Date of Graduation

Spring 2016

Document Type

Honors Research Project

Degree Name

Bachelor of Science

Major

Geology

Research Sponsor

Caleb Holyoke III

First Reader

James McManus

Second Reader

Ira Sasowsky

Abstract

The transition between significantly different materials is known to inhibit crack propagation, i.e. automobile glass, machinable ceramics and joints in different lithologies. In order to determine if a significant material transition, or a surface, such as a bedding plane, has a greater impact on inhibiting joint formation, I investigated discontinuous joints that formed during glacial unloading of the Sharon Sandstone, which is exposed at Gorge Metropark in Akron, Ohio. The Sharon Sandstone is a medium grained quartz arenite of Early Pennsylvanian age with significant cross-bedding, and contains many continuous (i.e. through-going), and discontinuous, joints in similar orientations. Stress fields created by unloading during glacial retreat following the last glacial maximum influenced joint orientations, spacing, and termination. 50% of the discontinuous joints observed terminated randomly within the outcrop, 20% terminated at free surfaces created by other joint sets, and 30% terminated at bedding planes. These results indicate that stress relaxation caused by joint formation exerts a larger control on joint termination than bedding planes or other surfaces in moderately homogenous rocks.

Included in

Geology Commons

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