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Marvin E. Davis

Publications and source records attributed to Marvin E. Davis.

10 recordsLinked to original sources
USGS1987

Geohydrologic framework of the coastal plain aquifers of South Carolina

The U.S. Geological Survey is conducting a series of investigations of aquifers throughout the United States as a part of the RASA (Regional Aquifer System Analysis) program. These investigations provide a comprehensive regional understanding of groundwater resources throughout the Nation. The Coastal Plain aquifers in South Carolina are being studied as a part of this program. An important part of a description of the groundwater resources is the development of a geohydrologic framework. Such a framework delineates the aquifers through which groundwater flows and the confining units which retard the flow of groundwater between aquifers. The Coastal Plain of South Carolina is underlain by a wedge of sediments that thickens from its inner margin, the Fall Line, to the coast and consists of sand, silt, clay, and limestone of Late Cretaceous to Holocene age. These sediments are underlain by pre-Cretaceous rocks consisting of consolidated sedimentary rocks of Triassic age and a complex of metamorphic and igneous rocks similar to those found near the surface in the Piedmont province of the State. The geohydrologic framework that divides the sediments of the South Carolina Coastal Plain into the Coastal Plain aquifer system is delineated by eleven geohydrologic sections and four maps showing the configuration of the top or base of individual aquifers. Although flow within the Coastal Plain aquifer system is three dimensional, simplifying the system by dividing it into a framework of discrete hydrologic units can aid significantly in understanding the hydrology of the system. This framework is the basis for the aquifers used in potentiometric mapping, transmissivity mapping, geochemical analysis, and groundwater flow modeling for the South Carolina RASA program. (Lantz-PTT)

South Carolina↗
USGS1986

Configuration and hydrology of the Pre-Cretaceous rocks underlying the southeastern Coastal Plain aquifer system

An investigation was conduced to define the configuration and hydrology of the rock surface upon which the sand aquifers and confining beds of the Southeastern Coastal Plain aquifer system were deposited. The base of the Southeastern Coastal Plain aquifer system consists of crystalline rocks, saprolite, Paleozoic rocks, Triassic sedimentary rocks (some of which are intruded by basalt), and Jurassic sedimentary rocks. The permeability of these rocks is extremely low and little exchange of water occurs upward to the overlying Cretaceous aquifers. Porosity values are in the range of 10% or less in some of the rocks, indicating little water is stored in them. The transmissivity values are extremely low, indicating very slow movement of water in these rocks. The small volume of water moving at a very slow rate has a long residence time and is usually mineralized to a greater degree than water in the more permeable overlying sediments. (Peters-PTT)

Water-Resources Investigations Report↗
USGS1975

Water availability and geology of Hale County, Alabama

Geologic units that underlie and crop out in Hale County include the Tuscaloosa Group, Eutaw Formation, and Selma Group of Late Cretaceous age, and terrace deposits and alluvium of Quaternary age. The Cretaceous units dip southwest about 35 feet per mile and strike northwest. They consist chiefly of deposits of sand, gravel, chalk, and clay. Potential sources of large supplies of ground water are major aquifers in the Coker, Gordo, and Eutaw Formations; expected yields are 1.5 mgd (million gallons per day per well). Aquifers in the Eutaw Formation are the shallowest source of ground water in most of the county. The average annual runoff originating in Hale County is about 17 inches or 0.82 mgd per square mile. The Black Warrior River, largest potential source of surface water in the county, has an average flow of 5,800 mgd at gaging station 2-4660 near Eutaw and a median annual 7-day low flow of 349 mgd. Elliotts, Fivemile, Big Brush, and Big Prairie Creeks also are potential sources of surface water. These creeks have average flows ranging from 35 to 210 mgd and median annual 7-day low flows in excess of 2 mgd at their lower reaches. Water from most streams in the county contains less than 10 mg/l (milligrams per liter) chloride and ranges from soft to hard. The mineral content of water from Big Brush Creek is affected by salty water from a flowing well. Ground water from the major aquifers contains less than 250 mg/l chloride, except in the extreme northwestern and west-central parts of the county, and ranges from soft to very hard. Water from the aquifers generally contains iron in excess of 0.3 mg/l except in the southern part of the county. Water use in Hale County in 1968 was about 3.9 mgd, most of which was ground water. Less than one percent of the potential water resources is being utilized.

Alabama↗
USGS1975

Surface-water availability, Tuscaloosa County, Alabama

The average annual runoff, about 1,270 mgd (million gallons per day), originating in Tuscaloosa County is equivalent to 20 inches or 0.95 mgd per square mile. The Black Warrior and Sipsey Rivers, the largest streams in the county, have average flows of 5,230 mgd and 580 mgd, respectively, where they leave the county, and median annual 7-day low flows in excess of 150 mgd and 35 mgd, respectively. North River, Big Sandy Creek, and Hurricane Creek have average flows in excess of 100 mgd and median annual 7-day low flows in excess of 2 mgd. Surface water generally contains less than 100 mg/l (milligrams per liter) dissolved solids, less than 10 mg/l chloride, and is soft to moderately hard. Streams having the higher hardness and the higher dissolved-solids content are in eastern Tuscaloosa County.

Open-File Report↗
USGS1975

Water availability and geology of Sumter County, Alabama

Geologic units that crop out in Sumter County include the Selma Group of Late Cretaceous age; the Midway and Wilcox Groups of Tertiary Age; and terrace deposits and alluvium of Quaternary age. The Tuscaloosa Group, consisting of the Coker and Gordo Formations, and Eutaw Formation of Late Cretaceous age underlie the entire county. The Cretaceous units dip southwestward about 45 feet per mile and strike northwestward. They consist chiefly of deposits of sand, gravel, chalk, and clay. Potential sources of large supplies of ground water are major aquifers in the Coker, Gordo, and Eutaw Formations; expected yields are 1.6 mgd (million gallons per day or more per well. The Naheola and Nanafalia formations, Tuscahome Sand, and terrace deposits and alluvium are expected to yield 10 to 50 gallons per minute per well.

Open-File Report↗