Field Investigations of Chemical Partitioning and Aqueous Chemistry of Freezing Closed‐Basin Lakes in Mongolia as Analogs of Subsurface Brines on Icy Bodies
Field Investigations of Chemical Partitioning and Aqueous Chemistry of Freezing Closed‐Basin Lakes in Mongolia as Analogs of Subsurface Brines on Icy Bodies
复制标题
蒙古冻结闭盆湖泊的化学分配和水化学的实地调查，作为冰体上地下盐水的模拟
DOI：
10.1029/2021je006972
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Takahashi Yoshio
中科院分区：
文献类型：
--
作者：
Yoda Masahiro;Sekine Yasuhito;Fukushi Keisuke;Kitajima Takuma;Gankhurel Baasansuren;Davaasuren Davaadorj;Gerelmaa Tuvshin;Ganbat Shuukhaaz;Shoji Daigo;Zolotov Mikhail Y.;Takahashi Yoshio
几个冰体（例如，木卫二和谷神星）可能拥有近地表的盐水储层，这被认为是其表面盐的来源。以前的研究提出了一个过程，即覆盖冰层捕获盐从冻结，地下水库。然而，很少有现场调查已经进行了调查的化学分配和水化学冻结盐水储层在陆地类似物。在这里，我们报告的冬季实地调查结果，以冰覆盖，封闭盆地盐湖在戈壁湖谷，蒙古。我们发现，表面冰表现出复杂的功能，包括压力脊形成的压缩力和湿裂纹形成的张力。后者为冰层和表面提供盐度。除了湿裂缝，盐湖底层水，沿着悬浮物，在向下冻结过程中不断被捕获在冰层的孔隙中。使用组合的质量平衡和低温水化学模型，我们再现了由于Na+，Cl−和SO42−的截留而导致的冰盐度，这表明可以根据我们现有的知识来理解这些物种在冰体上的冷冻盐水储层中的化学分配。在湖底水中，碳酸盐的亚稳相（即，无定形碳酸镁和单水方解石）在控制可沉淀的Mg 2+和Ca 2+浓度以及碱度方面发挥着关键作用，凸显了碳酸盐亚稳相在冰体地下盐水储层水化学中的重要性。亚稳相可能是卤水储层中新喷发物质的指示物。
Several icy bodies (e.g., Europa and Ceres) likely possess near‐surface brine reservoirs, which are considered to be sources of salts on their surfaces. Previous studies have proposed processes whereby an overlying ice layer captures salinity from a freezing, subsurface reservoir. However, few field investigations have been conducted to investigate chemical partitioning and aqueous chemistry in freezing brine reservoirs in terrestrial analogs. Here we report results of winter field surveys to ice‐covered, closed‐basin saline lakes in the Valley of the Gobi Lakes, Mongolia. We found that the surface ice exhibited complex features, including both pressure ridges formed by compressive forces and wet cracks formed by tensile forces. The latter provides salinity to the ice layer and surface. In addition to wet cracks, saline lake bottom‐water, along with suspended matter, was continuously captured within the pores of the ice layer during downward freezing. Using a combined mass balance and low‐temperature aqueous chemistry model, we reproduced the ice salinity due to entrapment of Na+, Cl−, and SO42−, suggesting that chemical partitioning of these species in freezing brine reservoirs on icy bodies can be understood based on our current knowledge. In the lake bottom‐water, the metastable phase of carbonates (i.e., amorphous Mg‐carbonate and monohydrocalcite) play key roles in controlling the concentrations of precipitable Mg2+and Ca2+and alkalinity, highlighting the importance of metastable phase of carbonate in the aqueous chemistry of subsurface brine reservoirs on icy bodies. Metastable phases might be indicators of freshly erupted materials from brine reservoirs.
登录
查看更多内容
DOI：
--
发表时间：
1979
期刊：
影响因子：
--
作者：
J. Dionne
通讯作者：
J. Dionne
影响因子：
14.1
作者：
De Sanctis, M. C.;Ammannito, E.;Russell, C. T.
通讯作者：
Russell, C. T.
木卫二表面物质的化学性质及其与地下海洋的关系
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
T. Orlando;T. McCord;G. Grieves
通讯作者：
G. Grieves
欧罗巴上由碟形基台形成的透镜状结构
影响因子：
3.2
作者：
M. Manga;C. Michaut
通讯作者：
C. Michaut
木星卫星欧罗巴异质盐壳的热状态和复杂地质
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
O. Prieto;J. Kargel
通讯作者：
J. Kargel