Datasets used to represent the ten subunits of the Texas Coastal Uplands and Mississippi Embayment aquifer system, Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas (ver. 2.0, March 2026)

Note that this data release has been modified from its original version. This data release was originally published as a geodatabase in 2015, and is still available, but the data are considered outdated. In 2025, the following changes were made to the data release:
  1. All of the data files were extracted from the original geodatabase as either Tiff or shapefiles. This was completed because the geodatabase was outdated, some of the image files did not appear as intended, and the new formats are more accessible for the user. 
  
  2. Confining subunit data were added to the data release from U.S. Geological Survey Professional Paper 1416-B (USGS PP 1416-B). Confining subunit extents, contour lines, images, and rasters were all added as the original data release only contained aquifer subunit data. 
  
  3. The aquifer subunit altitude rasters were remade. It was found that the altitude rasters in the original data release contained some inconsistencies. Some of the rasters were not clipped to their associated extent. The source maps for the rasters dictate areas of "outcrop or subcrop". In the original version of this data release, these areas were treated as land surface which is not accurate. The new version of these rasters correct these errors and account for the additional confining unit data. The new rasters have a cell size of 1000 meters, are snapped to the National Hydrogeologic Grid (NHG; Clark and others, 2018), and have altitude values in meters above North American Vertical Datum of 1988 (NAVD88). 
  
  4. The extent files were updated with confining unit data, and ancillary metadata from the extent and contour line shapefiles were removed. 
  
  5. The title of the data release was updated. The original title read, "Geodatabase of the datasets used to represent the six subunits of the Texas Coastal Uplands and Mississippi Embayment aquifer system, Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas". This product is no longer a geodatabase and now contains 10 subunits. The new title was composed to reflect these changes. 
  
  6. Two versions of the subunit altitude rasters are included in this data release. The first version of the rasters was reconciled and corrected to make sure that the subunits did not overlap. There were many areas where underling rasters were above overlying rasters due to the inexact nature of generating rasters from hand drawn maps which were created from well log data. Reconciling the rasters caused the thickness of some subunits to become zero where they overlapped. See attribute accuracy report and process E below for more detail on this process. The second version of the rasters do not include this reconciliation step, and therefore, do not create thickness values of “0” for any of the subunits. Both versions are included to provide the user the option to choose which version might be better for them depending on their needs. The folder containing the reconciled rasters is named “rasters”, and the folder containing the unreconciled rasters is named “rasters_unrec”. The names of the unreconciled rasters end in "_unrec". 
  
The Texas Coastal Uplands and Mississippi Embayment aquifer system has six aquifer subunits and four confining subunits. The aquifer units are numbered 1 to 6 with the prefix of "A", and the confining subunits are numbered 1 to 4 with the prefix "CU".
In order from the most surficial to the deepest: 
 
CU1: Vicksburg-Jackson confining unit
A1: Upper Claiborne aquifer
CU2: Middle Claiborne confining unit
A2: Middle Claiborne aquifer
CU3: Lower Claiborne confining unit
A3: Lower Claiborne- Upper Wilcox aquifer
A4: Middle Wilcox aquifer 
A5: Lower Wilcox aquifer
CU4: Midway confining unit
A6: McNairy-Nacatoch aquifer
  
This data release includes spatial datasets that represent the Texas Coastal Uplands and Mississippi Embayment aquifer system in the States of Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas. Included are: (1) polygon extents; datasets that represent the aquifer system extent, the entire extent subdivided into subunits, and outcrop extents, (2) altitude, and thickness contours used to generate altitude rasters, (3) raster datasets of the top and bottom altitude of each aquifer and confining unit, (4) georeferenced images of the figures that were digitized to create the extent files and the altitude and thickness contours. The images and digitized contours are supplied for reference. 
 
This data release includes the following spatial datasets:
 
1. Aquifer system extent and outcrop datasets
 
a. ds19TXCLUP_20MSEMBM_erev.shp: Areal extent of the entire Texas Coastal Uplands-Mississippi Embayment aquifer system; a combined extent from USGS PP 1416-B plates 10 through 19
 
b. ds19TXCLUP_20MSEMBM_erev_w_SubUnits.shp; extent of the entire Texas Coastal Uplands-Mississippi Embayment aquifer system with the subunit boundaries delineated; from USGS PP 1416-B plates 10 through 19
 
c. ds19TXCLUP_20MSEMBM_outcrop_areas.shp; extents of areas within the Texas Coastal Uplands-Mississippi Embayment aquifer system that are at the land surface; from USGS PP 1416-B plates 10 through 19
 
 
2. Top altitude and thickness contour line datasets. The altitude values are in feet above the National Geodetic Vertical Datum of 1929 (NGVD29).
 
Aquifer subunits:
a. ds19TXCLUP_20MSEMBM_A1_thk_PP1416B_p11_fb.shp; contours of thickness of subunit A1 (Upper Claiborne aquifer), from USGS PP 1416-B, plate 11, figure b; titled "Thickness of the Upper Claiborne aquifer"
 
b. ds19TXCLUP_20MSEMBM_A1_top_PP1416B_p11_fa.shp: contours of altitude of top of subunit A1 (Upper Claiborne aquifer), from USGS PP 1416-B, plate 11 figure a; titled "Altitude and configuration of the top of the Upper Claiborne aquifer"
 
c. ds19TXCLUP_20MSEMBM_A2_thk_PP1416B_p13_fb.shp; contours of thickness of subunit A2 (Middle Claiborne aquifer), from USGS PP 1416-B, plate 13, figure b; titled "Thickness of the Middle Claiborne aquifer"
 
d.  ds19TXCLUP_20MSEMBM_A2_top_PP1416B_p13_fa.shp: contours of altitude of top of subunit A2 (Middle Claiborne aquifer), from USGS PP 1416-B, plate 13, figure a; titled "Altitude and configuration of the Middle Claiborne aquifer"
 
e. ds19TXCLUP_20MSEMBM_A3_thk_PP1416B_p15_fb.shp: contours of thickness of subunit A (Lower Claiborne-Upper Wilcox aquifer), from USGS PP 1416-B, plate 15, figure b; titled "Thickness of the Lower Claiborne-Upper Wilcox aquifer"
 
f. ds19TXCLUP_20MSEMBM_A3_top_PP1416B_p15_fa.shp: contours of altitude of top of subunit A3 (Lower Claiborne-Upper Wilcox aquifer), from USGS PP 1416-B, plate 15, figure a; titled "Altitude and configuration of the top of the Lower Claiborne-Upper Wilcox aquifer"
 
g. ds19TXCLUP_20MSEMBM_A4_thk_PP1416B_p16_fb.shp: contours of thickness of subunit A4 (Middle Wilcox aquifer), from USGS PP 1416-B, plate 16, figure b; titled "Thickness of the Middle Wilcox aquifer"
 
h. ds19TXCLUP_20MSEMBM_A4_top_PP1416B_p16_fa.shp: contours of altitude of top of subunit A4 (Middle Wilcox aquifer), from USGS PP 1416-B, plate 16 figure a; titled "Altitude and configuration of the top of the Middle Wilcox aquifer"
 
i. ds19TXCLUP_20MSEMBM_A5_thk_PP1416B_p17_fb.shp: contours of thickness of subunit A5 (Lower Wilcox aquifer), from USGS PP 1416-B, plate 17, figure b; titled "Thickness of the Lower Wilcox aquifer"
 
j. ds19TXCLUP_20MSEMBM_A5_top_PP1416B_p17_fa.shp: contours of altitude of top of subunit A5 (Lower Wilcox aquifer), from USGS PP 1416-B, plate 17 figure a; titled "Altitude and configuration of the top of the Lower Wilcox aquifer"
 
k. ds19TXCLUP_20MSEMBM_A6_thk_PP1416B_p19_fb.shp: contours of thickness of subunit A6 (McNary-Nacatoch aquifer), from USGS PP 1416-B, plate 19, figure b; titled "Thickness of the McNary-Nacatoch aquifer"
 
l. ds19TXCLUP_20MSEMBM_A6_top_PP1416B_p19_fa.shp: contours of altitude of top of subunit A6 (McNary-Nacatoch aquifer), from USGS PP 1416-B, plate 19 figure a; titled "Altitude and configuration of the top of the McNary-Nacatoch aquifer"
 
 
Confining subunits: 
 
m. ds19TXCLUP_20MSEMBM_CU1_thk_PP1416B_p10_fb.shp: contours of thickness of subunit CU1 (Vicksburg-Jackson confining unit), from USGS PP 1416-B, plate 10, figure b; titled "Thickness of the Vicksburg-Jackson confining unit"
 
n. ds19TXCLUP_20MSEMBM_CU1_top_PP1416B_p10_fa.shp: contours of altitude of top of subunit CU1 (Vicksburg-Jackson confining unit), from USGS PP 1416-B, plate 10 figure a; titled "Altitude and configuration of the top of the Vicksburg-Jackson confining unit"
 
o. ds19TXCLUP_20MSEMBM_CU2_thk_PP1416B_p12_fb.shp: contours of thickness of subunit CU2 (Middle Claiborne confining unit), from USGS PP 1416-B, plate 12, figure b; titled "Thickness of the Middle Claiborne confining unit"
 
p. ds19TXCLUP_20MSEMBM_CU2_top_PP1416B_p12_fa.shp: contours of altitude of top of subunit CU2 (Middle Claiborne confining unit), from USGS PP 1416-B, plate 12 figure a; titled "Altitude and configuration of the top of the Middle Claiborne confining unit"
 
q. ds19TXCLUP_20MSEMBM_CU3_thk_PP1416B_p14_fb.shp: contours of thickness of subunit CU3 (Lower Claiborne confining unit), from USGS PP 1416-B, plate 14, figure b; titled "Thickness of the Lower Claiborne confining unit"
 
r. ds19TXCLUP_20MSEMBM_CU3_top_PP1416B_p14_fa.shp: contours of altitude of top of subunit CU3 (Lower Claiborne confining unit), from USGS PP 1416-B, plate 14 figure a; titled "Altitude and configuration of the top of the Lower Claiborne confining unit"
 
s. ds19TXCLUP_20MSEMBM_CU4_thk_PP1416B_p18_fb.shp: contours of thickness of subunit CU4 (Midway confining unit), from USGS PP 1416-B, plate 18, figure b; titled "Thickness of the Midway confining unit"
 
t. ds19TXCLUP_20MSEMBM_CU4_top_PP1416B_p18_fa.shp: contours of altitude of top of subunit CU4 (Midway confining unit), from USGS PP 1416-B, plate 18 figure a; titled "Altitude and configuration of the top of the Midway confining unit"
 
 
3.  Altitude top and thickness surface raster datasets of each aquifer and confining subunit. The altitude values are in meters above NAVD88. Two versions of these rasters are included in this data release, those that have been reconciled to not have any overlap between subunits, and an unreconciled version. The unreconciled version's file names end in "_unrec". An example of this is for raster "r19TXCLUP_20MSEMBM_A1_top.tif', the unreconciled version is named "r19TXCLUP_20MSEMBM_A1_top_unrec.tif". The "_unrec" files are not listed below.   
 
a. r19TXCLUP_20MSEMBM_A1_top.tif: Altitude of top layer of subunit A1 (Upper Claiborne aquifer)
 
b. r19TXCLUP_20MSEMBM_A1_bot.tif: Altitude of bottom layer of subunit A1 (Upper Claiborne aquifer)
 
c. r19TXCLUP_20MSEMBM_A2_top.tif: Altitude of top layer of subunit A2 (Middle Claiborne aquifer)
 
d. r19TXCLUP_20MSEMBM_A2_bot.tif: Altitude of bottom layer of subunit A2 (Middle Claiborne aquifer)
 
e. r19TXCLUP_20MSEMBM_A3_top.tif: Altitude of top layer of subunit A3 (Lower Claiborne-Upper Wilcox  aquifer)
 
f. r19TXCLUP_20MSEMBM_A3_bot.tif: Altitude of bottom layer of subunit A3 (Lower Claiborne-Upper Wilcox  aquifer)
 
g. r19TXCLUP_20MSEMBM_A4_top.tif: Altitude of top layer of subunit A4 (Middle Wilcox aquifer)
 
h. r19TXCLUP_20MSEMBM_A4_bot.tif: Altitude of bottom layer of subunit A4 (Middle Wilcox aquifer)
 
i. r19TXCLUP_20MSEMBM_A5_top.tif: Altitude of top layer of subunit A5 (Lower Wilcox aquifer)
 
j. r19TXCLUP_20MSEMBM_A5_bot.tif: Altitude of bottom layer of subunit A5 (Lower Wilcox aquifer)
 
k. r19TXCLUP_20MSEMBM_A6_top.tif: Altitude of top layer of subunit A6 (McNairy-Nacatoch aquifer)
 
l. r19TXCLUP_20MSEMBM_A6_bot.tif: Altitude of bottom layer of subunit A6 (McNairy-Nacatoch aquifer)
 
m. r19TXCLUP_20MSEMBM_CU1_top.tif: Altitude of top layer of subunit CU1 (Vicksburg-Jackson confining unit)
 
n. r19TXCLUP_20MSEMBM_CU1_bot.tif: Altitude of bottom layer of subunit CU1 (Vicksburg-Jackson confining unit)
 
o. r19TXCLUP_20MSEMBM_CU2_top.tif: Altitude of top layer of subunit CU2 (Middle Claiborne confining unit)
 
p. r19TXCLUP_20MSEMBM_CU2_bot.tif: Altitude of bottom layer of subunit CU2 (Middle Claiborne confining unit)
 
q. r19TXCLUP_20MSEMBM_CU3_top.tif: Altitude of top layer of subunit CU3 (Lower Claiborne confining unit)
 
r. r19TXCLUP_20MSEMBM_CU3_bot.tif: Altitude of bottom layer of subunit CU3 (Lower Claiborne confining unit)
 
s. r19TXCLUP_20MSEMBM_CU4_top.tif: Altitude of top layer of subunit CU4 (Midway confining unit)
 
t. r19TXCLUP_20MSEMBM_CU4_bot.tif: Altitude of bottom layer of subunit CU4 (Midway confining unit)
 
 
4. Georeferenced image files of extent, top altitude contour line, and thickness contour line data of each subunit.
 
a. gri19TXCLUP_20MSEMBM_A1_top_PP1416B_p11_fa.tif: image of plate 11, figure a, from USGS PP 1416-B
 
b. gri19TXCLUP_20MSEMBM_A1_thk_PP1416B_p11_fb.tif: image of plate 11, figure b, from USGS PP 1416-B
 
c. gri19TXCLUP_20MSEMBM_A2_top_PP1416B_p13_fa.tif: image of plate 13, figure a, from USGS PP 1416-B
 
d. gri19TXCLUP_20MSEMBM_A2_thk_PP1416B_p13_fb.tif: image of plate 13, figure b, from USGS PP 1416-B
 
e. gri19TXCLUP_20MSEMBM_A3_top_PP1416B_p15_fa.tif: image of plate 15, figure a, from USGS PP 1416-B
 
f. gri19TXCLUP_20MSEMBM_A3_thk_PP1416B_p15_fb.tif: image of plate 15, figure b, from USGS PP 1416-B
 
g. gri19TXCLUP_20MSEMBM_A4_top_PP1416B_p16_fa.tif: image of plate 16, figure a, from USGS PP 1416-B
 
h. gri19TXCLUP_20MSEMBM_A4_thk_PP1416B_p16_fb.tif: image of plate 16, figure b, from USGS PP 1416-B
 
i. gri19TXCLUP_20MSEMBM_A5_top_PP1416B_p17_fa.tif: image of plate 17, figure a, from USGS PP 1416-B
 
j. gri19TXCLUP_20MSEMBM_A5_thk_PP1416B_p17_fb.tif: image of plate 17, figure b, from USGS PP 1416-B
 
k. gri19TXCLUP_20MSEMBM_A6_top_PP1416B_p19_fa.tif: image of plate 19, figure a, from USGS PP 1416-B
 
l. gri19TXCLUP_20MSEMBM_A6_thk_PP1416B_p19_fb.tif: image of plate 19, figure b, from USGS PP 1416-B
 
m. gri19TXCLUP_20MSEMBM_CU1_thk_PP1416B_p10_fb.tif: image of plate 10, figure b, from USGS PP 1416-B
 
n. gri19TXCLUP_20MSEMBM_CU1_top_PP1416B_p10_fa.tif: image of plate 10, figure a, from USGS PP 1416-B
 
o. gri19TXCLUP_20MSEMBM_CU2_thk_PP1416B_p12_fb.tif: image of plate 12, figure b, from USGS PP 1416-B
 
p. gri19TXCLUP_20MSEMBM_CU2_top_PP1416B_p12_fa.tif: image of plate 12, figure a, from USGS PP 1416-B
 
q. gri19TXCLUP_20MSEMBM_CU3_thk_PP1416B_p14_fb.tif: image of plate 14, figure b, from USGS PP 1416-B
 
r. gri19TXCLUP_20MSEMBM_CU3_top_PP1416B_p14_fa.tif: image of plate 14, figure a, from USGS PP 1416-B
 
s. gri19TXCLUP_20MSEMBM_CU4_thk_PP1416B_p18_fb.tif: image of plate 18, figure b, from USGS PP 1416-B
 
t. gri19TXCLUP_20MSEMBM_CU4_top_PP1416B_p18_fa.tif: image of plate 18, figure a, from USGS PP 1416-B