thumbnail

Application of geophysical methods to the delineation of paleochannels and missing confining units above the Castle Hayne Aquifer at US Marine Corps Air Station, Cherry Point, North Carolina

Water-Resources Investigations Report 95-4252

By:
, , and

Links

Abstract

The U.S. Marine Corps Air Station, Cherry Point, North Carolina, is underlain by four freshwater-bearing aquifers--the surficial, Yorktown, and upper and lower Castle Hayne. The upper and lower Castle Hayne aquifers serve as the principal supply of freshwater for the Air Station. The potential for movement of contaminated water from the surficial aquifer downward to the water-supply aquifer is greatest in areas where clay confining units are missing. Missing confining units may indicate the presence of paleochannels filled with permeable material. Seismic-reflection techniques were successful in delinea- ting paleochannels of Quaternary and Tertiary age within unconsoli- dated sediments less than 180 feet deep at several locations. Continuous single-channel marine seismic-reflection profiling in the Neuse River was effective in delineating a large paleochannel complex consisting of at least two superimposed paleochannels within hydrogeologic units overlying the upper Castle Hayne aquifer. The complex was found immediately north of the Air Station and is thought to continue south beneath the Air Station. Shallow high-resolution land seismic-reflection techniques were used at the Air Station to delineate structures and correlate strati- graphy between the limestone of the upper Castle Hayne aquifer and the Yorktown confining unit. Three different land seismic-reflection techniques proved effective for the horizontal extrapolation of geo- logic features and identification of paleochannels at several locations. The northeastern margin of a large paleochannel was identified beneath the southern part of the Air Station. This feature strikes northwest to southeast and cuts through the Yorktown and upper Castle Hayne aquifer confining units.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Application of geophysical methods to the delineation of paleochannels and missing confining units above the Castle Hayne Aquifer at US Marine Corps Air Station, Cherry Point, North Carolina
Series title:
Water-Resources Investigations Report
Series number:
95-4252
Edition:
-
Year Published:
1995
Language:
ENGLISH
Publisher:
U.S. Geological Survey ; Earth Science Information Center, Open-File Reports Section [distributor],
Description:
v, 106 p. :ill., maps ;28 cm.