Academic Journal
Thermally-induced clumped isotope resetting in belemnite and optical calcites: Towards material-specific kinetics
| العنوان: | Thermally-induced clumped isotope resetting in belemnite and optical calcites: Towards material-specific kinetics |
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| المؤلفون: | Looser, Nathan, Petschnig, Paul, Hemingway, Jordon, id_orcid:0 000-0002-8299-2255, Fernandez, Alvaro, Grafulha Morales, Luiz, Perez-Huerta, Alberto, Vickers, Madeleine L., Price, Gregory D., Schmidt, Max W., Bernasconi, Stefano M., id_orcid:0 000-0001-7672-8856 |
| المصدر: | Geochimica et Cosmochimica Acta, 350 |
| بيانات النشر: | Elsevier |
| سنة النشر: | 2023 |
| المجموعة: | ETH Zürich Research Collection |
| مصطلحات موضوعية: | Carbonate clumped isotopes, Solid-state bond reordering, Mineral–water isotopic exchange, Belemnite rostral calcite, Optical calcite |
| الوصف: | The application of carbonate clumped isotope (Δ47) thermometry in deep-time is often limited by modification of the original temperature signal by thermal resetting. New modeling approaches to estimate the initial isotopic composition of partially reset calcites and maximal burial temperatures, however, open promising avenues in temperature reconstruction. Such approaches strongly depend on laboratory-derived kinetic parameters of calcite materials, which may differ in their microstructure, water content and distribution, and minor and trace element composition, and thus may have different resetting kinetics. The rostra of belemnites, an extinct group of mollusks with a wide temporal and spatial occurrence in the Mesozoic, have been extensively used for deep-time paleoclimate reconstructions using oxygen isotope geochemistry. Belemnites are also important targets for clumped isotope-based temperature reconstructions, but often are found to have reset Δ47 compositions. Here, we present results from heating experiments on belemnite rostral calcite and optical calcite and provide belemnite-specific kinetic parameters for clumped isotope resetting. We show that belemnite calcite is altered faster and at lower temperatures than optical calcite and all other calcites reported in previous studies. We suggest that fast initial resetting results from oxygen isotope exchange of belemnite calcite with internal skeletal water present as fluid inclusions or organic-derived water, a process completed within 2–4 min at the experimental temperatures used here. Extrapolation to geological timescales using different solid-state bond reordering models shows that belemnite calcite resetting starts at lower burial temperatures than brachiopod, spar, and optical calcites. This susceptibility to thermal resetting results in a measurable (+3 °C) increase of the apparent Δ47 temperature even under shallow to moderate burial conditions (i.e., 40–50 °C for 106–107 years timescales). Following the overprint to higher apparent Δ47 ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/application/pdf |
| اللغة: | English |
| Relation: | info:eu-repo/semantics/altIdentifier/wos/000990636500001; info:eu-repo/grantAgreement/SNF/Projekte MINT/169849; http://hdl.handle.net/20.500.11850/608967 |
| DOI: | 10.3929/ethz-b-000608967 |
| الاتاحة: | https://hdl.handle.net/20.500.11850/608967 https://doi.org/10.3929/ethz-b-000608967 |
| Rights: | info:eu-repo/semantics/openAccess ; http://creativecommons.org/licenses/by/4.0/ ; Creative Commons Attribution 4.0 International |
| رقم الانضمام: | edsbas.4F291528 |
| قاعدة البيانات: | BASE |
| DOI: | 10.3929/ethz-b-000608967 |
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