GIS AND REMOTE SENSING APPLIED TO THE QUATERNARY POTRILLO VOLCANIC FIELD, SOUTHERN RIO GRANDE RIFT

Studies of the alkaline mafic Potrillo volcanic field (PVF) in the southern Rio Grande rift have resulted in robust datasets for geochemistry and geochronology used to produce a magma dynamics model (Williams, 1999). 3He cosmogenic dating revealed that volcanic activity was not continuous throughout its ~1 Ma - 20 ka history. Rather, there has been punctuated activity with frequent shifts of foci and some reoccupation of edifices after 50 ka upwards to 100 ka of quiescence. Our current study uses geographic information systems and remote sensing techniques that include Enhanced Thematic Mapper Plus (ETM+) and Advanced Space-borne Thermal Emission Reflectance Radiometer (ASTER) integration along with Digital Elevation Model (DEM) analyses. Small volume basaltic centers such as found in the Potrillo volcanic field display a broad range of morphologic features, with several similar to those interpreted from the Mars Orbital Laser Altimeter (MOLA) topographic data: shields, flows (lava-tube and fissure-fed), and potential hydromagmatic forms. A better understanding of Mars planetary volcanism can be gained through terrestrial analog studies that integrate remote sensing, temporal, geochemical, and geologic spatial information. Therefore, presented are observations made during this undergraduate thesis study for use of the PVF as a terrestrial analog with Mars. For example, are there maars on Mars? One objective of this project is to map the Potrillo volcanic field in greater topographic detail in order to compare with Mars Orbiter Laser Altimer (MOLA) images. Our maps show the PVF in hillshade with contours applied and are used to make profiles across several features, such as Kilbourne Hole (maar with tuff ring) and Black Mountain (scoria cone). Three-dimensional images made show the relief and distribution of volcanic deposits. Further, GIS layers using attribute tables are preliminarily fused with remote sensing data. This is done to provide digital spatial information for future studies involving the Potrillo volcanic field using a more "geoinformatics" approach. REF: Williams, W.J.W. (1999), Evol of Quat Intraplate Mafic Lavas Det using 3He Surf Expo and 40Ar/39Ar dating, and Elem and He, Sr, Nd, and Pb Iso Sig, Dis, Univ of Texas at El Paso, 195 pp.