A new terrestrial analogue site for Mars research: The Qaidam Basin, Tibetan Plateau (NW China)

Abstract

Remote sensing observations and rover missions have documented the presence of playas, salts, and wind erosion landforms of lacustrine sediments on Mars. All of these observations suggest Mars was aqueous in its early history. However, abundant questions remain: How wet was the environment, what were the properties of the liquids and the possibility of ancient habitability, and what kinds of geological processes shaped the present landforms? To explore these unknowns, analogue studies can play a key role. In this contribution, we introduce the Qaidam Basin, Tibetan Plateau, northwestern China as a new and unique analogue site for studying the past aqueous and present arid environments of Mars. The Qaidam Basin, the highest and one of the largest and driest deserts on Earth, is located in a dry, cold, and high UV environment, similar to the surface of Mars. We demonstrate a variety of landforms and also their counterparts on Mars, which include aeolian dunes and yardangs, polygons, gullies, valleys, and fluvial fans. In the Qaidam Basin, various environmental regimes for the formation of linear and asymmetric barchans have been described. Saline lakes and playas representing different stages of lake evolution in arid environment are also present in the Qaidam Basin and provide promising cases for studying the habitability in Mars-like environments. Results for microorganism isolation suggest that halophiles are the most important fraction in the hypersaline sediments and this may shed light on studying present Martian habitability. Moreover, the remote but ready accessibility of the Qaidam Basin make it a potential site for engineering testing in regards to future martin exploration missions. We propose that the variety of exogenic and endogenic geomorphic types, lacustrine sediments, evaporite mineral assemblages and Mars-like extreme environments collectively point to the Qaidam Basin as an optimal