Abstract of paper presented at American Geophysical
Union 1982 Fall Meeting,
San Francisco, California.
Trans. American Geophysical Union (Eos), v. 63, p. 913.
A paleomagnetic investigation of Miocene volcanic rocks, Yuma Co., Arizona
M. Veseth, J. E. Butterworth, M. Marshall, Dept. of Geological Sciences, San Diego State University, San Diego, CA
Miocene volcanic rocks from the Plumosa, New Water, Kofa, and Castle Dome Mountains in central Yuma Co., SW Arizona were sampled in order to detect any rotations or large translations associated with either detachment or strike slip faulting. Forty flows were collected at fifteen localities and consist of ten early-mid Miocene tuffs and thirty late Miocene basalts. The tuffs apparently overlie and were probably erupted before or concurrent with the widespread detachment fault in this area. The basalts dip gently or are flat lying and presumably affected only by basin and range and possibly strike-slip faulting. The declination values of both rock types suggest that no statistically significant rotations have occurred in this area during detachment or later faulting. Despite a large amount of scatter in the site directions the inclination values are almost all too shallow and suggest an average northward translation of 8°. While probably not statistically significant this value is similar to that found in most other paleomagnetic studies closer to the western margin of California and Baja California.