FIELD CONSTRAINTS ON REMOTE SENSING SHIELD VOLCANO INTERPRETATIONS: QUANTITATIVE CONSTRAINTS FROM THE SNAKE RIVER PLAINS AND EXTENSIONS TO MARS

The eastern Snake River Plain (ESRP) volcanism features of Idaho have often been suggested as analogs for a range of Martian volcanic features. The Mars Orbiter Laser Altimeter data has revealed more flow, shield, and small edifice features than were previously mapped from images alone, and Mars Orbiter Camera and Thermal Emission Spectrometer images have helped expand the identification of volcanic features and confirmed the volcanic nature of many features identified in the topography. This study both maps features and characterizes their topographic parameters to constrain the probable eruption style(s) and thus the emplacement mechanics of the small edifices. Prior work in this study has shown that GPS field unit topographic profiles of Quaternary ESRP monogenetic shield volcanoes combined with geochemical sampling may help infer compositional changes in magma supply. In the ESRP, shields with steep summit regions (“caps”) show that magmatic compositions are likely more evolved than those at simple shields with consistently low angle flanks. We have been sampling the topography of the ESRP shields at field sampling rates (data points per shield diameter) similar to those available in MOLA topography for the larger Martian edifices, and noting that Martian edifices in some regions also display shields with steep summit regions mixed among the low slope shields, as well as a mix of other features similar to those found in the ESRP such as cinder cones, tuff rings, flow fields, lava tubes, etc… Martian fields display different clusters of topographic characteristics while still fitting into several global parameter trends as well, and it seems plausible that some of the local variations as well as the global trends might be constrained with robust terrestrial ESRP field analogs between geochemistry and topography