87Sr/86Sr and Sr/Ca in speleothems for paleoclimate reconstruction in Central China between 70 and 280 kyr ago

Hong Chun Li, Teh Lung Ku, Chen Feng You, Hai Cheng, R. Lawrence Edwards, Zhi Bang Ma, Wang Sheng Tsai, Mung Dar Li

研究成果: Article

35 引文 斯高帕斯(Scopus)

摘要

Limestone cave deposits (speleothems) provide archives for past changes in regional climates over a range of timescales. While δ18O and δ13C in speleothem calcite have been commonly used for reconstruction of paleoclimates, we report here further efforts in the use of 87Sr/86Sr and Sr/Ca signals in speleothem calcite to deduce paleomonsoon variability near the Loess Plateau of central China. A two end-member mass-balance model of concentration and isotopic composition of strontium in a cave system is used to estimate variation of the 87Sr/86Sr ratio in sediments overlying a limestone cave. We show that this ratio reflects climate-driven variations in the provenance and the extent of chemical weathering of the epikarstic sediments. The measurements of 87Sr/86Sr made on a well-dated stalagmite, SFL, from Buddha Cave (33°40N′ 109°05′E) show ratios of 0.71092 to 0.71133 (±0.00001 as 2σ) during relatively cold periods (e.g., Marine Isotope Stage (MIS) 5b, 5d, and 8), lower than ratios of 0.71133 to 0.71194 during relatively warm periods (e.g., MIS 5a, 5c, 5e, and 7). As changes in the Sr/Ca ratio may affect speleothem 87Sr/86Sr, we show that the direct use of speleothem 87Sr/86Sr is less ideal than our modeled 87Sr/86Sr for the exogenic Sr source above the cave as a paleomonsoon proxy. Using the δ18O, δ13C, Sr/Ca, and 87Sr/86Sr records of the stalagmite, we reconstruct the variability of the East Asian monsoon for the time period between 70 and 280 kyr ago. The results show that summer monsoons were more intense during interglacial periods than during glacial periods.

原文English
頁(從 - 到)3933-3947
頁數15
期刊Geochimica et Cosmochimica Acta
69
發行號16
DOIs
出版狀態Published - 2005 八月 15

All Science Journal Classification (ASJC) codes

  • Geochemistry and Petrology

指紋 深入研究「<sup>87</sup>Sr/<sup>86</sup>Sr and Sr/Ca in speleothems for paleoclimate reconstruction in Central China between 70 and 280 kyr ago」主題。共同形成了獨特的指紋。

  • 引用此