Month/Year of Graduation

5-2023

Degree Name

Bachelor of Science (B.S.)

Department

Geography and Geology

First Advisor

Dr. Harmon Maher Jr.

Abstract

Fracture nodes are useful in determining the connectivity of a fracture pattern which is important when considering hydrogeological and mechanical behavior of a rock. Four node types are used to describe the pattern, including isolated (I), perpendicular abutting (T), low-angle abutting (Y), and cross-cutting (X). Faults can affect a fracture pattern by creating a highly fractured zone in their vicinity. I investigate the Moab Tongue Member of the Entrada Formation at Castle Mesa in Moab, Utah to determine a) how the percentage of different node types changes with distance from the fault, b) any difference in node type proportions between the traversed and lower layer of the Moab Tongue Member sandstone, and c) what effect varying the sample size will have on the results. The node type percentages were calculated for multiple and overlapping rectangular polygons that aimed at capturing certain sample sizes and moved along a traverse. The resulting graphs show a noticeable increase in Y-nodes and decrease in X-node near the fault likely caused by fracture reactivation during faulting. Ternary diagram of the node types of the two layers shows a higher proportion of Y-nodes in the traverse layer which supports this theory.

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