Author: William C. McIntosh

Publisher:

Published: 1991

Total Pages: 84

ISBN-13:

This report presents 40Ar/39Ar sanidine ages and paleomagnetic data for 36 ignimbrites and associated lavas in the Eocene-Oligocene Mogollon-Datil volcanic field of southwestern New Mexico. 40Ar/39Ar age spectra from the ignimbrites yield plateau ages which range from 36.2 to 24.3 Ma and show within-sample and within-unit 1 s precision of ±0.5% or better. These ages agree closely with independently established stratigraphic order and indicate that Mogollon-Datil ignimbrite activity was highly episodic, being confined to four brief (