Extensive hydrated silica materials in western Hellas Basin, Mars
Extensive hydrated silica materials in western Hellas Basin, Mars
复制标题
火星希腊盆地西部存在丰富的水合二氧化硅材料
DOI：
10.1016/j.icarus.2013.08.005
复制
发表时间：
2013
期刊：
影响因子：
3.2
通讯作者：
N. Thomas
中科院分区：
文献类型：
--
作者：
J. Bandfield;E. Amador;N. Thomas
近红外光谱数据表明，存在水合的、结晶较差的二氧化硅，而此前在希腊盆地发现了高体积二氧化硅含量。在这些区域没有发现其他水相，沉积物可能几乎是纯的。含硅表面沿着西部盆地边缘650公里的有限海拔范围内零星暴露，并显示出各种表面纹理，表明材料已被重新加工，但没有被远距离运输。高丰度和缺乏伴生水相表明，该地区在诺瓦契期存在高水岩比，但没有升温，也没有石英成岩所需的时间。含硅物质可能是通过饱和二氧化硅地下水来源的直接沉淀形成的，尽管其他形成机制也是合理的。
Near-infrared spectral data indicate the presence of hydrated, poorly crystalline silica where high bulk silica contents have been previously identified in Hellas Basin. No other aqueous phases are identified in these regions and the deposits may be nearly pure. The silica-bearing surfaces are sporadically exposed along a 650 km stretch of the western basin rim within a limited elevation range and display a variety of surface textures suggesting that the materials have been reworked, but not transported large distances. The high abundances and lack of associated aqueous phases indicate that high water to rock ratios were present in the region during the Noachian period but without elevated temperatures or for durations necessary for quartz diagenesis. The silica-bearing materials may have formed via direct precipitation from silica saturated groundwater sources, although other formation mechanisms are also plausible.