Geophysical well-log data base for the Gulf Coast aquifer systems, south-central United States

Abstract

As part of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program, the Gulf Coast RASA was begun to investigate groundwater flow systems in the Coastal Plain of the south-central United States. Three regional aquifer systems are identified in the area. The Mississippi embayment aquifer system and the Texas coastal uplands aquifer system are composed predominantly of Eocene sediments; the coastal lowlands aquifer system is composed predominantly of Oligocene and younger sediments. Automated data-processing techniques were chosen to facilitate a study of this magnitude. A computer database of information derived from almost 1,000 geophysical well logs was constructed to support the delineation of the geohydrologic framework of the study area and the simulation of groundwater flow. The database contains entries pertaining primarily to physical characteristics of the hydrologic units.

Summary of hydrology of the regional aquifer systems, Gulf Coastal Plain, south-central United States

“…Progress on the study was reported by Grubb (1985, 1986b, 1987, 1992); Wilson and Hosman (1988) described a geophysical well-log data base; Weiss and Williamson (1985) presented a method for vertically subdividing thick sedimentary units; and maps, sections, and diagrams of the geohydrologic framework were constructed by Hosman (1982Hosman ( , 1988; Arthur and Taylor (1986); Mesko (1988Mesko ( , 1990; Parks and Carmichael (1989, 1990b, 1990c; Taylor and Arthur (1989);. Potentiometric surface maps were prepared for several aquifers, some for the first time, by Ackerman (1987aAckerman ( , 1987bAckerman ( , 1989b; Boswell and Arthur (1988); Garza and others (1987); Martin and Whiteman (1985a, 1985b; Martin and others andCarmichael (1990a, 1990b).…”

Potentiometric surface of the Mississippi River Valley alluvial aquifer, spring 2016

“…• The potentiometric surface raster, which was output from the interpolation process, was compared to a raster of the aquifer base (Saucier, 1994;Wilson and Hosman, 1987;Hart and others, 2008; James Hoffmann, Mississippi Department of Environmental Quality, written commun., February 2018; Joseph Richards, U.S. Geological Survey, written commun., March 2018; Wacaster and others, 2018) to identify where the input potentiometric surface raster was below the aquifer-base raster.…”

Hydrogeological modeling of submarine groundwater discharge on the continental shelf of Louisiana

“…The hydraulic conductivity values for Permeable Zones C, D, and E are somewhat lower than Prudic's values. However, the majority of well tests on which Prudic [1991] based his analysis for Permeable Zones C-E were carried out in more permeable outcrop regions [Wilson and Hosman, 1988]. In calibrating their groundwater flow model of the Coastal Lowlands Aquifer System, Williamson and Grubb [2001] determined that the hydraulic conductivity of Zones C -E were much lower in southern Louisiana than in the north.…”