Shallow burial alteration of dolomite and limestone clumped isotope geochemistry

Research Article| June 01, 2016 Shallow burial alteration of dolomite and limestone clumped isotope geochemistry Ian Z. Winkelstern; Ian Z. Winkelstern Department of Earth and Environmental Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, Michigan 48109, USA Search for other works by this author on: GSW Google Scholar Kyger C Lohmann Kyger C Lohmann Department of Earth and Environmental Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, Michigan 48109, USA Search for other works by this author on: GSW Google Scholar Geology (2016) 44 (6): 467–470. https://doi.org/10.1130/G37809.1 Article history received: 18 Feb 2016 rev-recd: 20 Apr 2016 accepted: 22 Apr 2016 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Ian Z. Winkelstern, Kyger C Lohmann; Shallow burial alteration of dolomite and limestone clumped isotope geochemistry. Geology 2016;; 44 (6): 467–470. doi: https://doi.org/10.1130/G37809.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Carbonate clumped isotope paleothermometry is a promising method for paleoclimate reconstructions and understanding diagenetic processes, although clumped isotope compositions (measured as Δ47 values) can be altered by recrystallization and thermal resetting. Several studies have investigated the effects of deep burial and exhumation on Δ47 values; we present Δ47 values of samples from an ∼4500-m-long drill core from Andros Island, Bahamas, which represent the spectrum from shallow to deep burial conditions. These limestones and dolomites originally formed under near-surface temperature conditions, which are reflected by ∼27 °C Δ47 temperatures in samples buried to <∼1.3 km depth. Below this depth, calculated Δ47 temperatures increase by ∼10 °C, indicating a shift from preserved near-surface temperatures to diagenetically modified values. Importantly, this shift is not accompanied by a change in δ18O and δ13C values or cathodoluminescence, and non-uniform micrometer-scale crystallization is observed in both Δ47-altered and unaltered rocks. Similar Δ47 temperatures recorded by each carbonate phase suggest that mineral-specific differences are minor. Fine-grained dolomites and calcites are viable materials for recording surface temperature conditions, and both are susceptible to alteration of their primary clumped isotope abundances during burial diagenesis. Our results demonstrate that original Δ47 values of fine-grained carbonates can be altered under mild diagenetic conditions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.