OF-96-04-21 Jemez Volcanic Field and Valles Caldera -- Middle Rio Grande Rift Download Publication Details Field trip no. 21 from “Geologic Excursions to the Rocky Mountains and Beyond,” field trip guidebook of the 1996 Annual Meeting of the Geological Society of America. (SP-44 has the complete set.) 16 pages. Digital PDF download. OF-96-04-21D From the Introduction: The intent of this three-day field trip is to provide an overview of volcanism of the Quaternary Valles caldera and the adjacent Pliocene Cerros del Rio volcanic field and to focus on new geologic, geochemical and geochronologic data related to the evolution of both. Citations Sawyer, David, and Ren A. Thompson. “OF-96-04-21 Field Trip Guide to the Quaternary Valles Caldera and Pliocene Cerros Del Rio Volcanic Field.” Fieldtrip. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1996.