Aquifers in Cretaceous rocks of the central Coastal Plain of North Carolina
Links
- Document: Report (pdf)
- Plates:
- Download citation as: RIS | Dublin Core
Abstract
Aquifers in rocks of Cretaceous age are the major source of groundwater for public supplies in the central Coastal Plain. These aquifers consist of sand, gravel, and limestone beds of the Peedee, Black Creek, and the upper and lower Cape Fear aquifers, each separated by a confining unit composed of clay and silt beds. The aquifers and confining units (1) rest upon crystalline basement rocks; (2) dip and thicken to the east-southeast; and (3) are overlain by younger aquifers and confining units in deposits of Quaternary and Tertiary age. The top of the uppermost aquifer, the Peedee, ranges from 122 ft above to 595 ft below sea level. The maximum thickness of all aquifers and confining units in Cretaceous rocks is more than 1,600 ft.
Aquifers and confining units were defined and correlated for this report using 125 geophysical logs and accompanying drillers' logs, water level data, and water quality information regarding chloride concentrations in water. This analysis allowed the construction of seven hydrogeologic cross sections that depict the continuity of all the aquifers and confining units. These cross sections also show water levels and chloride concentrations in water from various test intervals and describe where chloride concentration in water exceeds 250 mg/L within each aquifer.
Detailed maps of each Cretaceous aquifer show altitude of its top, thickness, areas of selected sand percentages, transition zones from fresh to saltwater, and the thickness of the confining unit. Hydrogeologic data for all aquifers and confining units are presented in tabular form.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Aquifers in Cretaceous rocks of the central Coastal Plain of North Carolina |
| Series title | Water-Resources Investigations Report |
| Series number | 87-4178 |
| DOI | 10.3133/wri874178 |
| Year Published | 1989 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | South Atlantic Water Science Center |
| Description | Report: v, 71 p.; 20 Plates: 34.00 x 24.96 inches or smaller |
| Country | United States |
| State | North Carolina |
| Other Geospatial | Coastal Plain |
| Google Analytic Metrics | Metrics page |