Role of Subsurface Brines in Salt Balance: The Case Study of the Caspian Sea and Kara Bogaz Bay
Role of Subsurface Brines in Salt Balance: The Case Study of the Caspian Sea and Kara Bogaz Bay
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DOI：
10.1007/s10498-008-9048-x
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发表时间：
2009-02
影响因子：
1.6
通讯作者：
N. Clauer;M. Pierret;S. Chaudhuri
中科院分区：
文献类型：
--
作者：
N. Clauer;M. Pierret;S. Chaudhuri
在最近的历史中，里海的水位波动很大，但对其原因没有达成共识。里海、卡拉博加兹和间隙水域沉积物的不同化学成分提供了进一步的了解。将间隙水的元素浓度和87sr /86Sr比值与里海和卡拉博加兹开阔水域的元素浓度和87sr /86Sr比值以及酸浸可提取组分进行了比较。间隙水的87sr /86Sr比值可以通过添加与附近泉水相似的地下水来解释。这些地下水的化学特征包括Cl/SO4、87Sr/86Sr、Ca/Sr和K/Rb比值分别为80、0.7086、250和1800。然而，它们的添加并不能解释里海和卡拉Bogaz水域的K/Rb比值的巨大差异，分别为7,630和17,550，这也意味着盐沉积是由向上迁移的地下水淋滤的。里海盆地南部沉积物间质水Na、Cl、so4含量低，沉积环境明显为缺氧环境。水中有关的化学变化也表明最近水文制度发生了变化，这可能是由流域形态的变化引起的。
The water level of the Caspian Sea fluctuated significantly during recent history, without consensus for the cause. The varied chemistry of the Caspian, Kara Bogaz and sediment a interstitial waters provides a further insight. Element concentrations and87Sr/86Sr ratios of the interstitial waters were compared to those of Caspian and Kara Bogaz open waters, and of acid-leached extractable components. The87Sr/86Sr ratios of the interstitial waters are explained by addition of subterranean waters similar to nearby spring waters. These subterranean waters yield chemical characteristics such as a Cl/SO4,87Sr/86Sr, Ca/Sr and K/Rb ratios of respectively 80, 0.7086, 250 and 1,800. However, their addition does not explain the large difference in the K/Rb ratio of the Caspian and Kara Bogaz waters, respectively at 7,630 and 17,550, which implies also a leaching of salt deposits by the upward migrating subterranean waters. The sediments of the southern Caspian basin, with low Na, Cl and SO4in their interstitial waters, deposited apparently in an anoxic environment. The related chemical changes in the waters are also indicative of a recent change in the hydrologic regime, possibly induced by a changing morphology of the drainage basin.