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EP: Extraterrestrische Physik
EP 5: Planeten und Monde
EP 5.6: Vortrag
Dienstag, 19. März 2002, 17:10–17:25, HS 15
Middle-Late Amazonian Plains Volcanism in Tempe Terra, Mars — •Ernst Hauber1, Peter Kronberg2, Ursula Wolf1, and Gerhard Neukum1 — 1Institut für Weltraumsensorik und Planetenerkundung, DLR, Rutherfordstr. 2, 12489 Berlin — 2Institut für Geologie und Paläontologie, TU Clausthal, Leibnizstr. 10, 38678 Clausthal-Zellerfeld
The Tempe Volcanic Province (TVP) on Mars is characterized by low shields, cones, sheet flows, pit craters, maars, rift zones, and grabens. We investigate its topography, morphology, and age. Our morphometric measurements confirm earlier suggestions that the TVP is directly comparable to terrestrial plains volcanism as observed in the Snake River Plains. In addition, we find surface features (lava tubes, sinuous rilles, cinder cones) which have not been noted in the TVP before. We map lava flows in Viking images and measure their impact crater density. We derive absolute crater model ages between 1.1 Ga and 0.5 Ga, corresponding to Middle-Late Amazonian. We also measure crater density in high resolution MOC images: A model age of 0.9 Ga is consistent with the Viking-based ages. The results suggest that the TVP formed over an extended period relatively late in Martian history. Morphologically, the TVP resembles basaltic volcanic fields (VF) on Earth. Terrestrial VF are often associated with hot spots. Even small VF are assumed to be fed by plumes, and recent work argues for a large number of small plumes on Earth. In analogy, a diffuse mantle upwelling on top of a hotspot with low rates of magma supply meeting a previously weakened lithosphere could have contributed to the formation of the TVP.