The Albuquerque Basin is one of the largest and deepest basins of the Rio Grande rift. The latest Oligocene to middle Pleistocene Santa Fe Group is the major basin fill unit. Paleogene deposits underlie the Santa Fe and indicate that a depositional center predated the Albuquerque Basin. Pre-Santa Fe Tertiary deposits are subdivided into a lower unit that is at least partly correlative with the Eocene Galisteo and Baca Formations and an upper unit, the unit of Isleta #2, that is equivalent to the Datil Group and the overlying sequence of Oligocene volcanic rocks. Thickness of the Santa Fe Group ranges from 1,000 to 2,000 m along the basin margins to as much as 4,407 m in the basin center. Galisteo and Baca thicknesses are as much as 454 m; the unit of Isleta #2 is up to 2,185 m in the Shell West Mesa well. Galisteo-Baca sediments were deposited in basins that predated the Albuquerque Basin. These depocenters continued to receive sediments of the unit of Isleta#2 during early to middle Oligocene time. Lower Santa Fe sediments (30 to 5 Ma) were deposited into two internally drained basins. After 10 Ma, the Santa Fe had filled the basins to the point where a single, internally drained Albuquerque Basin was formed. At about 5 Ma, the basin drainage became through-flowing with the development of the ancestral Rio Grande. The first major episode of Rio Grande Valley entrenchment at about 1.0 Ma ended Santa Fe deposition. Sedimentation rates ranged from 20 to 30 m/m.y. during early and late phases of Santa Fe deposition to as much as 600 m/m.y. during middle Miocene deposition.

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Santa Fe Group outcrops in the southwestern Albuquerque Basin occur in the Gabaldon badlands and Bobo Butte areas. Two oil test wells located near the Gabaldon badlands, the Humble Santa Fe Pacific #1 and Shell Santa Fe Pacific #2, penetrate the Santa Fe Group and pre-Santa Fe Tertiary deposits and bottom in Mesozoic bedrock.In the Gabaldon badlands, the thickness of the exposed Santa Fe Group is at least 1,138 m (3,732 ft) and may be as much as 1,800 m (6,000 ft). In the Humble Santa Fe Pacific #1 and Shell Santa Fe Pacific #2 wells, the Santa Fe thickness is 1,494 and 1,460 m (4,902 and 4,790 ft), respectively. The thickness of the exposed Santa Fe section at Bobo Butte is 246 m (807 ft). In the oil test wells, up to 1,097 m (3,600 ft) of pre-Santa Fe Group Tertiary deposits, which are correlative with possible Baca Formation and an unnamed post-Baca/pre-Santa Fe unit, underlie the Santa Fe Group. These pre--Santa Fe deposits indicate the presence of a depositional basin that predates the Albuquerque Basin.The Santa Fe Group exposed in the Gabaldon badlands area is divided into four units that correlate with the Popotosa Formation (units 1-3) and the Sierra Ladrones Formation. Units 1-3 of the Popotosa Formation were deposited in a closed-basin, distal-fan/basin-floor environment at a calculated sedimentation rate of 204 m/m.y. (669 ft/m.y.). The Sierra Ladrones Formation was deposited by a large, throughflowing, fluvial system and local alluvial-fan distributaries on adjacent piedmont slopes. Santa Fe Group deposits in the Bobo Butte area correlate with parts of the Popotosa Formation and were deposited in a proximal fan area. The caprock unit on Bobo Butte is probably correlative with at least part of the Sierra Ladrones Formation.Analysis of outcrop and thin-section data indicates that the Popotosa Formation in the southwestern Albuquerque Basin was derived from the Lucero uplift. At the time units 1-3 were deposited, the Lucero uplift was covered by at least one Tertiary ash-flow-tuff sheet and Upper Cretaceous strata. These rocks have since been eroded from the Lucero uplift and deposited in the southwestern Albuquerque Basin. The fluvial facies of the Sierra Ladrones Formation was at least partly derived from more distant source areas to the west and northwest. Outcrop data show that the caprock unit on Bobo Butte was derived from the Lucero uplift.Vertebrate fossils recovered from the Gabaldon badlands include Epicyon sp. cf. E. haydeni validus, Dipoides sp. cf. D. vallicula, Michenia sp. cf. M. yavapaiensis, and Plioceros sp. Fossils from units 2 and 3 indicate an early Hemphillian age (7-9 Ma), and the upper part of unit 1 is perhaps slightly older (latest Clarendonian).

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