Precambrian rocks of the northern part of the Nacimiento uplift, New Mexico

The Nacimiento uplift bounds the central-eastern margin of the San Juan Basin and is the area of Precambrian exposure closest to the route covered by this field conference. Precambrian basement rocks have probably had a profound but subtle influence on the later geological development of the region; they are potential source rocks for mineral deposits (Woodward and others, 1974a; LaPoint, 1974) and have controlled some Cenozoic structures (Cordell, 1976).