New Mexico Geological Society Annual Spring Meeting — Abstracts

Land-based Gravity and Magnetic data were obtained at 56 gravity and 250 magnetic stations throughout the northern to central Galisteo Basin south of Santa Fe, NM. The study area extends south from the village of Eldorado to the foothills of the Ortiz Mountains and east from I-25 to Highway 285; an area of approximately 3600 km² . These data provide a novel approach in subsurface investigations by integrating surface geological mapping and subsurface geophysical surveys to characterize the geometry, distribution, depth, and potential hydrocarbon trap geometries in parts of the Galisteo Basin in 2.5D using the Talwani and GravMag geophysical modeling softwares and field exploration methods. The structurally complex nature of the Galisteo Basin provides an excellent location for stratigraphic and structural trap exploration using geophysical methods due to the density and susceptibility contrasts between the various Formations within the basin. Gravity and magnetic data were modeled along several regional profiles on selected parts of the Galisteo Basin, combined with surface geologic information, to constrain the nature of the subsurface. Both sets of potential field data were integrated into ArcGIS 9.3 and Surfer 8.0 to generate extrapolated surfaces and derivative maps which allowed for the characterization of the subsurface geology along specific profiles across the mapped area. These data reveal that several anomalies exist within the central portion of the basin which we interpret as likely hydrocarbon trap-structures. In order to investigate the possible geometries of the anomalies, detailed forward models are being developed to assess possible trap structures, extent, and distribution within the basin. These data should allow us to estimate the hydrocarbon potential within select parts of the basin and provide an estimate of reserves present.