Rio Grande Rift: El Paso, Texas to Denver, Colorado, July 20 – 30, 1989

Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 138.It was only in the 1970s that the Rio Grande rift came to be recognized as a coherent tectonic feature which was more than simply an arm of the Basin and Range province (e.g., Chapin, 1971, 1988; Decker and Smithson, 1975; Cordell, 1978). The international scientific community was largely unaware of this feature until an international rift conference was convened in Santa Fe, New Mexico, in the fall of 1978. The volume published as a result of this conference (Riecker, 1979) established the Rio Grande rift as an important Cenozoic Continental rift, and the guidebook produced for this conference (Hawley, 1978) is the basis of this field trip. Although many questions remain, the many studies conducted since 1978 provide an improved picture of the nature and evolution of this rift which extends from northern Colorado into northern Mexico and is superficially similar to the Kenyan arm of the East African rift (Fig. 1). The discussions which follow are intended to augment the papers in Riecker (1979) and briefly review results obtained since its publication. Other recent volumes on the rift include a special section of the Journal of Geophysical Research (May 1986), New Mexico Geological Society Guidebooks for the 1979, 1980, 1982, 1983, 1984, and 1986 field conferences, and field trip guides by Gile et al. (1981), McLemore and Bowie (1987), and Menges (1987).