Bulletin 56—Geology and mineral resources of Mesa Del Oro Quadrangle, Socorro and Valencia (now Cibola) Counties, New Mexico

By H. L. Jicha, Jr., 1958, 67 pp, 12 tables, 2 figs., 5 plates, 1 index. Mesa del Oro quadrangle is located about 40 mi southwest of Albuquerque and 26 mi west of Belen, in central NM.

Mesa del Oro quadrangle is located about 40 miles southwest of Albuquerque and 26 miles west of Belen, in central New Mexico. The topography of the area is varied, and elevations range from about 6,000 to 7,500 feet.

The quadrangle is on the west flank of the Lucero uplift, a westward dipping monoclinal structure that forms the east boundary of the Acoma embayment of the San Juan Basin. The quadrangle is obliquely transected by Sierra Lucero, a northeastward trending, northwest-dipping expression of the structural high formed by the Lucero uplift. The east margin of Sierra Lucero is a steep cliff, in which the upper part of the Lower Permian sequence (Glorieta and San Andres formations) forms a broad valley (Los Vallos) east of the escarpment. The dip slope is composed of resistant Permian limestones (San Andres formation), capped at places by Triassic red beds (Chinle formation) and Tertiary lava flows. Locally northwest-striking, high-angle normal faults cut the western margin of the Sierra Lucero. Sodaclase-diorite dikes parallel the strike of the faults, and sills of similar composition intrude the Permian and Triassic rocks in the eastern half of the quadrangle. In the southwestern part of the area, a series of small anticlinal folds occurs. The northwestern part of the quadrangle is typical of the Acoma embayment of the San Juan Basin. The dips are low and typically to the west and north. The region is dotted by scattered basaltic lava flows and plugs. Many of the flows cap remnants of Cenozoic erosion surfaces cut on Triassic rocks, forming broad mesas, some of which cover areas of considerable size. At a few places in the southern and northwestern parts of the quadrangle, Upper Cretaceous rocks (Dakota?, Mancos, and Mesaverde) are exposed. Jurassic rocks (Entrada, Summerville?, and Morrison formations) occur only in the northwestern corner of the area.

Water resources of the area are meager, and the water is generally of poor quality. The oil and gas possibilities have never been tested fully. The most important mineral resource is high-calcium lime rock (travertine), a large deposit of which occurs on the north end of Mesa del Oro. Other potential resources are gypsum, flagstone, and basalt blocks. No metallic deposits are known to occur in the area.