Date of Award
5-1-2026
Degree Name
Master of Science
Department
Geology
First Advisor
Potter-McIntyre, Sally
Abstract
Polygonal impact craters (PICs) have reemerged as a prominent topic in planetary studies, particularly those involving global tectonic patterns. PICs are craters that contain at least two straight rim segments, which commonly reflect tectonic fabrics and structures within fractured target material. Despite the use of PICs in planetary geological interpretations, the formation mechanisms of these craters remain a topic of active study. The most widely studied PIC on Earth, Meteor Crater in Arizona, does not accurately reflect common PIC formation morphologies or mechanisms. This creates the need to study additional “ground truth” examples on Earth to determine how angular craters of different shapes may form. Studies regarding complex PIC formation are particularly scarce, with the leading hypothesis suggesting formation involves a combination of slumping and thrusting along pre-existing fractures. To help fill this knowledge gap, this study uses Oasis and B.P. Craters in Libya as terrestrial analogs for complex PICs and investigates whether this class of craters reflects pre-existing structural trends and tectonic fabrics. Both Oasis and B.P. Craters, located within the Kufra Basin of southeastern Libya, exhibit hexagonal shapes, even with their high degree of erosion. Despite both limited information about the subsurface of the Kufra Basin and the inability to conduct further field studies, these limitations create a unique terrestrial analog with investigation limited to remote sensing methods, similar to methods used in space exploration. Orientation data for complex crater features and local tectonic structures are analyzed to determine which tectonic fabrics influence crater morphology. Relationships between subsurface tectonic trends and complex crater structural features demonstrate how tectonic fabrics not only affect PICs of all sizes, but also how different fabrics control different formation stages.
Access
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