Los Angeles: The most differentiated basaltic martian meteorite. Alan E. Rubin et al.
Los Angeles is a new martian meteorite. It is a type of igneous rock called basaltic shergottite, formed from volcanic lava flows on Mars. As the parent magma cooled and minerals crystallized, the remaining liquid became richer in iron, phosphorus, and other elements that do not readily partition into early crystallizing phases. Among the 16 known martian meteorites, Los Angeles is by far the most enriched in iron, phosphorus, and many trace elements, and is the most depleted in some other trace elements such as chromium. The mineralogical characteristics of pyroxene in this meteorite imply that the parent rock cooled more slowly than other basaltic shergottites and thus may have been more deeply buried. Like other martian meteorites, Los Angeles was intensely shocked (transforming the major mineral plagioclase into a rare plagioclase-composition glass called maskelynite) as it was launched into space by a meteoritic impact that blasted the surface of Mars.
Numerical simulations of glacial-valley longitudinal profile evolution. K.R. MacGregor et al.
Valley glaciers are very important in shaping mountainous landscapes. They broaden valley bottoms and produce the classic U-shaped valley cross section. In addition, glaciers can enhance local valley relief, generate multiple steps and overdeepenings of valley floors, and they cause tributary valleys to hang
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