Geophysics of Rio Grande Basins
August 2009 - Release of a high-resolution aeromagnetic survey to image shallow faults, Poncha Springs and vicinity, Chaffee County, Colorado as USGS Open-File Report 2009-1156.
High-resolution aeromagnetic data were acquired over the town of Poncha Springs and areas to the northwest to image faults, especially where they are concealed. Because this area has known hot springs, faults or fault intersections at depth can provide pathways for upward migration of geothermal fluids or concentrate fracturing that enhances permeability. Thus, mapping concealed faults provides a focus for follow-up geothermal studies.
May 2009 - Great Sand Dunes aeromagnetic survey released as USGS Open-File Report 2009-1089.
A high-resolution aeromagnetic survey was flown in October 2008 over the Great Sand Dunes by Upper Limit Aviation, Inc., for New Sense Geophysics, Ltd., on contract to the U.S. Geological Survey (USGS). The survey covers a large part of Great Sand Dunes National Park and Preserve (GRSA) and extends south along the mountain front to the foot of Blanca Peak (fig. 1). Scientific objectives for the Great Sand Dunes survey are to investigate the subsurface structural framework that may influence ground-water hydrology, seismic hazards, or geothermal resources. Funding was provided by the USGS, National Park Service, and Colorado Geological Survey. The southern portion of this survey area connects with high-resolution aeromagnetic surveys flown previously in the southern San Luis basin.
May 2009 - Release of a comprehensive paper on geophysical interpretations of the southern Española basin, New Mexico, that contribute to understanding its hydrogeologic framework: USGS Professional Paper 1761.
The southern Española Basin consists of a wedge of rift fill, primarily of Santa Fe Group sediments, that serves as the principal aquifer for the city of Santa Fe. This report synthesizes interpretations from detailed aeromagnetic surveys and gravity data, using other constraints. The results depict details of many geologic features of hydrogeologic significance such as shallow faults, different types of igneous units, and basement rocks.