Thin Section Microfossil Analysis: Unlocking Paleoenvironmental Secrets of the Romualdo Formation, Araripe Basin

Thin Section Microfossil Analysis: Unlocking Paleoenvironmental Secrets of the Romualdo Formation, Araripe Basin | 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 Research Article Thin Section Microfossil Analysis: Unlocking Paleoenvironmental Secrets of the Romualdo Formation, Araripe Basin Maria Emilia Travassos Rios Tomé, David Holanda de Oliveira, Christiano Ng, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6430822/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 24 Feb, 2026 Read the published version in Facies → Version 1 posted 5 You are reading this latest preprint version Abstract This study aimed to investigate microfacies to infer paleoenvironmental interpretations of the Romualdo Formation during the Aptian/Albian of the Araripe Basin, Brazil. Samples were collected from three outcrops located in the eastern region and in the central south region of the Araripe Basin. The interpretations in this work were established by evaluating the stratigraphic sections and the subsequent preparation and analysis of 54 petrographic slides. Nine microfacies were recognized: Bioclastic Packstone/Grainstone with ostracods (BPGo); Peloidal bioclastic Grainstone/Packstone with intraclasts (BGPi); Impure Bioclastic Peloidal Packstone with foraminifera (BPfi); Impure Bioclastic Peloidal Packstone with organic matter (BPmoi); Laminated peloidal bioclastic Packstone (BLP); Feldspathic Immature Sandstone (FIS); Laminated boundstone (LB); Parallel-laminated Shale (So); Fine to Medium Sandstone with glauconite (FMSg). In addition, several groups of microfossils were identified on slides: ostracods (eg. Pattersoncypris , Damonella , Mongolianella , and Dicrorygma ), benctonic and planktonic foraminifera ( Spirosigmoilina , Quinqueloculina , Neoconorbina , Sigmoilinita tenuis , Microhedbergella ) and green algae ( Neomeris sp. and Brasiliporella sp.). These microfacies are related to the marine ingressions in the basin during the Aptian/Albian transition, indicating environments ranging from proximal to open marine, according to the microfauna and mineralogical elements described in the microfacies. Carbonate microfacies Paleoenvironment Petrography Aptian/Albian Full Text Cite Share Download PDF Status: Published Journal Publication published 24 Feb, 2026 Read the published version in Facies → Version 1 posted Editorial decision: Major Revision 03 Jun, 2025 Reviewers agreed at journal 13 May, 2025 Reviewers invited by journal 12 May, 2025 Editor assigned by journal 23 Apr, 2025 First submitted to journal 22 Apr, 2025 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. 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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-6430822","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":455579801,"identity":"ad0dccab-b807-4286-bac9-18960519c7b7","order_by":0,"name":"Maria Emilia Travassos Rios 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