Aeromagnetic Expression of Buried Basaltic Volcanoes Near Yucca Mountain

A high-resolution aeromagnetic survey has defined a number of small dipolar anomalies indicating the presence of magnetic bodies buried beneath the surface of Crater Flat and the Amargosa Desert. Results of potential-field modeling indicate that isolated, small-volume, highly magnetic bodies embedded within the alluvial deposits of both areas produce the anomalies. Their physical characteristics and the fact that they tend to be aligned along major structural trends provide strong support for the hypothesis that the anomalies reflect buried basaltic volcanic centers. Other, similar anomalies are identified as possible targets for further investigation. High-resolution gravity and ground-magnetic surveys, perhaps along with drilling sources of selected anomalies and radiometric age determinations, can provide valuable constraints in estimating potential volcanic hazard to the potential nuclear waste repository at Yucca Mountain.

Magnetic anomalies, Crater Flat basin and northern Amargosa Desert, Nevada. Colors represent magnetic field intensities relative to the International Geomagnetic Field (map created by R.J. Blakely, USGS); blue=negative magnetization, purple=positive magnetization. Letters identify anomalies
(O'Leary and others, 2002)

Reference:

O’Leary, D.W., Mankinen, E.A., Blakely, R.J., Langenheim, V.E., and Ponce, D.A., 2002, Aeromagnetic expression of buried basaltic volcanoes near Yucca Mountain, Nevada: U.S. Geological Survey Open-File Report 02-020.

More geophysical studies and data

U.S. Department of the Interior U.S. Geological Survey
URL: http://www.usgs.gov/default.asp
Page Contact Information: USGS Web
Page Last Modified: