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Published June 2011 | public
Journal Article

Formation of dolomite at 40–80 °C in the Latemar carbonate buildup, Dolomites, Italy, from clumped isotope thermometry

Abstract

The temperature of formation of replacement dolomite and δ^(18)O(H_(2)O) of dolomitizing fluid in the Latemar carbonate buildup, Dolomites, Italy, were estimated independently from carbonate clumped isotope thermometry. Dolomite formed at 42–72 ± 9–11 °C (±2 standard deviations, SD) from fluid with δ^(18)O(H_(2)O) that averages –0.3‰ ± 3.3‰ (Vienna standard mean ocean water; ±2 SD). The estimated temperature and δ^(18)O(H_(2)O) are similar to those of modern diffuse flow fluids at mid-ocean ridges, the kind of fluid that has been proposed previously as the dolomitizing fluid in the Latemar buildup, based on the trace element compositions of dolomite. Calcite in limestone preserves original δ^(18)O, but records clumped isotope temperatures, 44−76 ± 9−11 °C (±2 SD), that are higher than those at which the limestone formed. Temperature recorded by calcite, but not δ^(18)O, was likely reset during dolomitization. Clumped isotope thermometry has great potential for application to studies of burial and diagenesis by retrieving independent estimates of temperature and δ^(18)O(H_(2)O) with uncertainties as low as ±5 °C (±2 standard errors, SE) and ± 0.75‰ (±2 SE), respectively, from a single stable isotope analysis of a carbonate mineral.

Additional Information

© 2011 Geological Society of America. Received 22 October 2010; Revision received 4 February 2011; Accepted 9 February 2011. First published online May 4, 2011. Ferry thanks Weifu Guo, Kate Huntington, Aradhna Tripati, and Rose Came for training, assistance, and advice in the laboratory. We thank Magali Bonifacie for sharing her data on the laboratory calibration of the clumped isotope thermometer for dolomite. We acknowledge the helpful reviews by Kate Huntington and an anonymous reviewer. Research was supported by grants to Ferry from the National Science Foundation (EAR-0635608) and from donors of the Petroleum Research Fund administered by the American Chemical Society and to Eiler from the Dreyfus Foundation.

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023