The CheMin instrument on the Mars Science Laboratory rover Curiosity detected ubiquitous high abundances (∼15–70 wt%) of X‐ray amorphous components (AmCs) in ancient sedimentary rocks of Gale crater. Mechanisms and timing of formation for the AmCs are poorly constrained, and could include volcanic, impact, or aqueous processes. We explore trends in AmC composition and abundance, and look for systematic compositional variation between sites within Gale crater. AmC compositions were estimated indirectly based on bulk chemistry and the nature and abundance of the crystalline phases for 19 sedimentary rock samples. AmC abundances positively correlate with AmC SiO₂ contents, and a mixing relationship appears to exist between SiO₂‐rich and FeO_T‐rich AmC endmembers. Endmember compositions are inconsistent with volcanic or impact glass alone, and so we conclude that the SiO₂ and FeO_T contents formed largely through aqueous processes. Cross‐cutting relationships and geologic context provide evidence that the most SiO₂‐rich AmCs observed in Gale crater thus far may result from interactions with localized fluids during late diagenesis. AmCs with moderate to low SiO₂ contents likely formed earlier (before or soon after sediment deposition). Thus, the AmC SiO₂ and FeO_T contents in Gale crater rocks represent mixtures of sedimentary materials formed over most of the sedimentary history of Gale crater, starting before the first sediments were deposited in the crater (late Noachian), and ending well after the youngest sediments were lithified (at least mid‐Hesperian). However, it remains unclear how these metastable minerals have persisted through billions of years of diagenesis in Gale crater sediments.

中文翻译：

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火星大风火山口沉积岩中的X射线无定形成分：古代形成和长期水活动的证据

火星科学实验室流动站上的CheMin仪器好奇号探测到了大风火山口古代沉积岩中普遍存在的X射线无定形成分（AmCs）的高丰度（〜15–70 wt％）。AmCs的形成机理和形成时间受限制较弱，可能包括火山作用，撞击过程或水成过程。我们探索AmC组成和丰度的趋势，并在大风火山口内的站点之间寻找系统的组成变化。根据大体化学以及19个沉积岩样品的结晶相的性质和丰度，间接估算了AmC的组成。AmC的丰度与AmC的SiO ₂含量呈正相关，并且富SiO ₂和FeO _T之间似乎存在混合关系丰富的AmC最终成员。末端构件的组成与单独的火山玻璃或冲击玻璃不一致，因此我们得出的结论是，SiO ₂和FeO _T的含量主要是通过水性过程形成的。横切关系和地质背景提供了证据，表明到目前为止，在大风火山口中观察到的大多数SiO ₂富集的AmC可能是由于在成岩后期与局部流体的相互作用所致。具有中等至低SiO ₂含量的AmC可能较早形成（沉积物沉积之前或之后不久）。因此，AmC SiO ₂和FeO _T大风火山口岩石中的含量表示大风火山口大部分沉积历史中形成的沉积物混合物，始于第一个沉积物沉积在火山口中（Noachian晚期），直到最年轻的沉积物岩化（至少在中期）之后才结束。西班牙语）。然而，尚不清楚这些亚稳矿物如何在大风火山口沉积物中经历数十亿年的成岩作用后持续存在。