Field Exercises at the McCartys Flow, New Mexico: An Analog Site for Inflated Lava Flows on the Moon and Mars

The McCartys lava flow, located near Grants, NM along the Rio Grande Rift Zone, is an inflated, tube-fed, compound, basalt flow that extends for ~48-km from the cinder-cone source vent and offers an accessible field site for comparison with inflated lava flows on other planetary bodies. The overarching goal is to show the extent and complexity of lava flow emplacement associated with small volcanic vents from the ground perspective versus observations from remote sensing images and apply this to the interpretation of lava flows on other planetary bodies. Field objectives include: 1) traverse planning and navigation using satellite images and maps, 2) topographic data collection using Differential Global Positioning System (DGPS) and LIDAR, and 3) identification of different flow units and textures. Data sets available are: Landsat, Shuttle Radar Topography Mission (SRTM), topographic and geologic maps, plus web-based and software programs (Google Earth, TOPO!). Several data sets are available for the Moon (LO, Apollo, Clementine, KAGUYA) and Mars (THEMIS, CTX, MOC, HiRISE) over a range of resolutions. In the field, participants can: 1) plan a traverse to the vent source to document the morphology of the cinder cone using a DGPS and/or LIDAR, 2) identify ‘morphologic zones' in the remote sensing images and then identify these zone boundaries in the field, and 3) reconstruct the sequence of events and flow processes necessary to explain the observed stratigraphy at certain locations. Students can compare regional data sets to the field data to see the value and limitations (DGPS profiles versus SRTM profiles). The McCartys flow provides insight into the complexity of compound flows, the influence of inflation on modeling eruption parameters, and the development of volcanic fields from small volcanic vents, all of which provide a basis for comparison of volcanic processes between planetary bodies, particularly the Moon and Mars.