, Aguas Zarcas, and Murchison possess significant inter-tachoid and intra-aggregate porosity. For example, HRTEM images of Orgueil show a highly disordered submicron m\u0026eacute;lange of interpenetrating platy, curved, and poorly crystalline phyllosilicates and ferrihydrite together hosting nanometer-sized sulfides \u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e, with abundant sites for intra-tachoid porosity. More recently, HRTEM images from Ryugu C1-like material shows similar fine-scale phyllosilicate complexity \u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. In both the Orgueil and Ryugu material the nanoscale tachoid nature of the matrix is evident in the HRTEM images. In contrast, the matrices of the CM2 chondrites show regions of more coarsely crystalline phyllosilicates commonly with platy and polygonal morphologies as well as regions with submicron tissue-like aggregates \u003csup\u003e\u003cspan additionalcitationids=\"CR41 CR42\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eCharacterizing the adsorbed water\u003c/h2\u003e \u003cp\u003eThe ease with which the smectite-rich meteorites adsorb and intercalate water from the atmosphere makes the determination of the indigenous molecular water challenging. The quantity of water adsorbed and retained by Tarda under normal laboratory conditions can be measured by thermal gravimetric analysis (TG) combined with mass spectrometric evolved-gas analysis system (MSEGA). MSEGA detects evolved gases that have distinct ion mass to charge ratios (m/z). These methods are used to provide information on the H\u003csub\u003e2\u003c/sub\u003eO and OH\u003csup\u003e\u0026minus;\u003c/sup\u003e content of the phyllosilicates and other H-bearing in the CC meteorites \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e,\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. The thermal analysis was recently described from Aguas Zarcas \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e and so the focus of the discussion here is on Tarda. Although samples were heated to 1000\u0026deg;C, the primary temperature range of interest here is below 300\u0026deg;C, which is within the range that the samples were heated prior to the N\u003csub\u003e2\u003c/sub\u003e BET analysis and lower than the dehydroxylation temperatures for the phyllosilicates.\u003c/p\u003e \u003cp\u003eTwo Tarda samples were analyzed. The first is a fresh powder curated under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere \u0026ndash; Tarda\u003csub\u003eN\u003c/sub\u003e. The second, called Tarda\u003csub\u003eW\u003c/sub\u003e, was a powder mixed with distilled water and allowed to dry at room temperature under ~\u0026thinsp;34% RH. The TG mass losses for Tarda\u003csub\u003eN\u003c/sub\u003e and Tarda\u003csub\u003eW\u003c/sub\u003e heated to 1000\u0026deg;C are 16.6 and 19.4%, respectively (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, S11, S12). Their TG, DSC, and MSEGA profiles are broadly similar (Figs. S11-15), though there are significant differences below 200\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The DTG curves show three prominent features near 100\u0026deg;, 510\u0026deg;, and 760\u0026deg; C, corresponding to the significant rates of change in the TG mass loss curve. The first mass loss step for Tarda\u003csub\u003eN\u003c/sub\u003e and Tarda\u003csub\u003eW\u003c/sub\u003e between 60\u0026deg; and 200\u0026deg;C are Δm \u0026minus;\u0026thinsp;1.011% and \u0026minus;\u0026thinsp;3.013%, respectively (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea, S11,12). This first mass loss step corresponds to the loss of adsorbed water and water intercalated with the smectite clays. The 100\u0026deg;C peak in the DTG curve corresponds to the endothermic peak in the DSC curve (Fig. S14).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe identity of the gas species evolved corresponding to specific regions of the TG loss curve is revealed by the MSEGA data. A wide range of ion species are evolved during heating and most of the ion signals for Tarda\u003csub\u003eN\u003c/sub\u003e and Tarda\u003csub\u003eW\u003c/sub\u003e are similar over the 1000\u0026deg;C range (Fig. S15). However, below 300\u0026deg;C there are yield differences for m/z\u0026thinsp;=\u0026thinsp;18, 30, and 44. The most abundant gas released below 300\u0026deg;C has m/z\u0026thinsp;=\u0026thinsp;18 corresponding to H\u003csub\u003e2\u003c/sub\u003eO and its signal is significantly more intense for Tarda\u003csub\u003eW\u003c/sub\u003e. The signal for m/z\u0026thinsp;=\u0026thinsp;44, corresponding to CO\u003csub\u003e2\u003c/sub\u003e, is more intense for Tarda\u003csub\u003eW\u003c/sub\u003e with a maximum near 90\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed). Below ~\u0026thinsp;200\u0026deg;C, there is little evidence from the MSEGA data for evolution of organic compounds. For example, significant signals for m/z\u0026thinsp;=\u0026thinsp;15 (CH\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e, methyl derivatives) and 26 (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e from aromatic hydrocarbons) are absent at this low temperature range (Fig. S15). However, the signal for m/z\u0026thinsp;=\u0026thinsp;30 shows two maxima below 300\u0026deg;C at 100\u0026deg;C and 200\u0026deg;C for Tarda\u003csub\u003eW\u003c/sub\u003e, whereas Tarda\u003csub\u003eN\u003c/sub\u003e only shows a weak maximum at 200\u0026deg;C (Fig. S16). This peak can have several origins, including CH\u003csub\u003e2\u003c/sub\u003eO\u003csup\u003e+\u003c/sup\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe mass loss for Tarda\u003csub\u003eW\u003c/sub\u003e below 200\u0026deg;C of 3.01 wt% is at the lower end for the two published values of 3.7 and 7 wt% \u003csup\u003e45,46\u003c/sup\u003e. This mass-loss range is typical for smectite-rich type 1 meteorites of ~\u0026thinsp;5 to ~\u0026thinsp;10 wt% \u003csup\u003e19,20,30,44\u003c/sup\u003e. However, samples dried under flowing He for 24 hr show a mass loss of 1.011 wt% (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea, S11), whereas the artificially weathered sample has a mass loss of 3.013 wt % after being dried under laboratory conditions with ~\u0026thinsp;35% RH (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea, S12). The data for Tarda suggests that the quantity of molecular water intercalated with the clays prior to arrival on Earth is minor. This result is corroborated by the low mass loss of ~\u0026thinsp;0.6 wt% below 200\u0026deg;C for the mineralogically similar samples from asteroid Ryugu \u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003cb\u003eMineralogical and physical effects of high surface area.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe high S\u003csub\u003eBET\u003c/sub\u003e of the clay-rich meteorites as well as the nanoscale interconnected porosity allows atmospheric water vapor to impinge upon the bulk of the matrix mineral network. In addition, the terrestrial alteration of Tarda and the CI chondrites is accentuated by the ability of their abundant matrix smectite to intercalate water \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e,\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e. While the S\u003csub\u003eBET\u003c/sub\u003e derived from N\u003csub\u003e2\u003c/sub\u003e BET gives a measure of the N\u003csub\u003e2\u003c/sub\u003e accessible surface area, this gas does not probe the interlayer adsorption sites of the smectite. For example, the surface area of Orgueil measured by the BET using N\u003csub\u003e2\u003c/sub\u003e is 30.2 m\u003csup\u003e2\u003c/sup\u003e/g and 165.8 m\u003csup\u003e2\u003c/sup\u003e/g using H\u003csub\u003e2\u003c/sub\u003eO \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. Water intercalates around the interlayer cations between stacked 2:1 layers of the smectite clays. The intercalation of water by the smectite group minerals has been extensively studied \u003csup\u003e\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e,\u003cspan additionalcitationids=\"CR49 CR50 CR51 CR52\" citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e. The degree of intercalation is dependent on the elemental properties of the clay, in particular the type of interlayer cation, and p/p\u003csup\u003e0\u003c/sup\u003e of the surrounding water vapor \u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e. Increasing p/p\u003csup\u003e0\u003c/sup\u003e causes interlayer adsorption with a stepwise increase in the d\u003csub\u003e001\u003c/sub\u003e spacing of smectite. For example, the d\u003csub\u003e001\u003c/sub\u003e of Ca montmorillonite increases from 9.6\u0026ndash;10.7 \u0026Aring; for the fully dehydrated form, to 11.8\u0026ndash;12.9 \u0026Aring;, 14.5\u0026ndash;15.8 \u0026Aring;, to 18.0-19.5 \u0026Aring;, for the mono-, bi- and tri-hydrate, respectively \u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e,\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. In contrast, the serpentine 001 reflection from Aguas Zarcas and Murchison is not affected by the water uptake.\u003c/p\u003e \u003cp\u003eThe smectite d\u003csub\u003e001\u003c/sub\u003e spacing for Tarda shows similar behaviors with respect to p/p\u003csup\u003e0\u003c/sup\u003e, increasing from 10.9 \u0026Aring; at 0% RH to 15.1 \u0026Aring; at 100% RH (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). However, the extreme breadth of the smectite d\u003csub\u003e001\u003c/sub\u003e spacing strongly suggests material that is on average fine grained, poorly crystalline, with turbostratic stacking, interstratified, or a combination thereof \u003csup\u003e\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e,\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u003c/sup\u003e. This disorder is particularly evident for Tarda heated to 300\u0026deg;C corresponding to the fully dehydrated form and shows an exceptionally broad d\u003csub\u003e001\u003c/sub\u003e basal spacing spread over ~\u0026thinsp;5 \u0026deg;2θ Cu\u003cem\u003eK\u003c/em\u003eα. In contrast, well crystallized smectite shows a sharp d\u003csub\u003e001\u003c/sub\u003e for the different hydration states, e.g., \u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. The broadness of the Tarda smectite d\u003csub\u003e001\u003c/sub\u003e peak may also arise from materials intercalated between the 2:1 layers, similar to the carbonaceous material intercalated between the smectite 2:1 layers in Orgueil \u003csup\u003e\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u003c/sup\u003e. This intercalated material prevents the 2:1 smectite layers from collapsing and forming a narrow d\u003csub\u003e001\u003c/sub\u003e spacing.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFragments of Tarda swell and crack under high humidity and cycles of higher and lower humidity cause spalling of the fragments (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, S17). This cracking is also accompanied by the growth of gypsum on the fragments within a few days under high relative humidity. Gypsum growth is instituated by the high surface area that forms the interconnected nanoporous sponge-like network of nano-sized pathways. The rapidity of gypsum formation was evident from the powder XRD, which show a prominent gypsum 020 reflection after only 12 hr at 100% RH (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). The formation of the gypsum is an irreversible mineralogical change that increases the mass of the sample and decreases the surface area. For example, the S\u003csub\u003eBET\u003c/sub\u003e of the gypsum-rich Tarda (Tarda\u003csup\u003eg\u003c/sup\u003e) was significantly lower than Tarda-100 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTarda shows an extreme example of terrestrial alteration by rapidly slaking in water (Supplementary Movie1) and other polar liquids. Slaking is a commonly shown by many clay-rich soils \u003csup\u003e\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u003c/sup\u003e. From a practical point of view this slaking is problematic as many laboratory sample preparation techniques, such as cutting, grinding, and polishing use polar liquids, most commonly water, ethylene glycol, alcohols, or acetone as a lubricant. This behavior is not unique to Tarda. For example, in 1834 Berzelius said that in the presence of water the CI1 chondrite Alais \u0026ldquo;... zerf\u0026auml;llt er nach einigen Augenblicken su einem graugr\u0026uuml;nen Brei ... .\u0026rdquo; \u003csup\u003e\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e\u003c/sup\u003e. This extreme reaction to polar liquids has implications for curation as well as sample preparation for analytical studies. The propensity of the smectite-rich meteorites, and to a certain degree those that are serpentine-rich, to disintegrate using polar liquids requires alternative cutting and polishing methods. In particular, cutting and grinding down to 1200 grit size is done dry and without the use of any liquids. Final polishing is achieved with mineral oil and diamond that is then washed with a non-polar solvent, such as toluene.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe N\u003csub\u003e2\u003c/sub\u003e BET analysis of the clay-rich meteorites reveals scale-dependent aspects of their interiors: their high surface areas, indicative of nano-scale porosity, and the ease with which adsorption sites become blocked by atmospheric gases, including during curation in an N\u003csub\u003e2\u003c/sub\u003e atmosphere. The N\u003csub\u003e2\u003c/sub\u003e accessible high surface areas, formed by the interconnected mesoporosity, constitutes a sponge-like network with nano-sized pathways for water vapor in the atmosphere to impinge upon and intercalate smectite throughout the bulk of the material. The S\u003csub\u003eBET\u003c/sub\u003e of 81.61 m\u003csup\u003e2\u003c/sup\u003e/g for Tarda-250, although higher than many terrestrial clays, may still be lower than its S\u003csub\u003eBET\u003c/sub\u003e prior to entering the Earth\u0026rsquo;s atmosphere, because nano-scale porosity is so rapidly blocked and modified during terrestrial residence. We demonstrated this blocking effect by subjecting Tarda to 100% RH at 32\u0026deg;C for 24 hours. We find that S\u003csub\u003eBET\u003c/sub\u003e is significantly reduced by blocking, accompanied by the growth of abundant gypsum on and within the fragments. Furthermore, the surface area adsorption capacity of smectite-rich meteorites will be significantly higher than the S\u003csub\u003eBET\u003c/sub\u003e determined with N\u003csub\u003e2\u003c/sub\u003e BET, as this gas does not probe the interlayer regions around the cations between the 2:1 layers of the clay.\u003c/p\u003e \u003cp\u003eFrom a practical point of view, the rate and ease with which these clay-rich astromaterials adsorb atmospheric gases, but not limited to H\u003csub\u003e2\u003c/sub\u003eO, implores the need for curation in a stable atmosphere with constant low relative humidity to preserve their indigenous physical and chemical properties. The revelation that smectite and serpentine-rich astromaterials possess an intrinsic high-surface area with a nanoporous network also has implications for other physical properties including sound speed, thermal conductivity, and compressive strength which depend on the structural distribution within the material. These astromaterial properties govern, for instance, the resistance of boulders on the surface of an asteroid to hypervelocity impacts and to thermal cycling on their parent body. They also govern how, and how deep, a meteor comes apart during atmospheric entry. The measurement of porosity is probably the easiest way of probing the nano-scale structure of astromaterial, complementary to measurements of crush-curves and other failure mechanisms.\u003c/p\u003e \u003cp\u003eThe high surface area of Tarda, and the ease with which S\u003csub\u003eBET\u003c/sub\u003e is reduced by 24-hr duration at high humidity, may explain the significantly lower surface area obtained for the mineralogically-similar meteorites Ivuna and Orgueil. Ivuna and Orgueil have had relatively long residence times on Earth, i.e., 1938 and 1864, respectively, which led to the formation of pore-blocking secondary minerals. In contrast, Tarda fell in southern Morocco on the 25th of August 2020, and the specimens studied here were rapidly collected and since curated under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere in BCMS. We therefore speculate that the recently returned asteroid samples from Ryugu and Bennu, which have mineralogical and structural similarities to Tarda, will also show a similarly high surface area and fine-scale, interconnected nanoporosity subject to blocking.\u003c/p\u003e"},{"header":"Experimental section","content":"\u003cp\u003e\u003cstrong\u003eMeteorites and curatorial conditions.\u0026nbsp;\u003c/strong\u003eAll the meteorites studied here are curated under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere in the Carleton B Moore Meteorite Collection in the Buseck Center for Meteorite Studies (BCMS) at Arizona State University (ASU). The following samples were studied – Tarda (ASU#2149), Ivuna (ASU#856), Orgueil (ASU#222), Aguas Zarcas (ASU#2121), Murchison (ASU#828), and Allende (ASU#818). Aguas Zarcas fell in Costa Rica on the 23\u003csup\u003erd\u003c/sup\u003e of April 2019. Sample were collected and returned to the BCMS by Michael Farmer within one week of the fall and curated under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere. Tarda fell in southern Morocco on the 25\u003csup\u003eth\u003c/sup\u003e of August 2020 and sample were curated under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere in BCMS by September of 2020. Neither Aguas Zarcas nor the Tarda samples received by BCMS saw significant moisture, other than atmospheric air, before curation under the dry N\u003csub\u003e2\u003c/sub\u003e atmosphere. In addition, selected comparative measurements were undertaken on Murchison (CM2) and Ivuna (CI1). Murchison fell over Murchison, Australia on the 28\u003csup\u003eth\u003c/sup\u003e of September 1969 and Ivuna fell near the western shore of Lake Rukwa in Tanzania on 16\u003csup\u003eth\u003c/sup\u003e December 1938. Humidity in air near 0% was achieved by placing the samples in a bell jar which contained an open container of the drying agent P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e. Laboratory temperature and humidity were measured with a Onset HOBO® U12 datalogger.\u0026nbsp; Relative humidity of 100% was achieved by placing the sample in a sealed container containing water. Sample masses were measured with a Mettler Toleda AR201 analytical balance with a repeatability (sd) of 0.04 mg and readability of 0.01 mg.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBET N\u003csub\u003e2\u003c/sub\u003e analysis.\u003c/strong\u003e Adsorption/desorption isotherms were measured under N\u003csub\u003e2\u003c/sub\u003e at -195.8 °C on a Micromeritics® TriStar II Plus surface area and porosity analyzer.\u0026nbsp;The meteorites were characterized by applying the BET N\u003csub\u003e2\u003c/sub\u003e sorption method. Data was analyzed using the t-Plot method assuming a Harkins and Jura thickness equation and BJH analyses with Halsey-Faas correction to derive the pore data. Measurements were made on Tarda (C2-ung), Ivuna (CI1), Orgueil (CI1), Aguas Zarcas (CM2), Murchison (CM2), and for comparison the anhydrous carbonaceous chondrite Allende (CV). Sample sizes for the BET measurements were on the order of 0.5 to 0.8 g. Samples were run as mm-sized fragments and some as powders.\u0026nbsp;In this paper, the outgassing pretreatment is listed after the meteorite name: Tarda-100 refers to the sample outgassed at 100 °C under flowing N\u003csub\u003e2\u003c/sub\u003e for 24 hr; after prolonged storage under a dry N\u003csub\u003e2\u003c/sub\u003e atmosphere (-NH); after being held under a vacuum for 24 hr at room temperature (-VRT); and, after heating in the presence of flowing dry nitrogen at 250 °C for 24 hr (-250). The BET measurements were acquired over the relative pressure range p/p\u003csup\u003e0\u003c/sup\u003e (p is the actual gas pressure and p\u003csup\u003e0\u003c/sup\u003e is the vapor pressure of the adsorbing gas) of 0 to 0.99, which corresponds to the absolute pressure of ~0.8 to 730 mmHg. A value of 0.1620 nm\u003csup\u003e2\u003c/sup\u003e was used as the molecular cross section area for N\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePowder X-ray diffraction.\u003c/strong\u003e Powder XRD patterns were acquired with a Rigaku MiniFlex 600 diffractometer. This diffractometer is operated with Cu\u003cem\u003eK\u003c/em\u003e\u003cem\u003ea\u003c/em\u003e radiation and is equipped with a post-diffraction graphite monochromator and automatic divergence slit system. Data were acquired from 2° to 65° 2q\u0026nbsp;at 0.02° steps, and 30 to 60 s/step. XRD samples were prepared from an ~1- to 2-mm-sized fragment, which weighed ~10 mg. The chips were crushed and lightly ground to a fine powder and mixed with a few milliliters of dry methanol. The resulting slurry was pipetted and spread into a thin, smooth film on a low-background, single-crystal, quartz plate. This slurry was dried rapidly (~5 s) under flowing warm air forming a thin film. Selected prepared XRD slides were subjected to standard clay mineral treatments (Moore and Reynolds 1989) prior to X-ray data acquisition, viz., ethylene glycol vapor at 60° C for 24 hr and heating to 300° C under air for 1 hr.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTG-DTA/DSC.\u0026nbsp;\u003c/strong\u003eThermal measurements were performed on a Setaram LabsysEvo (Lyon, France) TG-DTA/DSC system, in flowing (60 mL/min) purging gas atmosphere [99.9999% purity He /DTA/, 99.999% purity Ar /DSC/ and 99.999% purity synthetic air (20% O\u003csub\u003e2\u003c/sub\u003e in N\u003csub\u003e2\u003c/sub\u003e) /DSC/ atmospheres]. The sample was weighed into a 100 μL Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e crucible (the reference crucible was empty) and heated from 25 to 1000 °C with a heating rate of 10 °C/min. The obtained data was baseline corrected and further processed with the thermoanalyzer’s processing software (Calisto Processing, ver. 2.092). The thermal analyzer (both the temperature scale and calorimetric sensitivity) was calibrated by a multipoint calibration method, in which seven different certified reference materials (CRM’s) were used to cover the thermal analyzer’s entire operating temperature range.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTG-DSC-MSEGA.\u0026nbsp;\u003c/strong\u003eThermal measurements were performed on a Setaram LabsysEvo (Lyon, France) TG-DSC system, in flowing (90 mL/min) helium gas (99.9999% purity) atmosphere. The sample was weighed directly into a 100 μL Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e crucible (the reference cell was empty) and was heated from 25 to 1000 °C with a heating rate of 20 °C/min. The obtained data was baseline corrected and further processed with the thermoanalyzer’s processing software (Calisto Processing, ver. 2.092). The thermal analyzer (both the temperature scale and calorimetric sensitivity) was calibrated by a multipoint calibration method, in which seven different certified reference materials (CRM’s) were used to cover the thermal analyzer’s entire operating temperature range. In parallel with the thermal measurements, the analysis of evolved gases/volatiles was performed on a Pfeiffer Vacuum Omni Star™ mass spectrometric evolved gas analysis system (MS-EGA), which was connected to the above-mentioned thermal analyzer. The gas splitter was thermostated to 230 °C, while the transfer line to the mass spectrometer was thermostated to 220 °C. The temperature of the mass spectrometer gas inlet was programmed to 120 °C. The measurements were done in SEM Bargraph Cycles acquisition mode, where the m/z interval of 11-130 was continuously scanned with a speed of 50 ms/amu. The spectrometer was operated in electron impact mode.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTarda artificial weathering.\u0026nbsp;\u003c/strong\u003eApproximately 33 mg of dried, as received, Tarda powder was mixed with 100 mL of ultrapure water and allowed to evaporate to dryness. TG-DSC-MSEGA data were acquired from the dried powder.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was made possible through the generosity of the Boudreaux Family Foundation for the donation of the Tarda samples and to Michael Farmer and Carleton Moore who donated pristine samples of Aguas Zarcas to the Buseck Center for Meteorite studies. The authors are grateful for the support for this research provided by the NASA YORPD program through grant 80NSSC22K0238. L.G. is grateful to Prof. James Bell for the use of the powder x-ray diffractometer in the Planetary Space Extreme Environments Laboratory at Arizona State University, and to Dr Sarah McGregor and Mr. Anthony (A.J.) Woolson for acquiring the BET data in the METAL Core of the Eyring Materials Center at ASU.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eKuila, U. \u0026amp; Prasad, M. Specific surface area and pore‐size distribution in clays and shales. \u003cem\u003eGeophys. Prospect.\u003c/em\u003e \u003cstrong\u003e61\u003c/strong\u003e, 341-362 (2013). \u003c/li\u003e\n\u003cli\u003eWigger, C., Gimmi, T., Muller, A. \u0026amp; Van Loon, L. R. The influence of small pores on the anion transport properties of natural argillaceous rocks\u0026ndash;A pore size distribution investigation of Opalinus Clay and Helvetic Marl. \u003cem\u003eAppl. Clay Sci.\u003c/em\u003e \u003cstrong\u003e156\u003c/strong\u003e, 134-143 (2018). \u003c/li\u003e\n\u003cli\u003eConsolmagno, G. J., Britt, D. T. \u0026amp; Macke, R. J. The significance of meteorite density and porosity. \u003cem\u003eChem. Erde\u003c/em\u003e \u003cstrong\u003e68\u003c/strong\u003e, 1-29 (2008). \u003c/li\u003e\n\u003cli\u003eFlynn, G. J., Moore, L. B. \u0026amp; Kl\u0026ouml;ck, W. Density and porosity of stone meteorites: Implications for the density, porosity, cratering, and collisional disruption of asteroids. \u003cem\u003eIcarus\u003c/em\u003e \u003cstrong\u003e142\u003c/strong\u003e, 97-105 (1999). \u003c/li\u003e\n\u003cli\u003eFlynn, G. J., Consolmagno, G. J., Brown, P. \u0026amp; Macke, R. J. Physical properties of the stone meteorites: Implications for the properties of their parent bodies. \u003cem\u003eChem. Erde\u003c/em\u003e \u003cstrong\u003e78\u003c/strong\u003e, 269-298 (2018). \u003c/li\u003e\n\u003cli\u003eMacke, R. J., Consolmagno, G. J. \u0026amp; Britt, D. T. Density, porosity, and magnetic susceptibility of carbonaceous chondrites. \u003cem\u003eMeteorit. Planet. Sci.\u003c/em\u003e \u003cstrong\u003e46\u003c/strong\u003e, 1842-1862 (2011). \u003c/li\u003e\n\u003cli\u003eBland, P. A.\u003cem\u003e et al.\u003c/em\u003e Why aqueous alteration in asteroids was isochemical: High porosity\u0026ne; high permeability. \u003cem\u003eEarth Planet. Sci. Lett.\u003c/em\u003e \u003cstrong\u003e287\u003c/strong\u003e, 559-568 (2009). \u003c/li\u003e\n\u003cli\u003eHuang, B., Bartholomew, C. H. \u0026amp; Woodfield, B. F. Improved calculations of pore size distribution for relatively large, irregular slit-shaped mesopore structure. \u003cem\u003eMicroporous Mesoporous Mater.\u003c/em\u003e \u003cstrong\u003e184\u003c/strong\u003e, 112-121 (2014). \u003c/li\u003e\n\u003cli\u003eLanders, J., Gor, G. Y. \u0026amp; Neimark, A. V. Density functional theory methods for characterization of porous materials. \u003cem\u003eColloids Surf. A\u003c/em\u003e \u003cstrong\u003e437\u003c/strong\u003e, 3-32 (2013). \u003c/li\u003e\n\u003cli\u003eThommes, M. \u0026amp; Cychosz, K. A. Physical adsorption characterization of nanoporous materials: progress and challenges. \u003cem\u003eAdsorption\u003c/em\u003e \u003cstrong\u003e20\u003c/strong\u003e, 233-250 (2014). \u003c/li\u003e\n\u003cli\u003eThommes, M.\u003cem\u003e et al.\u003c/em\u003e Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). \u003cem\u003ePure Appl. Chem.\u003c/em\u003e \u003cstrong\u003e87\u003c/strong\u003e, 1051-1069 (2015). \u003c/li\u003e\n\u003cli\u003eBrunauer, S., Emmett, P. H. \u0026amp; Teller, E. Adsorption of gases in multimolecular layers. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e60\u003c/strong\u003e, 309-319 (1938). \u003c/li\u003e\n\u003cli\u003eSing, K. The use of nitrogen adsorption for the characterisation of porous materials. \u003cem\u003eColloids Surf. A\u003c/em\u003e \u003cstrong\u003e187\u003c/strong\u003e, 3-9 (2001). \u003c/li\u003e\n\u003cli\u003eSing, K. S. W. Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984). \u003cem\u003ePure Appl. Chem.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 603-619 (1985). \u003c/li\u003e\n\u003cli\u003eDogan, A. U.\u003cem\u003e et al.\u003c/em\u003e Baseline studies of the clay minerals society source clays: specific surface area by the Brunauer Emmett Teller (BET) method. \u003cem\u003eClays Clay Miner.\u003c/em\u003e \u003cstrong\u003e54\u003c/strong\u003e, 62-66 (2006). \u003c/li\u003e\n\u003cli\u003eLiu, K. \u0026amp; Ostadhassan, M. The impact of pore size distribution data presentation format on pore structure interpretation of shales. \u003cem\u003eAdv.Geo-Energy Res.\u003c/em\u003e \u003cstrong\u003e3\u003c/strong\u003e, 187-197 (2019). \u003c/li\u003e\n\u003cli\u003eMastalerz, M., Hampton, L., Drobniak, A. \u0026amp; Loope, H. Significance of analytical particle size in low-pressure N\u003csub\u003e2\u003c/sub\u003e and CO\u003csub\u003e2\u003c/sub\u003e adsorption of coal and shale. \u003cem\u003eInt. J Coal Geol.\u003c/em\u003e \u003cstrong\u003e178\u003c/strong\u003e, 122-131 (2017). \u003c/li\u003e\n\u003cli\u003eYuan, Y.\u003cem\u003e et al.\u003c/em\u003e Compositional controls on nanopore structure in different shale lithofacies: A comparison with pure clays and isolated kerogens. \u003cem\u003eFuel\u003c/em\u003e \u003cstrong\u003e303\u003c/strong\u003e, 121079 (2021). \u003c/li\u003e\n\u003cli\u003eFanale, F. P. \u0026amp; Cannon, W. A. Surface properties of the Orgueil meteorite: implications for the early history of solar system volatiles. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e38\u003c/strong\u003e, 453-470 (1974). \u003c/li\u003e\n\u003cli\u003eJ\u0026auml;nchen, J., Feist, M. \u0026amp; M\u0026ouml;hlmann, D. T. F. Adsorption and thermoanalytical studies on the CI chondrite Orgueil as case of early preplanetary matter. \u003cem\u003eThermochim. Acta\u003c/em\u003e \u003cstrong\u003e614\u003c/strong\u003e, 177-184 (2015). https://doi.org:10.1016/j.tca.2015.06.025\u003c/li\u003e\n\u003cli\u003eMautner, M. N. Formation, chemistry and fertility of extraterrestrial soils: cohesion, water adsorption and surface area of carbonaceous chondrite. Prebiotic and space resource applications. \u003cem\u003eIcarus\u003c/em\u003e \u003cstrong\u003e137\u003c/strong\u003e, 178-195 (1999). \u003c/li\u003e\n\u003cli\u003eLauretta, D. S.\u003cem\u003e et al.\u003c/em\u003e OSIRIS-REx: Sample Return from Asteroid (101955) Bennu. \u003cem\u003eSpace Sci. Rev.\u003c/em\u003e \u003cstrong\u003e212\u003c/strong\u003e, 925-984 (2017). https://doi.org:10.1007/s11214-017-0405-1\u003c/li\u003e\n\u003cli\u003eChesley, S. R.\u003cem\u003e et al.\u003c/em\u003e Orbit and bulk density of the OSIRIS-REx target Asteroid (101955) Bennu. \u003cem\u003eIcarus\u003c/em\u003e \u003cstrong\u003e235\u003c/strong\u003e, 5-22 (2014). \u003c/li\u003e\n\u003cli\u003eNakamura, E.\u003cem\u003e et al.\u003c/em\u003e On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective. \u003cem\u003eProc. Jpn Acad., Series B\u003c/em\u003e \u003cstrong\u003e98\u003c/strong\u003e, 227-282 (2022). https://doi.org:10.2183/pjab.98.015\u003c/li\u003e\n\u003cli\u003eYokoyama, T.\u003cem\u003e et al.\u003c/em\u003e Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e379\u003c/strong\u003e, 1-10 (2023). https://doi.org:doi:10.1126/science.abn7850\u003c/li\u003e\n\u003cli\u003eFuchs, L. H., Olsen, E. \u0026amp; Jensen, K. J. Mineralogy, mineral-chemistry, and composition of the Murchison (C2) meteorite. \u003cem\u003eSmithson. Contrib. Earth Sci.\u003c/em\u003e \u003cstrong\u003e10\u003c/strong\u003e, 39 (1973). \u003c/li\u003e\n\u003cli\u003eGarvie, L. A. J. Mineralogy of the 2019 Aguas Zarcas (CM2) carbonaceous chondrite meteorite fall. \u003cem\u003eAm. Min.\u003c/em\u003e \u003cstrong\u003e106\u003c/strong\u003e, 1900-1916 (2021). \u003c/li\u003e\n\u003cli\u003eHoward, K. T., Alexander, C. M. O. D., Schrader, D. L. \u0026amp; Dyl, K. A. Classification of hydrous meteorites (CR, CM and C2 ungrouped) by phyllosilicate fraction: PSD-XRD modal mineralogy and planetesimal environments. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e149\u003c/strong\u003e, 206-222 (2015). \u003c/li\u003e\n\u003cli\u003eKing, A. J., Schofield, P. F., Howard, K. T. \u0026amp; Russell, S. S. Modal mineralogy of CI and CI-like chondrites by X-ray diffraction. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e165\u003c/strong\u003e, 148-160 (2015). https://doi.org:10.1016/j.gca.2015.05.038\u003c/li\u003e\n\u003cli\u003eKing, A. J., Solomon, J. R., Schofield, P. F. \u0026amp; Russell, S. S. Characterising the CI and CI-like carbonaceous chondrites using thermogravimetric analysis and infrared spectroscopy. \u003cem\u003eEarth, Planets and Space\u003c/em\u003e \u003cstrong\u003e67\u003c/strong\u003e, 1-12 (2015). \u003c/li\u003e\n\u003cli\u003eSuttle, M. D., King, A. J., Schofield, P. F., Bates, H. C. \u0026amp; Russell, S. S. The aqueous alteration of CM chondrites, a review. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e299\u003c/strong\u003e, 219-256 (2021). \u003c/li\u003e\n\u003cli\u003eTomeoka, K. \u0026amp; Buseck, P. R. Matrix mineralogy of the Orgueil CI carbonaceous chondrtie. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e52\u003c/strong\u003e, 1627-1640 (1988). https://doi.org:10.1016/0016-7037(88)90231-1\u003c/li\u003e\n\u003cli\u003eGarvie, L. A. J. in \u003cem\u003e49th Annual Lunar and Planetary Science Conference.\u003c/em\u003e 2085.\u003c/li\u003e\n\u003cli\u003eGarvie, L. A. J. \u0026amp; Trif, L. in \u003cem\u003e52nd Lunar and Planetary Science Conference.\u003c/em\u003e 2446.\u003c/li\u003e\n\u003cli\u003eGarvie, L. A. J. in \u003cem\u003e54th Lunar and Planetary Science Conference\u003c/em\u003e Abstract #2274 (Lunar and Planetary Institute, Houston, 2023).\u003c/li\u003e\n\u003cli\u003eElmaleh, A.\u003cem\u003e et al.\u003c/em\u003e Formation and transformations of Fe-rich serpentines by asteroidal aqueous alteration processes: A nanoscale study of the Murray chondrite. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e158\u003c/strong\u003e, 162-178 (2015). \u003c/li\u003e\n\u003cli\u003eLee, M. R., Lindgren, P. \u0026amp; Sofe, M. R. Aragonite, breunnerite, calcite and dolomite in the CM carbonaceous chondrites: High fidelity recorders of progressive parent body aqueous alteration. \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e144\u003c/strong\u003e, 126-156 (2014). \u003c/li\u003e\n\u003cli\u003eBarrer, R. M. \u0026amp; MacLeod, D. M. Intercalation and sorption by montmorillonite. \u003cem\u003eTrans. Faraday Soc.\u003c/em\u003e \u003cstrong\u003e50\u003c/strong\u003e, 980-989 (1954). \u003c/li\u003e\n\u003cli\u003eQuirk, J. P. \u0026amp; Aylmore, L. A. G. Domains and quasi‐crystalline regions in clay systems. \u003cem\u003eSoil Sci. Soc. Am. J.\u003c/em\u003e \u003cstrong\u003e35\u003c/strong\u003e, 652-654 (1971). \u003c/li\u003e\n\u003cli\u003eMackinnon, I. D. R. in \u003cem\u003e11th Lunar and Planetary Science Conference.\u003c/em\u003e 839-852 (Pergamon Press).\u003c/li\u003e\n\u003cli\u003eTomeoka, K., McSween Jr, H. Y. \u0026amp; Buseck, P. R. in \u003cem\u003eProceedings of the NIPR Symposium on Antarctic Meteorites.\u003c/em\u003e 221-234.\u003c/li\u003e\n\u003cli\u003eZega, T. J., Garvie, L. A. J., D\u0026oacute;dony, I. \u0026amp; Buseck, P. R. Serpentine nanotubes in the Mighei CM chondrite. \u003cem\u003eEarth Planet. Lett.\u003c/em\u003e \u003cstrong\u003e223\u003c/strong\u003e, 141-146 (2004). \u003c/li\u003e\n\u003cli\u003eZega, T. J.\u003cem\u003e et al.\u003c/em\u003e Polyhedral serpentine grains in CM chondrites. \u003cem\u003eMeteoritics \u0026amp; Planetary Science\u003c/em\u003e \u003cstrong\u003e41\u003c/strong\u003e, 681-688 (2006). \u003c/li\u003e\n\u003cli\u003eGarenne, A.\u003cem\u003e et al.\u003c/em\u003e The abundance and stability of \u0026ldquo;water\u0026rdquo; in type 1 and 2 carbonaceous chondrites (CI, CM and CR). \u003cem\u003eGeochim. Cosmochim. Acta\u003c/em\u003e \u003cstrong\u003e137\u003c/strong\u003e, 93-112 (2014). \u003c/li\u003e\n\u003cli\u003eKing, A. J., Bates, H. C., Schofield, P. F. \u0026amp; Russell, S. S. in \u003cem\u003e52nd Lunar and Planetary Science Conference.\u003c/em\u003e 1909.\u003c/li\u003e\n\u003cli\u003eYesiltas, M.\u003cem\u003e et al.\u003c/em\u003e Compositional and spectroscopic investigation of three ungrouped carbonaceous chondrites. \u003cem\u003eMeteor. Planet. Sci.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 1665-1687 (2022). \u003c/li\u003e\n\u003cli\u003eYokoyama, T.\u003cem\u003e et al.\u003c/em\u003e Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e379\u003c/strong\u003e, eabn7850 (2022). \u003c/li\u003e\n\u003cli\u003eMacEwan, D. M. C. \u0026amp; Wilson, M. J. in \u003cem\u003eCrystal Structures of Clay Minerals and their X-ray Identification\u003c/em\u003e (eds G.W. Brindley \u0026amp; G. Brown) 197-248 (Mineralogical Society, 1980).\u003c/li\u003e\n\u003cli\u003eEmerson, W. W. The swelling of Ca‐montmorillonite due to water absorption: I. Water uptake in the vapour phase. \u003cem\u003eJ. Soil Sci.\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, 31-39 (1962). \u003c/li\u003e\n\u003cli\u003eEmerson, W. W. The swelling of Ca-montmorillonite due to water adsorption 2. Water uptake in the liquid phase. \u003cem\u003eJ. Soil Sci.\u003c/em\u003e \u003cstrong\u003e13\u003c/strong\u003e, 40-45 (1962). \u003c/li\u003e\n\u003cli\u003eFerrage, E. Investigation of the interlayer organization of water and ions in smectite from the combined use of diffraction experiments and molecular simulations. A review of methodology, applications, and perspectives. \u003cem\u003eClays Clay Miner.\u003c/em\u003e \u003cstrong\u003e64\u003c/strong\u003e, 348-373 (2016). \u003c/li\u003e\n\u003cli\u003eHatch, C. D.\u003cem\u003e et al.\u003c/em\u003e Water adsorption on clay minerals as a function of relative humidity: application of BET and Freundlich adsorption models. \u003cem\u003eLangmuir\u003c/em\u003e \u003cstrong\u003e28\u003c/strong\u003e, 1790-1803 (2012). \u003c/li\u003e\n\u003cli\u003eHofmann, U. \u0026amp; Bilke, W. \u0026Uuml;ber die Innerkristalline Quellung und das Basenaustauschverm\u0026ouml;gen des Montmorillonits. \u003cem\u003eKolloid-Zeitschrift\u003c/em\u003e \u003cstrong\u003e77\u003c/strong\u003e, 238-251 (1936). \u003c/li\u003e\n\u003cli\u003eBrindley, G. W. in \u003cem\u003eCrystal Structures of Clay Minerals and their X-ray Identification\u003c/em\u003e (eds G.W. Brindley \u0026amp; G. Brown) 125-196 (Mineralogical Society, 1980).\u003c/li\u003e\n\u003cli\u003eReynolds, R. C. in \u003cem\u003eCrystal Structures of Clay Minerals and their X-ray Identification\u003c/em\u003e (eds G.W. Brindley \u0026amp; G. Brown) 249-304 (Mineralogical Society, 1980).\u003c/li\u003e\n\u003cli\u003eGarvie, L. A. J. \u0026amp; Buseck, P. R. Prebiotic carbon in clays from Orgueil and Ivuna (CI), and Tagish Lake (C2 ungrouped) meteorites. \u003cem\u003eMeteor. Planet. Sci.\u003c/em\u003e \u003cstrong\u003e42\u003c/strong\u003e, 2111-2117 (2007). \u003c/li\u003e\n\u003cli\u003eEmerson, W. W. The slaking of soil crumbs as influenced by clay mineral composition. \u003cem\u003eAust. J. Soil Res.\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 211-217 (1964). \u003c/li\u003e\n\u003cli\u003eBerzelius, J. J. Ueber Meteorsteine. IV Meteorstein von Alais. \u003cem\u003eAnn. Phys. Chem.\u003c/em\u003e \u003cstrong\u003e33\u003c/strong\u003e, 113-148 (1834). \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3854166/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3854166/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSeveral important processes, from meteor disruption in Earth\u0026rsquo;s atmosphere and impact with the ground, to the comminution of boulders by thermal and impact processes and slope mechanics on the surface of an asteroid, to access and utilization of in-situ resources, depend on astromaterial properties including porosity, sound speed, thermal conductivity, and compressive strength. Whereas the bulk porosity of clay-rich meteorites is well established, the magnitude of their surface area and nano-scale porosity is poorly known. Here we apply the N\u003csub\u003e2\u003c/sub\u003e BET gas adsorption method to measure the scale-distribution and net surface area of porosity in a range of clay-rich meteorites. Tarda (C2-ung) has high surface area, up to 82 m\u003csup\u003e2\u003c/sup\u003e/g, dominated by an interconnected network of ~\u0026thinsp;3-nm-sized pores. In comparison, Ivuna and Orgueil (CI1) and Aguas Zarcas and Murchison (CM2) have bimodal nanopore-size distributions with a lower density of ~\u0026thinsp;3-nm pores and broader size distributions around 40 nm, and corresponding lower surface areas\u0026thinsp;~\u0026thinsp;14\u0026ndash;19 m\u003csup\u003e2\u003c/sup\u003e/g. The high-surface-area of Tarda may indicate a high density of intra-tachoid pores among and between the nano-sized aggregates of poorly ordered clays. Samples from asteroids Ryugu and Bennu, mineralogically and texturally similar to Tarda, may have similarly interconnected nano-scale porosity with high surface area.\u003c/p\u003e","manuscriptTitle":"High surface area and interconnected nanoporosity of clay-rich astromaterials","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-22 14:04:20","doi":"10.21203/rs.3.rs-3854166/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-02-17T03:50:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-01-23T17:27:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"17befecd-a60e-44d0-9c93-8d9665a4e069","date":"2024-01-21T20:33:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-01-21T20:13:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-01-21T14:36:33+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-01-21T04:13:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-01-21T04:11:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-01-11T16:49:17+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3867c96b-1247-43c1-87d4-c84f440d130c","owner":[],"postedDate":"January 22nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":28277142,"name":"Earth and environmental sciences/Planetary science"},{"id":28277143,"name":"Physical sciences/Astronomy and planetary science"},{"id":28277144,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2024-05-09T17:01:39+00:00","versionOfRecord":{"articleIdentity":"rs-3854166","link":"https://doi.org/10.1038/s41598-024-61114-2","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-05-06 17:01:38","publishedOnDateReadable":"May 6th, 2024"},"versionCreatedAt":"2024-01-22 14:04:20","video":"","vorDoi":"10.1038/s41598-024-61114-2","vorDoiUrl":"https://doi.org/10.1038/s41598-024-61114-2","workflowStages":[]},"version":"v1","identity":"rs-3854166","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3854166","identity":"rs-3854166","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}