A Noachian proglacial paleolake on Mars: Fluvial activity and lake formation within a closed-source drainage basin crater and implications for early Mars climate

TL;DR

This study identifies a well-preserved proglacial paleolake within a Noachian crater on Mars, suggesting early Mars had glacial activity that contributed to fluvial and lacustrine features, indicating a colder climate with glacial melting.

Contribution

It presents the first evidence of proglacial fluvial channels and lakes on Noachian Mars, expanding understanding of Mars' early climate and hydrological history.

Findings

Well-preserved inverted fluvial channels and lacustrine deposits inside a Martian crater.

Proglacial fluvial features likely formed from melting of a cold-based glacier.

First evidence of proglacial lakes on Noachian Mars.

Abstract

A 54-km diameter Noachian-aged crater in the southern highlands of Mars contains unusually well-preserved inverted fluvial channel networks and lacustrine deposits, all of which formed completely inside the crater. This closed-source drainage basin (CSDB) crater is distinct from previously documented fluvially breached or groundwater-fed crater basin lakes on Mars. We compare our observations to previously established models of crater degradation, fluvial incision, and topographic inversion on Mars to assess the most likely origins of the water that formed the fluvial and lacustrine features. We favor top-down melting of a cold-based glacier as the source of water in the CSDB crater, which would represent the first examples of proglacial fluvial channels and lakes found on Noachian Mars.