Pennsylvanian Paleogeology and Search for Oil in Lucero Basin, Central New Mexico: ABSTRACT

Abstract

The Lucero basin of central New Mexico was an area of Pennsylvanian sedimentation representing a significant widening of the central New Mexico seaway or accessway from the Paradox geosyncline on the north to the Sonoran geosyncline on the south. Several such basins along this accessway include the Lucero, San Mateo, and Orogrande, all of which have slightly different post-depositional geologic histories. This accessway, of which the Lucero basin is a part, ranged from 50 to 130 miles in width, and received up to 3,000 feet of Pennsylvanian sediments which form the Sandia, Madera, and Red Tanks formations. This seaway was in existence between Atokan and Virgilian time but was widest during Desmoinesian and Missourian time. Pennsylvanian marine sedimentation was limited on the west by the Zuni positive, on the east by a long sinuous platform west of the Estancia basin and the Pedernal positive, and on the northeast by the Penasco positive. Fine clastic sediments from the Zuni and medium to coarse sediments from the Penasco make up less than one-fourth of the Pennsylvanian section which is predominantly limestone. The sharp downwarp of the Estancia basin on the east, as a southerly basin of the central Colorado-Sangre de Cristo seaway, resulted in entrapment of westerly moving coarse clastics from the Pedernal uplift. The Sandia-Manzanita-Manzano-Joyita tectonic alignment (of Tertiary age) was a long narrow platform or sill which separated the thick clastic-filled Pennsylvanian section of the Estancia basin from the somewhat thinner but normal basinal and shelf carbonate section of the Lucero basin. Bioherms grew on the gently shelving east sides of the central New Mexico accessway as indicated by outcrops of calcarenite mounds containing Chaetetes sp. corals in the Sandia and Manzano mountains. Inasmuch as the Pennsylvanian outcrops at Monte de Belen and Gray Mesa along the Lucero uplift show basinal lithologic character in Desmoinesian and early Missourian strata and the entire section thins to zero westward onto the Zuni positive, it is likely that similar reefoid masses will be found in the subsurface in the area surrounding the corner common to Catron-Socorro-Valencia counties. Because of Laramide folding and Tertiary faulting, the eastern two-thirds of the Pennsylvanian Lucero basin is buried deeply beneath the valley fill of the Rio Grande trench, and parts of the platform between the Estancia basin on the east and the Lucero basin on the west now stand high as the Sandia-Manzano block-fault mountains. End_of_Article - Last_Page 1108------------