A Mineralogical Analysis of Eastern North Carolina (2009)

Undergraduates: Miquela Ingalls, Fall 2008 Earth Materials Class none none

Faculty Advisor: Drew Coleman
Department: Geology

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The members of the Fall 2007 Earth Materials class conducted a mineralogical analysis of samples collected at several locations in Eastern North Carolina. Our objectives were to gain field experience and to determine the mineralogical makeup of various rocks and sediments with the aim of describing the geologic history of North Carolina. Locations that were investigated include Cliffs of Neuse State Park, Falls Lake, Durham, the Neuse River and Carolina Beach. At each location, field observations were recorded and samples were collected. Sample analysis was undertaken using the department’s scanning electron microscope. The whole rock samples were readied for the SEM using a diamond-blade rock saw, and the sediments were prepared as grain mounts. The SEM methods utilized were backscatter imaging, cathodoluminescence, and x-ray mapping. From this data we constructed models of formation for each sample. Our findings are consistent with North Carolina’s history of regional metamorphism, and point to the generally accepted formational model of North Carolina’s eastern piedmont as an island arc that collided with North America approximately 450 million years ago. Basic geological principles of erosion and sediment transfer were identified as the mechanisms by which the coastal plain and beaches of the state were formed.