Tuesday, May 12, 2015

URSP Student Carlin Green Conducts 3-D Strain Analysis in the Blue Ridge Anticlinorium

My research project is centered on determining three-dimensional strain geometry in the Antietam formation, a sandstone unit exposed on the East and West limbs of the Blue Ridge Anticlinorium.  This is an area in which many of our field trips take place in the Geology department, and where I grew up, so it was natural for me to take an interest in the area.  It was my desire to complete undergraduate research in order to bolster my prospects for graduate school and to gain experience doing field work and lab research.  There have been many stages in the development of this project.  My mentor, John Singleton, and I made several trips to the field to collect rock samples which we then cut and shipped across the country to be made into thin sections suitable for study under a petrographic microscope.  From there I spent a large portion of time collecting data from thousands of deformed quartz grains in order to characterize what is known as the Strain Ellipse, the geometry of which allows us to understand the deformational history in this area.  In a few weeks, we will travel to Washington & Lee University to perform Electron Backscatter Diffraction analysis on several samples, which will yield more information about the geometry and orientation of crystallographic axes.  One thing I discovered this week is that in one particular area, which we intend to map, you can walk from a low-strain to a high-strain environment in a very short distance.  Although it is not yet clear, these strain ratios may exceed recorded strain data for this area.  This is quite interesting and requires close examination.