A Diverse Array of Fluvial Depositional Systems in Arabia Terra: Evidence for mid-Noachian to Early Hesperian Rivers on Mars
A Diverse Array of Fluvial Depositional Systems in Arabia Terra: Evidence for mid-Noachian to Early Hesperian Rivers on Mars
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DOI：
10.1029/2019je005976
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发表时间：
2019-07-01
影响因子：
4.8
通讯作者：
Williams, Rebecca M. E.
中科院分区：
文献类型：
--
作者：
Davis, Joel M.;Gupta, Sanjeev;Williams, Rebecca M. E.
分支成蜿蜒的山脊系统，长数百公里，由分层地层组成，在火星阿拉伯地的大部分地区都有。这些山脊被解释为沉积河道，现在以倒置地形的形式保存下来。在这里，我们使用高分辨率图像和地形数据集来研究这些沉积系统的形态，并展示它们与相关河流地貌关系的关键例子。倒置河道系统可能由硬化砾岩、砂岩和泥岩体组成，形成多层河道地层。河道系统与局部盆地和硬化的沉积丘相交，我们将其解释为古湖泊沉积。一些倒转河道位于侵蚀河谷网络中，这些网络具有区域性和局部集水区。倒转河道通常出现在河谷网的下坡段，有时也出现在盆地边缘，并观察到许多不同的过渡形态。这些关系表明了一个复杂的侵蚀和沉积历史，可能受到水或沉积物通量变化或基准面变化的控制。其他倒转水道系统没有明确保存的集水区，可能由于高地地区的区域重铺而丢失。沉积物可能通过阿拉伯地向二分界输送，并储存在局部和区域尺度的盆地中。区域地层关系表明，这些体系活跃于中挪亚世至早期希世。这些系统的形态支持早期火星气候，其特征是长时间的降水和径流。
Branching to sinuous ridges systems, hundreds of kilometers in length and comprising layered strata, are present across much of Arabia Terra, Mars. These ridges are interpreted as depositional fluvial channels, now preserved as inverted topography. Here we use high-resolution image and topographic data sets to investigate the morphology of these depositional systems and show key examples of their relationships to associated fluvial landforms. The inverted channel systems likely comprise indurated conglomerate, sandstone, and mudstone bodies, which form a multistory channel stratigraphy. The channel systems intersect local basins and indurated sedimentary mounds, which we interpret as paleolake deposits. Some inverted channels are located within erosional valley networks, which have regional and local catchments. Inverted channels are typically found in downslope sections of valley networks, sometimes at the margins of basins, and numerous different transition morphologies are observed. These relationships indicate a complex history of erosion and deposition, possibly controlled by changes in water or sediment flux, or base-level variation. Other inverted channel systems have no clear preserved catchment, likely lost due to regional resurfacing of upland areas. Sediment may have been transported through Arabia Terra toward the dichotomy and stored in local and regional-scale basins. Regional stratigraphic relations suggest these systems were active between the mid-Noachian and early Hesperian. The morphology of these systems is supportive of an early Mars climate, which was characterized by prolonged precipitation and runoff.