Southeastern Section - 60th Annual Meeting (23–25 March 2011)

Paper No. 16
Presentation Time: 1:30 PM-5:30 PM


GAY, N.K., Denr, North Carolina Geologial Survey, 1620 Mail Service Center, Raleigh, NC 27699-1620 and NICKERSON, J.G., Denr, North Carolina Geologial Survey, 1612 Mail Service Center, Raleigh, NC 27699-1612,

The sedimentary cover of the Lucama and Kenly East 1:24,000-scale quadrangles, located in the Raleigh 1:100,000-scale sheet was mapped as part of the STATEMAP Geologic Mapping Program. These quadrangles are in the Upper Coastal Plain of eastern North Carolina in parts of Johnston, Wilson, and Wayne Counties. Elevations range from about 300 feet in the northwest to about 90 feet on the eastern side of the quadrangles in the stream drainages. The Kenly Escarpment crosses the area at an elevation of about 170-feet in a northeast southwest orientation. The database collected for this mapping effort consists of twenty-five continuous cores, 58 power-auger drill holes, and 289 outcrops and field observations. Drill hole data reveals a relatively thin sedimentary package which rests on an irregular basement surface. This surface restricted the sediment distribution between pre-existing highs. Basement rocks include, but are not limited to, metasedimentary, metavolcanic, and at least two separate granitoid plutons. The metavolcanic Kenly Ridge along the western edge of the Lucama and Kenly East Quadrangles restricted the western limit of some of the earlier lithofacies. As sea level continued to rise, eventually this large feature was flooded. The oldest sedimentary unit identified in the mapped area is the Upper Pliocene Yorktown Formation consisting of two distinct lithofacies, the Rushmere and the Morgarts Beach Members. The post-Yorktown units comprise a very complex set of lithofacies that filled pre-existing paleo-drainages as sea level continued to rise. Continued sea level rise flooded drainage interfluves during the maximum sea-level event and sediments were deposited over the entire mapped area. Later as sea level began to fall, some pre-existing lithofacies were eroded out of the old paleo-drainages and new sedimentary packages were deposited in these drainages. Various lithofacies representing tidal flats, tidal channels, overwash deposits, fluvial channels, beach/shoreface complexes, barrier, and back barrier deposits, have been identified in the drill samples and in some outcrops.