POWRE: Experimental Study of Water-Rock Interactions on Mars

点击翻译按钮获取中文摘要

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.