Bell Regio, Venus: Integration of remote sensing data and terrestrial analogs for geologic analysis
The geology and surface morphology of Bell Regio (18-42 deg N, 32-58 deg E) are investigated using a combination of Magellan, Venera, and analogous terrestrial data. The properties of surface units are compared to either direct terrestrial analog measurements or to the behaviors predicted by theoretical models. Five major volcanic sources are identified from geologic mapping (Tepev Mons, Nefertiti corona, a large shield volcano east of Tepev, and two small edifices southeast of Tepev). The volcano Api Mons lies northeast of the main Bell uplift. The oldest volcanic units are associated with an extensive low shield volcano east of Tepev Mons and a small edifice southeast of Tepev. The annular flow apron of Tepev Mons formed next, with volcanism at a second small edifice on the southeast flank of Tepev Mons producing the youngest flow units. Comparisons between Magellan data, terrestrial radar images, and field topography profiles suggest that only three units resemble terrestrial a'a flows; the remainder are consistent with smoother pahoehoe-type surfaces. This suggests that most of the flow units were erupted at relatively low volume effusion rates (less than 100 cu m/sec) over long periods of time or had very low viscosities