ZHANG Hai-Wei1,2, CAI Yan-Jun1, AN Zhi-Sheng1, QIN Shi-Jiang1
1. Institue of Earth Environment, Chinese Academy of Sciences, State key Laboratory of Loss and Quaternary Geologe Xi'an 710075, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China
Abstract：Knowledge on the variations of oxygen and carbon isotope compositions in the transformation of speleothem primary aragonite to secondary calcite is the foundation of paleo-environmental studies using speleothem. A stalagmite SN15, which was collected from the Shennong Cave, Jiangxi Province, southeastern China, has been identified by XRD analyzing that its aragonite has partially inverted into calcite. The comparisons of carbon and oxygen isotopic data series between secondary calcite and corresponding primary aragonite within stalagmite SN15 indicate that the δ13C datum of calcite have a quite similar range to those of the aragonite, whereas the δ18O values of calcite are depleted about 0.2‰-1.4‰ at random. Our result suggests that the oxygen isotopic data of calcite can hardly be used to investigate the paleo-climatic changes with high-resolution. Carbon isotope composition of calcite seems to be inherited from the aragonite, but it should be cautious to use the carbon isotopic data in paleo-environmental studies because the mechanism of aragonite-to-calcite transformation has not been fully understood.
Key Words: stalagmite; aragonite; calcite recrystallize; carbon and oxygen isotopes
Bulletin of Mineralogy, Petrology and Geochemistry Vol. 33, No.1, 2014, page 31-37
