MERAS readme file

The text files contained in this directory are the digital hydrogeologic 
surfaces developed for the Mississippi Embayment Regional Aquifer Study 
(MERAS) ground-water flow model by the United States Geological Survey 
(USGS) Arkansas Water Science Center (ARWSC). 

The accompanying Scientific Investigations Report 2008-5098, Digital 
Surfaces and Thicknesses of Selected Hydrogeologic Units within the 
Mississippi Embayment Regional Aquifer Study (MERAS), can be found at:
http://pubs.er.usgs.gov/usgspubs/sir/sir20085098. 

Each digital hydrogeologic surface is in Grid ASCII format and the projection 
is USA Contiguous Albers Equal Area Conic. The hydrogeologic surfaces were 
exported from ArcMap© Version 9.2 containing Service Pack 4. The Grid ASCII 
file names and the hydrogeologic units they represent are listed below:

vkbg_surf.txt - Vicksburg-Jackson Group;
ucaq_surf.txt - upper Claiborne aquifer;
mccu_surf.txt - middle Claiborne confining unit;
mcaq_surf.txt - middle Claiborne aquifer;
lccu_surf.txt - lower Claiborne confining unit;
lcaq_surf.txt - lower Claiborne aquifer;
uwaq_surf.txt - upper Wilcox aquifer;
lwaq_surf.txt - lower Wilcox aquifer;
mdwy_surf.txt - Midway confining unit.

The use of firm, trade, and brand names is for identification purposes only
and does not constitute endorsement by the U.S. Geological Survey.

For additional information write to:
Director
U.S. Geological Survey Arkansas Water Science Center
401 Hardin Rd
Little Rock, AR, 72211