Interpretation of a seismic profile extending 548 km southward from the GASBUGGY nuclear test of December 10, 1967 resulted in a crustal model for central New Mexico. The crust is 39.9 km thick below the Paleozoic “basement”. It consists of an upper crust 18.6 km thick having P velocity 6.15 km/sec, and a lower crust 21.3 km thick having P velocity 6.5 km/sec. The apparent upper mantle velocity is 8.12 km/sec. This model applies near the crossover distance, 50 km west of Albuquerque. Additional information from earthquakes and explosions suggests that the upper crustal velocity drops to 5.8 km/sec in the Rio Grande rift, and that the true upper mantle velocity is 7.9 km/sec. The low upper crustal velocity in the Rio Grande rift can be detected on the record section of the GASBUGGY profile.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.