Unique curvilinear ridges in the Qaidam Basin, NW China: Implications for martian fluvial ridges

Abstract

Curvilinear ridges are extensively identified on the surface of terrestrial planets and can be formed by volcanic, glacial, eolian, or fluvial processes. In the Qaidam Basin, NW China, a set of unique curvilinear ridges that have similar appearances as inverted channels but are dominated by sand deposits in their interiors has been identified. To reveal its formation mechanism, we analyzed their topography, morphology, outcrop and profile characteristics by remote-sensing and field surveys. We proposed that these curvilinear ridges are “sand-infilled inverted channels” formed by episodic wet and dry climate transitions. Considering the long history of Mars, some martian curvilinear ridges could also be formed by this mechanism, thus we should be more cautious in the identification and analysis of martian inverted channels. In addition, the occurrence of sand-infilled inverted channels on Mars may imply that the martian climate change from warm and wet to cold and dry has been gradual rather than abrupt, once this kind of inverted channels found on Mars.