Deciphering the diagenetic history of the El Abra Formation of eastern Mexico using reordered clumped isotope temperatures and U-Pb dating Michael Lawson1,†, Brock J. Shenton1 , Daniel A. Stolper2 , John M. Eiler3 , E. Troy Rasbury4 , Thomas P. Becker1 , Charity M. Phillips-Lander1,§, Antonio S. Buono1 , Stephen P. Becker1 , Robert Pottorf1 , Gary G. Gray1 , Don Yurewicz1 , and Jonas Gournay1 1 ExxonMobil Upstream Research Company, Spring, Texas 77389, USA 2 Department of Earth and Planetary Science, University of California, Berkeley, California, 94720, USA 3 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA 4 Department of Earth Sciences, Stony Brook University, Stony Brook, New York 11794, USA †
[email protected] § Present address: Department of Geoscience, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA Abstract Carbonates form ubiquitously throughout the history of deposition, burial, and uplift of basins. As such, they potentially record the environmental conditions at the time of formation. Carbonate clumped isotopes provide the temperature of precipitation but can be internally reordered if the host rock is exposed to elevated temperatures over geologic time scales. Here, we exploited this kinetic behavior by analyzing multiple generations of cements that capture the range of environments experienced by the El Abra Formation from eastern Mexico. From this, we developed a quantitative diagenetic history for these different phases of cementation. We observed a 70 °C range in clumped isotope temperatures from 64 °C to 134 °C for these cements, which is not compatible with their inferred precipitation environments. This suggests that bond reordering occurred during burial but did not fully reorder all cements to a common apparent temperature.