Morphology and geology of an interior layered deposit in the western Tithonium Chasma, Mars

• A dome-shaped ILD in Tithonium Chasma displays areas with signatures of kieserite.
• The dome displays features that were formed by liquid water released from melting ice.
• The surface of the dome has few impact craters, suggesting its relatively young age.
• The characteristics of the dome suggest that it was emplaced as a diapir.

This paper describes a morphologic and morphometric survey of a 3.1 km-high, domeshaped upland in western Tithonium Chasma (TC) which coincides with areas containing abundant surface signatures of the sulphate mineral kiersite, as identified by the OMEGA image spectrometer. The morphologic features of the dome were investigated through an integrated analysis of the available Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE), Mars Orbiter Camera, and Context Camera data, while the morphometric characteristics of the structure were measured using a topographic map (25-m contour interval) built from high-resolution stereo camera (HRSC) and Mars Orbiter Laser Altimeter (MOLA) data.The dome displays surface features that were apparently formed by liquid water probably released from melting ice. These features include karst landforms as well as erosive and depositional landforms. The surface of the dome has few impact craters, which suggests a relatively young age for the dome. Layers in the dome appear laterally continuous and are visibly dipping toward the slopes in some places.The mineralogical and structural characteristics of the dome suggest that it was emplaced as a diapir, similar to the dome structure located in the eastern part of TC, and to many salt diapirs on Earth.