Laboratory simulations of Mars aqueous geochemistry
Laboratory simulations of Mars aqueous geochemistry
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DOI：
10.1016/j.icarus.2004.03.016
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发表时间：
2004-08-01
期刊：
影响因子：
3.2
通讯作者：
Mellon, MT
中科院分区：
文献类型：
--
作者：
Bullock, MA;Moore, JM;Mellon, MT
我们报告了一项实验室实验，在该实验中，我们允许snc衍生的矿物混合物在模拟火星大气下与纯水反应7个月。这些实验是在一个大气压和三种不同的温度下进行的，目的是模拟火星上最有可能存在液态水和岩石相互作用的地下条件。溶解在我们生产的溶液中的主要阳离子是Ca2+， Mg2+， Al3+和Na+，而主要阴离子是溶解的C， F-， SO42-和Cl-。典型溶液pH为4.2 ~ 6.0。我们合成的硫酸盐-氯化物盐水中的元素丰度模式与陆地海水或大陆水域的元素丰度模式明显不同，然而，它们与火星探路者号和海盗1号和2号着陆点在火星沉积物中测量到的元素丰度模式非常相似。这表明，随着时间的推移，火星风化层中的盐可能是表面或地下液态水与玄武岩相互作用的结果，当时火星的大气成分与今天的大气成分相似。如果大部分可移动的表面层是在诺亚亚时期形成的，当时侵蚀率比现在高得多，如果这一层的盐成分是均匀的，那么火星沉积物中的盐总量与地球海洋中的盐总量大致相同。沉积这么多盐所需的最小循环水量大约相当于全球625英尺深的水层。(C) 2004爱思唯尔公司版权所有。
We report on laboratory experiments in which we allowed an SNC-derived mineral mix to react with pure water under a simulated Mars atmosphere for 7 months. These experiments were performed at one bar and at three different temperatures in order to simulate the subsurface conditions that most likely exist where liquid water and rock interact on Mars today. The dominant cations dissolved in the solutions we produced, which may be characterized as dilute brines, are Ca2+, Mg2+, Al3+, and Na+, while the major anions are dissolved C, F-, SO42- and Cl-. Typical solution pH was in the range of 4.2-6.0. Abundance patterns of elements in our synthetic sulfate-chloride brines are distinctly unlike those of terrestrial ocean water or continental waters, however, they are quite similar to those measured in the martian fines at the Mars Pathfinder and Viking 1 and 2 Landing sites. This suggests that salts present in the martian regolith may have formed over time as a result of the interaction of surface or subsurface liquid water with basalts in the presence of a martian atmosphere similar in composition to that of today. If most of the mobile surface layer was formed during the Noachian when erosion rates were much higher than at present, and if this layer is homogeneous in salt composition, the total amount of salt in the martian fines is approximately the same as in the Earth's oceans. The minimum quantity of circulating water necessary to deposit this amount of salt is approximately equivalent to a global layer 625 in deep. (C) 2004 Elsevier Inc. All rights reserved.