ATLANTIC COASTAL PLAIN HYDROSTRATIGRAPHY FOR WATER SUPPLY
During March and April 2004, USGS scientists used a wireline continuous-core drill rig to complete a deep (1,094.5-foot) stratigraphic corehole to basement (Triassic basin) at the Hope Plantation in Bertie County, North Carolina. This study area in northeast North Carolina is of special interest because it lies slightly southeast of an anomalous pattern of rapid eastward drop-off in the geologic layers of the Coastal Plain. The possibility of faults, which would significantly complicate the geologic and hydrologic interpretation of the subsurface geology, is being investigated.
A suite of borehole geophysical surveys was obtained, in the open borehole, and a ground-water monitoring piezometer also was installed at the Hope Plantation site. The core samples and supportive data were used to determine the thickness of the aquifers and confining units at this site. Scientists collected geologic and paleontologic information sufficient to define the stratigraphic units underlying the site. The joint hydrologic and geologic analyses provide a hydrostratigraphic anchor point and a detailed snapshot of the regional aquifers and confining units. Increased understanding of the geologic controls in the Coastal Plain will ultimately help assess the effects of existing and future withdrawals from the system.