Explosive volcanism in the Tharsis region: Global evidence in the Martian geologic record

摘要: [1] A global equatorial set of layered deposits on Mars has been reexamined with Global Surveyor data. The stratigraphy, morphology, and erosional characteristics units separated by thousands kilometers are remarkably similar to each other consistent a widespread, episodic, subaerial source fine-grained material. This study is the first propose genetic link between many that have traditionally considered local or regional level, including Medusae Fossae Formation, Valles Marineris interior deposits, chaotic terrain, Terra Meridiani, Arabia materials. Mapping relationships suggest all these post-Noachian in age formation may continued until recent past. Thinning increasing distance from Tharsis rise suggests much materials be volcanic ash flows air fall explosive eruptions region, analogous those produced terrestrial plinian eruptions. Contemporary Martian winds would preferentially transport an eruption plume near east west along equator depending season. Erosion removed original ash, only isolated stacks remain, sometimes topographic depressions inhibit erosion. Modeling indicates widespread dispersion after easily attainable present past atmospheric conditions, hypothesis far-reaching composed vicinity Tharsis.