摘要
The 87Sr/86Sr ratios of silicate (acid-insoluble, AI) and carbonate (acid-soluble, AS) of the lake sediments from the Daihai Lake, Inner Mongolia, since the last 500 years are measured respectively, indicating that chemical weathering of silicate minerals was in an early stage since the Little Ice Age within the Daihai watershed by combination with mineral constitute, Rb/Sr ratio and CaCO3 content in the sediments. During the Little Ice Age maximum, an evi-dent peak in the 87Sr/86Sr ratios of both silicate and carbon-ate in sediments suggests that a cold climate condition is un-favorable to dissolving radiogenic strontium from silicate minerals. Meanwhile, the variation of 87Sr/86Sr ratios of sili-cate and carbonate also reflects a projected warming climate favorable to intensifying chemical weathering after the Little Ice Age. Consequently, the 87Sr/86Sr ratio of both silicate and carbonate in inland lake sediments can be used as an effec-tive proxy of the past climate in single watershed.
The 87Sr/86Sr ratios of silicate (acid-insoluble, AI) and carbonate (acid-soluble, AS) of the lake sediments from the Daihai Lake, Inner Mongolia, since the last 500 years are measured respectively, indicating that chemical weathering of silicate minerals was in an early stage since the Little Ice Age within the Daihai watershed by combination with mineral constitute, Rb/Sr ratio and CaCO3 content in the sediments. During the Little Ice Age maximum, an evi-dent peak in the 87Sr/86Sr ratios of both silicate and carbon-ate in sediments suggests that a cold climate condition is un-favorable to dissolving radiogenic strontium from silicate minerals. Meanwhile, the variation of 87Sr/86Sr ratios of sili-cate and carbonate also reflects a projected warming climate favorable to intensifying chemical weathering after the Little Ice Age. Consequently, the 87Sr/86Sr ratio of both silicate and carbonate in inland lake sediments can be used as an effec-tive proxy of the past climate in single watershed.
基金
This work was supported by the National Natural Science Foundation of China (Grant No. 40003001)
the National Key Basic Research Devel-opment Program (Grant No. G1999043400) and Nanjing Institute of Geography and Limnology Director Foundation (Grant No
