POWRE: Experimental Study of Water-Rock Interactions on Mars

9973345贝克静态和流过热液实验将在镁铁质和超镁铁质岩石成分上进行，这些岩石成分与已知存在于火星表面的岩石成分相似。 实验将在25-400摄氏度的温度下使用CO2饱和的水性流体或CO2 -蒸汽混合物进行。 所用的流体组合物的盐度范围为1000 ppm至几重量%的总溶解氯化物和硫酸盐，起始pH为2至8.5。 流体与岩石的比例在20：1到1：20之间. 温度和流体-岩石比预计将强烈控制蚀变的程度，而流体成分应影响所产生的矿物组合。 这些实验的结果将被用来确定已知的火星岩石样本（如ALH 84001）被火星地壳中的流体改变的条件。 这些信息将使人们深入了解已知火星岩石所暴露的水量，从而了解过去的水文条件和火星地壳中的水量平衡。 它还将表明原始生命形式可能存在于火星古代热液环境中的条件。 最后，实验数据应该有助于解释任何新的火星岩石样本，无论是陨石还是样本返回任务。

9973345BakerStatic and flow-through hydrothermal experiments will be performed on mafic and ultramafic rock compositions similar to those known to exist on the surface of Mars. Experiments will be performed at temperatures from 25-400 degrees C using CO2 -saturated aqueous fluids or CO2 -steam mixtures. The fluid compositions used will range in salinity from 1000 ppm to several wt % total dissolved chloride and sulfate, and in starting pH from 2 to 8.5. Fluid - rock ratios will range from 20:1 to 1:20. Temperature and fluid-rock ratio are expected to strongly control the extent of alteration, while fluid composition should affect the mineral assemblage produced. The results of these experiments will be used to determine the conditions under which known Martian rock samples such as ALH84001 were altered by fluids in the Martian crust. This information will provide insight into the amount of water to which known Martian rocks have been exposed and thereby into past hydrologic conditions and the water budget in the Martian crust. It will also indicate the conditions under which primitive life forms might have existed in ancient hydrothermal environments on Mars. Finally, the experimental data should aid in the interpretation of any new Martian rock samples acquired either as meteorites or by sample-return missions.