Eagle Ford Formation (TXKef;0)

State	Texas
Name	Eagle Ford Formation
Geologic age	Late Cretaceous
Lithologic constituents	Major Sedimentary > Clastic > Siltstone (Bed) Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed) Incidental Sedimentary > Carbonate > Limestone (Bed)
Comments	In North, central, and south Texas including Quaternary for all of west Texas- Shale, siltstone, and limestone; upper part limest. and shale, ls lt-yellowish-brown, flaggy; lower part, siltst. and v. fine-grained sandst., lt-yellow to gray, laminated flaggy, some limestone, silty, med-brown, laminated, thickness 75-200 ft, thins NEward. In East Texas and Gulf Coast to Rio Grande- Shale and limestone. Upper part-- shale, compact, silty, contains fossil fish teeth and bones, 10 ft or more thick; middle part-- silty limest grading to calcar siltst, med gray weathers pale yellowish-brown, flaggy; lower part--shale, calcareous, dk gray, 7-50 ft thick. Thickness of Eagle Ford Formation 25-65 ft. In Texarkana Sheet (1966) thickness 60 ft feathers out east. In Sherman Sheet (1967) (NE Texas) shale, selenitic, bituminous, calcar concretions and septaria, thin platy beds of sandst. and sandy ls. in middle and upper part, med to dk gray; marine megafossils; thickness 300-400 ft.
References	Bureau of Economic Geology, 1977, Del Rio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1966, Texarkana Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1967, Sherman Sheet, Geologic Atlas of Texas: University of Texas at Austin, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000.
NGMDB product	NGMDB product page for 68390
Counties	Bell - Collin - Comal - Dallas - Denton - Edwards - Ellis - Fannin - Grayson - Hays - Hill - Johnson - Kinney - Lamar - McLennan - Medina - Red River - Tarrant - Uvalde - Val Verde - Williamson

State

Texas

Name

Eagle Ford Formation

Geologic age

Late Cretaceous

Lithologic constituents

Major

Sedimentary > Clastic > Siltstone (Bed)

Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)

Incidental

Sedimentary > Carbonate > Limestone (Bed)

Comments

In North, central, and south Texas including Quaternary for all of west Texas- Shale, siltstone, and limestone; upper part limest. and shale, ls lt-yellowish-brown, flaggy; lower part, siltst. and v. fine-grained sandst., lt-yellow to gray, laminated flaggy, some limestone, silty, med-brown, laminated, thickness 75-200 ft, thins NEward. In East Texas and Gulf Coast to Rio Grande- Shale and limestone. Upper part-- shale, compact, silty, contains fossil fish teeth and bones, 10 ft or more thick; middle part-- silty limest grading to calcar siltst, med gray weathers pale yellowish-brown, flaggy; lower part--shale, calcareous, dk gray, 7-50 ft thick. Thickness of Eagle Ford Formation 25-65 ft. In Texarkana Sheet (1966) thickness 60 ft feathers out east. In Sherman Sheet (1967) (NE Texas) shale, selenitic, bituminous, calcar concretions and septaria, thin platy beds of sandst. and sandy ls. in middle and upper part, med to dk gray; marine megafossils; thickness 300-400 ft.

References

Bureau of Economic Geology, 1977, Del Rio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000.

Bureau of Economic Geology, 1966, Texarkana Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000.

Bureau of Economic Geology, 1967, Sherman Sheet, Geologic Atlas of Texas: University of Texas at Austin, Bureau of Economic Geology, scale 1:250,000.

Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000.

NGMDB product

NGMDB product page for 68390

Counties

Bell - Collin - Comal - Dallas - Denton - Edwards - Ellis - Fannin - Grayson - Hays - Hill - Johnson - Kinney - Lamar - McLennan - Medina - Red River - Tarrant - Uvalde - Val Verde - Williamson