Li/Ca ratios of ostracod shells at Lake Qinghai, NE Tibetan Plateau, China: a potential temperature indicator
Li/Ca ratios of ostracod shells at Lake Qinghai, NE Tibetan Plateau, China: a potential temperature indicator
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DOI：
10.1007/s12665-012-1617-z
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发表时间：
2012-03
影响因子：
2.8
通讯作者：
Zhengjie Zhu;Jing-an Chen;Da-hua Li;Shicong Ren;Fang Liu
中科院分区：
文献类型：
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作者：
Zhengjie Zhu;Jing-an Chen;Da-hua Li;Shicong Ren;Fang Liu
获取近2000年来连续、高分辨率的自然记录是古气候研究的热点问题。近年来的研究表明，碳酸盐岩的Li/Ca和Mg/Li比值是海洋过去环境变化的潜在示踪剂，但很少用于湖泊的古气候重建。单种可有效避免种间效应。结合已有的沉积速率，成功地重建了青海湖近800年来介形类壳Li/Ca比值的210pb和137cs数据。通过比较都兰和祁连山地区气象记录和树木年轮宽度反演的Li/Ca比值与温度的关系，发现介形虫壳的Li/Ca比值与温度呈负相关。温度越高，对应的Li/Ca比值越低，反之亦然，说明介形虫壳的Li/Ca比值是温度变化的有效指标。因此，利用更多湖泊碳酸盐的Li/Ca比值进行深入研究，进一步揭示其古温度意义是值得的。
Acquiring continuous and high-resolution natural records in recent 2,000 years is the hot issue in the palaeoclimate research. Recent studies revealed that Li/Ca and Mg/Li ratio of carbonate is a potential tracer of past environmental changes in the oceans, and is seldom applied for palaeoclimate reconstruction in lakes. To make full understanding of the potential of Li/Ca ratios of carbonates in lakes, Li/Ca ratios of monospecific ostracod shellEucypris inflatewith similar size in the lacustrine sediment core from Lake Qinghai, NE Tibetan Plateau have been analysed for the first time. Single species can effectively avoid the interspecies effects. In combination with the sedimentation rate that existed, data derived from210Pb and137Cs, downcore variations of Li/Ca ratios of ostracod shells during the past 800 years in Lake Qinghai have been reconstructed successfully. By comparing Li/Ca ratios and temperature inferred from meteorological records and tree ring widths in Dulan and Qilianshan in adjacent regions, Li/Ca ratios of ostracod shells negatively correlate with temperature. Higher temperature corresponds with lower Li/Ca ratios, and vice versa, indicating that Li/Ca ratio of ostracod shells is an effective indicator for temperature variations. Therefore, ongoing in-depth investigation using Li/Ca ratios of carbonates in more lakes to further reveal its palaeotemperature implications would be deserved.