New paper on the geologic evolution of the San Juan Basin

This research, published on-line by Geosphere, describes the Laramide (Late Cretaceous to Eocene) fluvial evolution of the San Juan Basin of northwestern New Mexico. It focuses primarily on the Paleocene Nacimiento and Animas formations, using paleocurrent analysis and ⁴⁰Ar/³⁹Ar geochronology. The paper shows the Laramide fluvial evolution was complex and responded primarily to variations in subsidence rates within the basin.

The authors are Steve Cather (recently retired Bureau Field Geologist), Matt Heizler (Bureau geochronologist), and Tom Williamson (paleontologist at the New Mexico Museum of Natural History and Science).