Khan Sabrina Y, Stack Kathryn M, Yingst R Aileen, Bergmann Kristin
Jet Propulsion Laboratory California Institute of Technology CA Pasadena USA.
Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology MA Cambridge USA.
J Geophys Res Planets. 2022 Nov;127(11):e2021JE007095. doi: 10.1029/2021JE007095. Epub 2022 Nov 17.
The morphology and composition of clasts have the potential to reveal the nature and extent of erosional processes acting in a region. Dense accumulations of granule- to pebble-sized clasts covering the ground throughout the Glen Torridon region of Gale crater on Mars were studied using data acquired by the Mars Science Laboratory Curiosity rover between sols 2300 and 2593. In this study, measurements of shape, size, texture, and elemental abundance of unconsolidated granules and pebbles within northern Glen Torridon were compiled. Nine primary clast types were identified through stepwise hierarchical clustering, all of which are sedimentary and can be compositionally linked to local bedrock, suggesting relatively short transport distances. Several clast types display features associated with fragmentation along bedding planes and existing cracks in bedrock. These results indicate that Glen Torridon clasts are primarily the product of in-situ physical weathering of local bedrock.
碎屑的形态和成分有可能揭示一个地区侵蚀过程的性质和程度。利用火星科学实验室“好奇号”火星车在第2300个火星日至2593个火星日期间获取的数据,对火星盖尔陨石坑格伦托里登地区地面上覆盖的颗粒至卵石大小的碎屑密集堆积物进行了研究。在这项研究中,汇编了格伦托里登北部未固结颗粒和卵石的形状、大小、纹理和元素丰度的测量数据。通过逐步层次聚类识别出九种主要碎屑类型,所有这些碎屑都是沉积性的,并且在成分上可以与当地基岩联系起来,这表明搬运距离相对较短。几种碎屑类型显示出与沿层面和基岩中现有裂缝破碎相关的特征。这些结果表明,格伦托里登碎屑主要是当地基岩原地物理风化的产物。