From magmatic flow to hydrothermal collapse: AMS constraints on structural and alteration dynamics in the Shadan Au-rich porphyry deposit, South Khorasan, Eastern Iran

From magmatic flow to hydrothermal collapse: AMS constraints on structural and alteration dynamics in the Shadan Au-rich porphyry deposit, South Khorasan, Eastern Iran | 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 From magmatic flow to hydrothermal collapse: AMS constraints on structural and alteration dynamics in the Shadan Au-rich porphyry deposit, South Khorasan, Eastern Iran Sung-Hyo Yun, Maryam Sheibi, Davood Raeisi, Mohammad Lotfi, Cheolwoo Chang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8728700/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Magmatic processes and subsequent hydrothermal alterations within porphyry deposits are well-documented through the analysis of mineral chemistry and the magnetic fabrics of their host intrusions. This study integrates structurs, petrography, mineral chemistry, and anisotropy of magnetic susceptibility (AMS) data to investigate the evolution of magmatic and hydrothermal fabrics in the Shadan porphyry gold deposit, located in northeastern Iran. Fresh monzonitic to monzodioritic intrusions exhibit primary magmatic fabrics characterized by oblate AMS ellipsoids, predominantly aligned with magnetite. Progressive hydrothermal alteration—including sodic–calcic, potassic, phyllic, propylitic, and argillic zones—systematically modifies these fabrics, resulting in prolate ellipsoids and a reduction in bulk magnetic susceptibility. These alterations are associated with the destruction of magnetite, hematitization, the replacement of biotite by sericite, and Fe–Mg re-equilibration in amphibole, biotite, and chlorite. Quartz–carbonate and late argillic zones exhibit very weak magnetic susceptibility due to the oxidation and obliteration of primary magnetic minerals. The findings indicate that AMS effectively records the superimposed magmatic and hydrothermal processes, providing quantitative insights into the physicochemical evolution, alteration zoning, and mineralogical transformations in porphyry gold systems. This methodological approach underscores the significance of magnetic fabrics in guiding predictive exploration Earth and environmental sciences/Solid Earth sciences/Mineralogy Earth and environmental sciences/Solid Earth sciences/Geodynamics Mineral chemistry Magnetic fabric Hydrothermal alteration Au-rich porphyry deposit Iran Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementrayI.xlsx Supplementary I SupplementaryII.xlsx Supplementary II SupplementaryIII.xlsx Supplementary III Cite Share Download PDF Status: Posted Version 1 posted 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-8728700","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":593734960,"identity":"bd53546d-7252-448d-af14-f6ce85dc7d47","order_by":0,"name":"Sung-Hyo 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