Date of Award

2025-08-01

Degree Name

Master of Science

Department

Geology

Advisor(s)

Katherine A. Giles

Second Advisor

Benjamin Brunner

Abstract

This thesis investigates the origin and geologic context of dolostones associated with the Moab Valley salt wall in southeastern Utah, a feature within the broader Paradox Basin that offers an exceptional opportunity to study the interplay between carbonate sedimentation, diagenesis, and salt diapirism. The fundamental research question focuses on evaluating whether dolostones observed in the Moab Valley are all depositional, diagenetic or structurally reworked components of deeper stratigraphy, and how their presence and geometry relate to the halokinetic processes that shaped sedimentation across the Moab Valley. This study tested the hypothesis that dolostones within Moab Valley represent a mixed assemblage derived from various temporal and environmental origins, subsequently reconfigured by salt movement. Fieldwork, petrographic analysis, carbon and oxygen isotopes, and stratigraphic relationships are used to distinguish between carbonates formed in situ during deposition versus those mobilized (inclusions) or folded (megaflap) into younger strata via diapiric processes. Understanding the genesis of these dolostones provides important insights into the depositional and deformational history of the Moab Valley and the broader Paradox Basin. Beyond academic interest, accurately distinguishing between depositional and structural origins of such carbonates is critical. Misinterpretations can lead to flawed basin models, misdirected resource exploration, and incorrect assessments of CO2 sequestration potential. This research concludes that the dolostones in Moab Valley can be classified into 4 distinct lithofacies, each reflecting distinct depositional origins, ages, and relationships to the Moab Valley salt wall. These lithofacies represent three major episodes of carbonate formation in the Paradox Basin, driven by various combinations of glacio-eustatic, climatic, and diagenetic processes, as well as halokinetic influences. The Massive Silty Dolomudstone and Black Laminated Peloidal Dolomudstone lithofacies were deposited in the Pennsylvanian in the Paradox Formation layered evaporite sequence and subsequently dislocated and diapirically carried upward as non-evaporite inclusions in the Moab Valley Salt Wall. The Tan Laminated Sandy Dolomudstone lithofacies was deposited in a shallow hypersaline lake during deposition of the Triassic Chinle Formation. The Breccia Dolostone lithofacies formed post-Triassic in association with basinal fluid migration and diagenesis. Overall, the results support a model in which both depositional environments and salt-related structural processes must be considered together to accurately interpret carbonate occurrences near salt walls.

Language

en

Provenance

Received from ProQuest

File Size

105 p.

File Format

application/pdf

Rights Holder

Charles Ojodale Igomu

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Geology Commons

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