Physicochemical properties of concentrated Martian surface waters
Physicochemical properties of concentrated Martian surface waters
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火星表面浓缩水的物理化学特性
DOI：
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发表时间：
2011
期刊：
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通讯作者：
J. Grotzinger
中科院分区：
文献类型：
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作者：
N. Tosca;S. McLennan;M. Lamb;J. Grotzinger
了解控制化学沉积的过程是从地球和火星上保存的岩石记录中破译古气候条件的重要一步。子午线平原水下沉积的明确证据，水手谷地区广泛的盐矿物沉积，以及盐沃茨在形成最近的地貌特征中可能发挥的作用，都强调了需要了解火星上高浓度溶液的物理性质，以及它们独特的化学性质。使用热力学模型预测盐矿物溶解度，我们产生可能的盐水组合物，从碳酸氢盐为主的硫酸盐为主，并预测其盐矿物学。对于每个盐水组合物，然后，我们估计了一些热，运输和依数性使用已开发的高浓度多组分电解质溶液的模型。现有的实验数据和理论模型，使这些物理化学性质的估计包括，在大多数情况下，预期的化学变化可能火星盐水。这些估计允许在建立一个详细的分析物理沉积在古代火星表面的重大进展，并允许更准确的预测热行为和物质的扩散运输通过化学不同的解决方案在相对非标准的条件下。
Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions.