Seismic and Integrated Geophysical Study of the Lithosphere of the Colorado Plateau.

摘要

The major effort of this project was field data collection, data processing, and interpretation for the PACE (Pacific to Arizona Crustal Experiment) seismic experiment. This major cooperative study involved the University of Texas at El Paso, the Air Force Geophysical Lab, the U.S. and Canadian Geological Surveys, Stanford University, the University of Saskatchewan and the University of Arizona. The massive data set gathered during this experiment have been analyzed by a variety of techniques. The results show a gradual thickening of the crust from about 30 km in the Basin and Range to about 40 km along the southwestern margin of the Colorado Plateau. Lateral variations along the transition zone were found to be small. Work along a long profile extending from the Nevada Test Site to White Sands Missile Range included collection of new data, waveform modeling of data from the Albuquerque, NM digital seismograph station and a crustal structure study of western New Mexico. These results document thin (approximately 35 km) crust beneath the central portion of the Rio Grande rift, extension of the lithospheric anomaly associated with this rift well east of the physiographic rift valley a broad transitional zone to thick crust on the western margin of the rift, and delineation of a batholithic mass in the upper crust of western New Mexico.