Upward-coarsening sandstone units of the Upper Cretaceous San Miguel Formation in South Texas were deposited in wave-dominated deltas during minor regressive phases, periodically interrupting a major marine transgression. Sediments accumulated in the Maverick Basin within the Rio Grande Embayment. Cross sections and sandstone maps reveal that during deposition of the San Miguel, the Maverick Basin consisted of two subbasins that received sediments from the northwest and the north.
Lower Permian (Wolfcampian) strata of the Palo Duro Basin consist of thick, terrigenous clastic and carbonate facies that were deposited in (1) fan-delta, (2) high-constructive delta, (3) carbonate shelf and shelf-margin, and (4) slope and basinal systems. Through Early Permian time, terrigenous detritus was eroded from surrounding highlands and transported by fluvial processes into the Palo Duro Basin.
The Neogene Ogallala Formation is an alluvial apron that occurs east of the Rocky Mountains from South Dakota to the Southern High Plains of Texas. The Ogallala was deposited by coalescent, low-gradient, wet alluvial fans that headed in mountains to the west. Geometry and depositional facies of the Ogallala Formation in Texas north of the 33rd parallel have been determined from outcrop studies and drillers' log descriptions.
The Catahoula Formation is composed of ancient fluvial sediments that controlled a wide range of water/sediment interactions responsible for uranium mobilization, transportation, and concentration.
Analysis during the second year was highlighted by a historical characterization of East Texas Basin infilling, the development of a model to explain the growth history of the domes, the continued studies of the Quaternary in East Texas, and a better understanding of the near-dome and regional hydrology of the basin. Each advancement represents a part of the larger integrated program addressing the critical problems of geologic and hydrologic stabilities of salt domes in the East Texas Basin.