b'A Petrologic and Petrographic Analysis of Calc-Silicate Layers from the Siluro-Devonian Mission Mountain Formation and the Precambrian Hothouse Formation, Murphy Belt, North CarolinaJessica L. ShoresSponsor: Dr. GroszosCalc-silicate rich layers occur in metasedimentary rocks of the Murphy Belt in North Carolina and Georgia. Calc-silicate layers contain an abundance of calcium-bearing silicate minerals and are usually light-colored, but darker layers have been described. Early workers incorrectly called these calc-silicate layers pseudodiorite. Both the Mission Mountain Formation of the Siluro-Devonian Mineral Bluff Group and the Hothouse Formation of the Precambrian Great Smoky Group contain calc-silicate layers. The Great Smoky Group is related to Rodinian rifting, whereas the Mission Mountain Formation is successor basin related. The presence of calc-silicate layers suggests these rocks were originally marls, with a locally derived carbonate sedimentary component prior to metamorphism. Preliminary analysis of a calc-silicate sample from the Mission Mountain Formation revealed the presence of quartz, garnet, biotite, chlorite, epidote, diopside, and fluorite (?). The current study is a petrologic and petrographic analysis of several calc-silicate layers from two distinct outcrops of the Mission Mountain Formation in Murphy, North Carolina. One float sample was collected from the Hothouse Formation near Hanging Dog Creek, North Carolina for comparison. These samples will undergo further analysis, including a petrographic point count.Calc-silicate rocks provide important information regarding the protolith and depositional environment.Analysis of Fractures in the Oligocene Suwannee Limestone Exposed along the Withlacoochee River South of Madison Blue Spring, FloridaJoshua C. GraysonSponsor: Dr. GroszosThe Withlacoochee River is in north Florida is a major tributary to the Suwanee River. The Withlacoochee has many karst-topography related exposures of limestone that show numerous fractures. The fractures provide valuable information to geologists studying the Floridian aquafer as these fractures may allow ground contaminates to leech into the aquafer. The outcrops were accessed by canoe traverse along a six mile stretch on the Withlacoochee starting at Blue Hole Park in OBrien, Florida and ending six miles downstream towards the Suwanee River. A total of 60 fractures were measured using a Brunton compass to determine the strike of the fractures. The fractures are vertical, so dip measurements were not taken. The outcrop locations were recorded on a handheld GPS. Several measurements were taken at each outcrop. The resulting strike measurements were plotted into a stereonet to be further analyzed and reveal major, secondary, and minor trends. After analyzing the data, the major trend is approximately N 40 W, the secondary trend is approximately N 35 E, and a minor trend of N 70 E. The results from this study will be combined and compared with other similar studies to characterize the regional fracture trends in the area.48'