Discussion of new gravity maps for the Albuquerque Basin area
V. J. S. Grauch, Cindy L. Gillepsie, and G. R. Keller
Gravity data recently acquired to fill in a large gap in data coverage in the southwestern part of the Albuquerque basin are combined with older data to produce new Bouguer and isostatic residual gravity maps of the Albuquerque basin area. The new maps show three subbasins within the Albuquerque basin that are separated by northwest- and/or north-trending gravity highs. The configuration of the subbasins do not support a master "Rio Grande fault," which was previously proposed for the eastern margin of the Albuquerque basin based on seismic-reflection data. North–south-trending gravity gradients are similar to others in the region that may be related to strike-slip faults located along weaknesses developed during Precambrian time. Northwest gravity trends in the central part of the basin may reflect buried rift-related structures that are older than northstriking faults conspicuous at the surface. Northeast-trending accommodation zones are not apparent in the gravity maps. A gravity low in the southeastern part of the Albuquerque basin cannot be explained by thick basin fill, because the Grober-Fuqua deep oil exploration well indicates significantly thinner fill in the area of the low. Simple profile models were developed to test three different explanations for the gravity low. The only model that fits both gravity and drill-hole evidence is conceived as a buried, late Paleozoic(?) basin containing a significant amount of salt. Such a hypothesis is not unreasonable for this area, but more subsurface information should be acquired to verify the hypothesis.
- Grauch, V. J. S.; Gillepsie, Cindy L.; Keller, G. R., 1999, Discussion of new gravity maps for the Albuquerque Basin area, in: Albuquerque Country, Pazzaglia, Frank J.; Lucas, S. G.; Austin, G. S., New Mexico Geological Society, Guidebook, 50th Field Conference, pp. 119-124.