Date of Award
1-1-2024
Document Type
Dissertation
Degree Name
Ph.D. in Engineering Science
First Advisor
Robert M. Holt
Second Advisor
Jennifer N. Gifford
Third Advisor
Brian F. Platt
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
The northern Delaware Basin in southeast New Mexico recorded the deposition of thick evaporite beds followed by siliciclastic materials between the late Permian and Early Triassic. Mineralogy and whole-rock geochemistry of the bioturbated zone and the first mudstone/halite (M1/H1) informal units in the Los Medaños Member (Rustler Formation) suggest felsic volcanic arc origins for the bioturbated zone and felsic upper continental crust passive margin origins for the M1/H1. The previously studied marine transgression that deposited the bioturbated zone likely transported detritus from southern North America and Central American volcanic arcs into the northern Delaware Basin, whereas the regression allowed migration of continental detrital sediments from the basin surroundings into the depocenter. The petrography and mineralogy of the Permo-Triassic Dewey Lake sandstones indicate a general decrease in clay content upward and a predominance of relatively coarser grains in the upper Dewey Lake, consistent with the change of environment from mudflat to floodplain from previous studies. Detrital zircon (DZ) U-Pb geochronology of sediments in the upper Permian Salado and Rustler, and in the Permo-Triassic Dewey Lake white sandstones indicates primary sediment sources of the upper Permian formations to be the Marathon-Ouachita orogenic system and Central American peri-Gondwanan/Gondwana terranes, similar to other studies in the middle Permian Formations in the Delaware Basin. The Dewey Lake white sandstones consist essentially of Laurentian basement material probably sourced from recycled sediments in Ancestral Rocky Mountains basins. The DZ geochronology also reveals a source change between the deposition of middle-upper Permian sediments and Permo-Triassic white sandstones in the Dewey Lake. Salt ridges present in the northern Delaware Basin began to deform during the late Permian, based on syn-depositional deformation evidence in the Rustler, as opposed to previous estimates that interpreted deformation as occurring during the post-Late Triassic and mid-Cenozoic. Salt ridges likely continued to deform during the deposition of Upper Triassic Santa Rosa Formation. The study of sediment origins, dispersal pathways and timing of salt deformation in the northern Delaware Basin contributes to the scientific understanding of the dynamic history of the Delaware Basin and sets the stage for further detailed work.
Recommended Citation
Akakpo, Omonde Sitou, "Time and Space Evolution of Late Permian to Early Triassic Deposits in the Northern Delaware Basin, Southeast New Mexico, U.S.A.: Sediment Sources, Dispersal Pathways, and Timing of Salt Deformation" (2024). Electronic Theses and Dissertations. 2997.
https://egrove.olemiss.edu/etd/2997
