Karst Landforms in a Martian Evaporitic Dome

Abstract

The Tithonium Chasma is the northern trench of the western troughs of Valles Marineris (Mars). In the eastern part of the canyon system a mountain displaying a dome shape morphology is located. According to OMEGA mineralogical data (OMEGA data orbit 531_3) and further studies the dome appears to consist of magnesium sulphate (kieserite), an evaporitic mineral also found on the Earth. Previous works highlighted the presence of karst-like landforms and morphologies that strongly resemble the evaporitic karst morphologies found on the Earth. Through the analysis of the new MRO HiRISE images we have investigated the Martian landform and the possible processes involved in their formation and shaping in great detail. The analysis carried out show that the landforms observed clearly indicate the presence of solutional processes that also acted in a selective way, highlighting that the Martian dome can be formed of dfferent materials (minerals, grain-size, ect.) with different solutional properties. The results of our observation also suggest that on the dome liquid water must have existed in the past for enough time so that the solution features we investigated could be formed.