New Mexico Geological Society Annual Spring Meeting — Abstracts

A circular feature located in the Jornada del Muerto valley in southern New Mexico, visible only on satellite photographs, has been interpreted to be a meteor-impact crater. The crater has a diameter of about 8-miles and an area of 50 square miles. It is accessible via Sierra County Road No. 013 that splits the middle of the crater and follows the route of the historic 1598 Camino Real. The crater’s surface has a gentle slope of 3.5 to 0.7 % on the east side of the Caballo Mountains. The crater edge stands out in aerial/satellite photos as a consequence of the dense band of vegetation that highlights at least 60 % of the crater’s perimeter. This band of vegetation is probably a result of the groundwater-boundary conditions that may have caused dissolution of the broken Permian limestone strata at depth at the interface and subsequent local depressions. Magnetometer surveys across the vegetation-marked edges indicate a disturbed, mega-breccia bedrock in lateral contact with apparently uniform crater-fill deposits. The impact may have occurred at (or near) the end of deposition of the Mesaverde Formation in the southern part of the Western Interior Seaway establishing a maximum age. The Paleocene alluvial fan deposits of the Laramide Love Ranch Formation, that overlie the crater’s footprint and probably partially fill the crater, establish a probable minimum age that is near the K/T boundary or about 65.5 Ma. It is unlikely that iridium or shocked quartz will be found on the surface.