Characterization of aqueous alteration and formation of salty exposures at Ius Chasma, Mars (NOTE: First author Wilk was a SETI Institute REU 2020 student)
Characterization of aqueous alteration and formation of salty exposures at Ius Chasma, Mars (NOTE: First author Wilk was a SETI Institute REU 2020 student)
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火星 Ius Chasma 水蚀变和盐暴露形成的特征（注：第一作者 Wilk 是 SETI 研究所 REU 2020 学生）
DOI：
10.1016/j.icarus.2023.115800
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发表时间：
2024
期刊：
影响因子：
3.2
通讯作者：
Seelos, Frank
中科院分区：
文献类型：
--
作者：
Wilk, Kierra A.;Bishop, Janice L.;Weitz, Catherine M.;Parente, Mario;Saranathan, Arun M.;Itoh, Yuki;Gross, Christoph;Flahaut, Jessica;Seelos, Frank
Ius Chasma 中有趣的露头为了解火星水手谷过去的水流过程提供了一个窗口。该地区富含水合硫酸盐矿物，但 Ius Chasma 的一个区域包含页硅酸盐、蛋白石和具有不寻常光谱特征的其他材料。 Geryon Montes 是一座东西走向的地垒，将 Ius 峡谷划分为北部和南部峡谷。这项研究利用图像校准和特征提取技术的最新进展来分析由紧凑型火星侦察成像光谱仪 (CRISM) 获取的高光谱图像。具体来说，在 Ius Chasma 含层状硅酸盐和含硫酸盐区域的边界处分离出吸收在 2.21–2.23 和 2.26–2.28 μm 处的独特光谱“双峰”特征，并对其进行了调查，以表征可能代表火星气候变化的露头。我们记录并绘制了这种与层状硅酸盐和蛋白石相关的“双峰”材料的三种不同形式。对覆盖在高分辨率立体相机 (HRSC) 和高分辨率成像科学实验 (HiRISE) 图像上的 CRISM 生成的成分图的分析表明，这些水合露头沿着 Geryon Montes 缺口下方的围岩存在，毗邻含有丰富水合硫酸盐的峡谷。我们的调查支持这些独特的蚀变阶段是通过围岩中古代蒙脱石的酸蚀形成的，因为硫酸盐盐水在 Geryon Montes 的裂口处溢出了 Ius Chasma 的南部峡谷，并渗透到了更深的北部峡谷。
Intriguing outcrops in Ius Chasma provide a window into past aqueous processes in Valles Marineris, Mars. Hydrous sulfate minerals are abundant throughout this region, but one area in Ius Chasma includes phyllosilicates, opal, and additional materials with unusual spectral features. This study at Geryon Montes, an east-west horst that divides Ius Chasma into a northern and southern canyon, exploits recent advances in image calibration and feature extraction techniques for analysis of hyperspectral images acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Specifically, a unique spectral “doublet” feature with absorptions at 2.21–2.23 and 2.26–2.28 μm is isolated at the border of phyllosilicate-bearing and sulfate-bearing regions in Ius Chasma and surveyed to characterize outcrops that may represent a changing climate on Mars. We document and map three distinct forms of this “doublet” material in relation to phyllosilicates and opal. Analyses of compositional maps derived from CRISM overlain on High Resolution Stereo Camera (HRSC) and High Resolution Imaging Science Experiment (HiRISE) imagery has revealed the presence of these hydrated outcrops along the wall rocks below a breach in the Geryon Montes, bordering a canyon containing abundant hydrated sulfates. Our investigation supports formation of these unique alteration phases through acid alteration of ancient smectites in the wall rock as the sulfate brine overflowed the south canyon of Ius Chasma at the breach in Geryon Montes and penetrated the deeper northern canyon.