U.S. Geological Survey (USGS) geologic discipline (GD) scientists from Woods Hole, MA, Woodshole and their collaborators continued the mapping the regional sedimentary framework of the inner shelf of northern North Carolina to understand recent coastal processes, including erosion and the impacts of shoreline change.
There were 6 test holes drilled in the outer banks region from Nags Head to Cape Hattaras Island from April 6 to April 17, 2003. The rotosonic-drilling team recovered almost 900 ft of sediment cores from six sites, including one mainland site, and measured the salinity of 130 pore-water samples. Bill Hoffman of the North Carolina Geological Survey collected the core samples and they are analyzing the stratigraphy. The WRD office of Raleigh, North Carolina geophysically logged the testholes. Beth Wrege and other USGS scientists from offices in North Carolina and Reston, VA, conducted gamma logging of each hole and installed monitoring wells at several sites.
Stratigraphic section collected continuous core using a vibrasonic core rig. USGS-Woodshole had John Bratton on site collecting pore water and running salinity determinations of the aquifer water for each five foot depth interval efforts to understand the evolution and modern dynamics of the State's extensive barrier-island system, including its hydrogeology. USGS WRD hydrologist Beth Wrege designed and installed 3 monitoring wells in three of the test holes. These were OBX 10, OBX 13, and MLD 01.
Other participants in the drilling program included Bill Hoffman and Bob Brooks (North Carolina Geological Survey); Reide Corbett, Lance Tully, and Irene Abbene (East Carolina University); and an excellent drilling crew from Boart Longyear. Additional chemical analyses are being performed on pore-water samples at East Carolina University.
This work is being done in cooperation with the NPS. The results of these groundwater monitoring sites will supplement existing knowledge of salt water intrusion. Water levels and salinity water is being monitored in two of the three wells. The USGS WRD is continuing to collect data on the freshwater aquifers in the outer banks region.