Electronic Theses and Dissertations

Date

2022

Document Type

Thesis

Degree Name

Master of Science

Department

Earth Sciences

Committee Chair

Daniel Larsen

Committee Member

William

Committee Member

Jackson, Dorian

Committee Member

Burnette

Abstract

Paleo-Lake Tecopa was one of many lakes in the southwestern United States during the Pleistocene (2.5 – 0.012 Ma), which were controlled by Milankovitch-driven climatic cyclicity. While most studies emphasize the basin-filling lakes of the middle Pleistocene, this study investigates the early Pleistocene lacustrine deposits interpreted to represent alternating playa/shallow lake conditions. Geologic mapping, stratigraphic analysis, and mineralogical assessment via X-ray diffraction shows a significant lake phase in the east-central basin from ~2.5 to ~1.7 Ma. During this time, periods of alternating shallow lacustrine and beach/nearshore facies may reflect the 41-kyr obliquity cycles characteristic of the early Pleistocene. Faulting, soft-sedimentary deformation, and missing stratigraphy in the east-central part of the basin suggests tectonically driven basin reorganization, affecting lacustrine expression. Because the oldest deposits of Lake Tecopa are exposed due to geologic structures and lack datable tephra, core studies would be needed to refine the temporal and spatial extent of this Plio-Pleistocene lake.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

Notes

Open Access

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