Cenozoic basin-fill stratigraphy and depositional history of the Albuquerque Basin, central New Mexico

The Albuquerque basin is composed of a northern. eastward-tilted half-graben and a southern. westward-tilted half-graben. A southward extension of the Tijeras fault appears to mark the boundary between the half-grabens. Latest Oligocene to middle Pleislocene Santa Fe Group deposits are the major syn-rift unit of the basin. Thickness of the Santa Fe Group ranges from 1000 to 2000 m along basin margins to as much as 4407 no in the central basin. Underlying the Santa Fe Group are two units that generally correlate with the Galisteo-Baca formations and the Datil Group. They range in age from Eocene to late Oligocene and indicate the presence of at least two basins that pre-date the Albuquerque basin. Thicknesses of these units are up to 3000 m.

 

Cenozoic deposition in the Albuquerque basin area began in the Eucene when Galisteo-Baca sediments were deposited into the Galisteo- El Rho and Carthage-La Joya basins. These basins continued to receive sediments (the unit of lsleta #2) during the Oligocene. Early Santa Fe Group sedimentation 130- IS my) occurred in two internally-drained basins that correspond to the half-grabens. After 10 my. Santa Fe sediments had tilled to the point where a single. internally-drained Albuquerque basin was formed. At about 5 my. the basin drainage shifted to through-flowing with the development of the ancestral Rio Grande. The first major episode of Rio Grande entrenchment at about U.S my ended Santa Fe Group deposition.