The Origins of Four Paterae of Malea Planum, Mars The Origins of Four Paterae of Malea Planum, Mars
The geology of the Malea Planum Region has been influenced by impact cratering, volcanic, tectonic, fluvial, and most recently, eolian processes. The Noachian was dominated by impact cratering, the formation of Hellas Basin, and the eruption of flood lavas. Malea Planum formed during the mid- to late-Noachian, likely the result of sills liquefying the volatile-rich crust. Malea and Pityusa Paterae formed during the late Noachian. The Hesperian was marked by the formation of Peneus and Amphitrites and complex valley networks. During the mid-Hesperian, southern Malea Planum may have been covered by a very thick polar mantle deposit that melted and sublimated during the late Hesperian. Smaller episodes of polar mantle deposition continued through the Amazonian to the present. The Amazonian is also characterized by eolian activity creating dune fields, etched surfaces, and dust devil tracks.
Based on the topographic and geophysical evidence, Amphitrites and Peneus are typical highland paterae. We conclude that a mid-crustal sill complex similar to that thought to exist beneath the eastern Snake River Plain in Idaho may be the best explanation for the formation of Malea and Pityusa Paterae. A lack of associated flow features on the surface suggests that the loads are the result of an accumulation of dense intrusions. A surficial load (e.g., lava flows) is insufficient to cause the amount of subsidence observed. A mid-crustal mafic or ultra-mafic sill or a dense network of sills and dikes may have contributed to the subsidence.
School:Brigham Young University
School Location:USA - Utah
Source Type:Master's Thesis
Keywords:malea planum amphitrites peneus pityusa hellas planitia mars patera caldera volcano mantle polar corona crater counts gravity viking themis global surveyor orbiter camera mola
Date of Publication:12/19/2006