San Juan Basin III (northwestern New Mexico)

About this guidebook

Welcome to the twenty-eighth consecutive Fall Field Conference of the New Mexico Geological Society. Each year seems to record some new milestone for the Society, and this year we have our first “camp-out” conference in the place where it all began, the San Juan Basin. The first day road log is from Farmington to Red Mountain Oil Field via Bisti, Crownpoint, Thoreau, Baca and Hospah. This route traverses the complete Upper Cretaceous, the Jurassic, and part of the Triassic systems between Farmington and Thoreau. From Thoreau we will pass eastward through the Triassic Chinle Formation to Baca, and from there northward back up the section to the top of the Mesaverde Group at the Red Mountain oil field. The second day road log is from Red Mountain Oil Field to El Vado Lake via Pueblo Pintado, Star Lake, Torreon, Cuba and Llaves. This route traverses parts of the south and east rims of the San Juan Basin. We will go from the Menefee Formation at Red Mountain up section through the San Jose Formation north of Cuba and then back down section to the Dakota Sandstone at El Vado Lake. The third day road log is from El Vado Lake to Farmington via Dulce, Lumberton and Chromo, Ignacio, Colorado, Navajo Dam and Aztec. We will travel more or less up section, going from the Cretaceous Burro Canyon-Dakota at El Vado to high up into the Eocene San Jose Formation near Ignacio, Colorado. We will see intrusive dikes near Dulce, the thinning wedge-ridge of the Mesaverde near Dyke, Colorado, and one of the prettiest surface structures anywhere, the Chromo anticline at Chromo, Colorado.