Incorporation of trace metals into microcodium as novel proxies for paleo-precipitation
Incorporation of trace metals into microcodium as novel proxies for paleo-precipitation
复制标题
将微量金属掺入微藻中作为古降水的新代理
DOI：
10.1016/j.epsl.2013.10.011
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发表时间：
2014-01
影响因子：
5.3
通讯作者：
Gaojun Li
中科院分区：
文献类型：
--
作者：
Tao Li;Gaojun Li
以中国黄土高原为例，首次将微量元素组成作为古代用指标。全新世古土壤中微量元素的Mg/Ca和Sr/Ca比值在近一个数量级的大范围内呈明显的正相关。在西北季风降水较少的地区，微镉的Mg/Ca和Sr/Ca比值较高。在相同的空间格局下，CLP上的水流Mg/Ca和Sr/Ca比值也出现了类似的大的正相关变化。微量元素的Mg/Ca和Sr/Ca比值在很大程度上受水流反映的土壤溶液组成的控制，而不是受分配系数的控制。由于次级方解石的不断沉淀，土壤溶液的组成也随着瑞利蒸馏而不断变化，这是造成微量元素和溪流中Mg/Ca和Sr/Ca比值大变化和正相关的原因。我们认为，当土壤水分被提取到一定程度时，中国黄土中的生物遗骸可能会变得不活跃，然后通过与高度演化的土壤溶质混合的淡水渗透而钙化成微钴。因此，微镉的Mg/Ca和Sr/Ca比值反映了高Mg/Ca和Sr/Ca比值的高度演化土壤溶质与低Mg/Ca和Sr/Ca比值的新鲜土壤水的混合比例，从而记录了古降水量。
Trace element compositions of microcodium are applied for the first time as possible paleo-proxies based on a case study on the Chinese Loess Plateau (CLP). The Mg/Ca and Sr/Ca ratios of the microcodium picked from the Holocene paleosol across the CLP show distinct positive correlation over large range of nearly one order of magnitude. Higher Mg/Ca and Sr/Ca ratios of microcodium are recorded in the sites on the northwestern CLP where less monsoonal rainfall is received. Similar large variation of the positively correlated Mg/Ca and Sr/Ca ratios has also been observed for the stream water on the CLP with the same spatial pattern. The Mg/Ca and Sr/Ca ratios of the microcodium seem to be largely controlled by the composition of soil solution as reflected by stream water rather than partition coefficient. Rayleigh distillation, and thus evolving composition of soil solution as a result of progressive precipitation of secondary calcite, is responsible for the large variation and positive correlation of the Mg/Ca and Sr/Ca ratios for both the microcodium and stream water. We propose that the bio-remains in Chinese loess may become inactive when the soil water is extracted to a degree, and then be calcified into microcodium by the infiltration of freshwater that is mixed with the highly evolved soil solutes. Thus, the Mg/Ca and Sr/Ca ratios of microcodium may record the paleo-precipitation amount by reflecting the mixing ratio between the highly evolved soil solutes with higher Mg/Ca and Sr/Ca ratios and the fresh soil water with lower Mg/Ca and Sr/Ca ratios.
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影响因子：
2.8
作者：
A. M. Alonso-Zarza;M. Sanz;J. Calvo;Pilar Estévez
通讯作者：
A. M. Alonso-Zarza;M. Sanz;J. Calvo;Pilar Estévez
影响因子：
5.8
作者：
Daniel C. Pope;S. Willett
通讯作者：
Daniel C. Pope;S. Willett
DOI：
--
发表时间：
1985
期刊：
--
影响因子：
--
作者：
Dongsheng Liu
通讯作者：
Dongsheng Liu
影响因子：
5.3
作者：
Shiling Yang;Z. Ding
通讯作者：
Shiling Yang;Z. Ding
δ13C 黄土总碳酸盐值：中国黄土高原干旱西北缘亚洲夏季风的敏感代理
影响因子：
3.9
作者：
Liu, Weiguo;Yang, Hong;Wang, Xulong
通讯作者：
Wang, Xulong