Mentor: Dr. Arlo Weil
The mechanics behind the formation of mountain belts is a central aspect of structural geology. As most mountain belts display some curvature in their plan view, the development of curved mountain belts is of particular interest. Curved mountain belts are classified into three different groups based on their kinematic history, or the means and timing by which they acquire their curvature. Primary Arcs are curved during the initial phase of formation, Oroclines are belts that acquire their curvature during a secondary deformational phase, and Progressive Oroclines are mountain belts that acquire their curvature synchronous with deformation. Thus, answering the question of when curvature in a mountain belt occurred is essential to understanding their formation. This summer’s project will focus on the Wyoming Salient, a highly curved portion of the Rocky Mountains between Jackson Hole , Wyoming and Salt Lake City , Utah .
Paleomagnetism, the study of the Earth’s ancient magnetic field as recorded in the rock record, can be used to quantify rotations that a mountain belt has undergone. In conjunction with strain data and structural data, paleomagnetically derived rotations can be used to produce a three dimensional kinematic model that will allow for the complete restoration of the belt. Paleomagnetic data, field observations, and structural measurements will be collected this summer throughout the Wyoming Salient. Drilling and orienting will be concentrated along three swaths (north, central, and south). Data samples will be brought to Bryn Mawr College and prepared for lab analysis. Samples will then be analyzed in the soon-to-be paleomagnetic lab, using a spinner-type magnetometer.