Lava filling of Gale crater from Tyrrhenus Mons on Mars

Abstract

Gale crater shows infilling of lava of basaltic origin mainly coming from the south via Farah Vallis. Using available Thermal Emission Imaging System (THEMIS) images, Mars Orbiter Laser Altimeter (MOLA) topographic data, Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) mineralogical data, and geochemical analyses taken in situ by the Mars Science Laboratory (MSL) in different locations of the crater, we focused on the possible origin and the main path of the lava that filled Gale crater. We found that: 1) the K/Ar age of the basaltic rocks on Gale's floor is consistent with the age of formation of Tyrrhenus Mons derived from the southern polar giant impact (SPGI) model; 2) the Aeolis Mensae region does not show evidence for interaction between lava coming from the north (Elysium Mons) and lava coming from the south (Tyrrhenus Mons); 3) the geomorphological analysis shows that Farah Vallis is the convergence of a complex network of volcanic channels that can be tracked back to the lava fields of Tyrrhenus Mons; 4) a one-dimensional model of lava along the observed path, using an Adirondrack basalt composition for the substrate, shows that lava from Tyrrhenus Mons is thermally capable of flowing the entire distance to Gale before cooling down. This evidence is consistent with the lava fill observed at Gusev crater.