Gorgonum Chaos is part of the Eridania paleolake in Terra Sirenum and displays a number of prominent light-toned morphological features that bear a record of the regional climatic conditions throughout most of Martian history. Based on an intergrated analysis of orbital data, we mapped a 1,500 km² area in the southeast of Gorgonum Chaos. Morphologic, spectroscopic, and stratigraphic analyses were used to determine age and composition of the main geological units in the area. We identified four major geological units with decreasing content of hydrated minerals from the oldest to the youngest units, which were completely free of hydrated minerals. In the study area, phyllosilicate-rich Noachian units compose the majority of the basin floor. Deposits enriched with evaporites were formed around the Noachian/Hesperian transition and erosion created prominent inverted morphologies. Loess-like material without significant amounts of hydrated minerals was deposited until the late Hesperian. The youngest unit is an Amazonian layer free of hydrated minerals that originated from volcanic activities. This succession of minerals reflects the transition from more humid climatic conditions with the ability to sustain liquid water on the planet's surface during the Noachian to the hyper-arid Amazonian environment we observe currently on Mars.

中文翻译：

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东南戈耳戈努姆混沌地质史，火星：水与风的故事

Gorgonum Chaos 是 Terra Sirenum 的 Eridania 古湖的一部分，显示出许多突出的浅色调形态特征，记录了整个火星历史上大部分地区的气候条件。基于对轨道数据的综合分析，我们绘制了 1,500 km ²戈尔戈努姆混沌东南方区域。形态、光谱和地层分析被用来确定该地区主要地质单元的年龄和组成。我们确定了四个主要的地质单元，从最古老的单元到最年轻的单元，水合矿物的含量逐渐减少，这些单元完全没有水合矿物。在研究区，富含页硅酸盐的诺亚阶单元构成了盆地底部的大部分。在 Noachian/Hesperian 过渡区周围形成了富含蒸发岩的沉积物，侵蚀形成了突出的倒转形态。没有大量水合矿物的类黄土物质一直沉积到晚西伯利亚。最年轻的单元是亚马逊层，不含源自火山活动的水合矿物质。