Geologic units in Grayson county, Texas

Eagle Ford Formation (Late Cretaceous) at surface, covers 27 % of this area

Eagle Ford Formation

Woodbine Formation (Late Cretaceous; Gulfian Series) at surface, covers 25 % of this area

Woodbine Formation

Austin Chalk (Late Cretaceous; Gulfian Series) at surface, covers 25 % of this area

Austin Chalk

Terrace deposits (Pleistocene and Holocene) at surface, covers 5 % of this area

Terrace deposits

Gober Chalk and Roxton Limestone (Late Cretaceous; Gulfian Series) at surface, covers 4 % of this area

Gober Chalk and Roxton Limestone

Alluvium (Holocene) at surface, covers 4 % of this area

Alluvium

Pawpaw Formation, Weno Limestone, and Denton Clay, undivided (Early Cretaceous) at surface, covers 3 % of this area

Pawpaw Formation, Weno Limestone, and Denton Clay, undivided

Fort Worth Limestone and Duck Creek Formation, undivided (Early Cretaceous) at surface, covers 3 % of this area

Fort Worth Limestone and Duck Creek Formation, undivided

Bonham Formation (Late Cretaceous; Gulfian Series) at surface, covers 2 % of this area

Bonham Formation

Grayson Marl and Main Street Limestone, undivided (Early Late Cretaceous and Late Early Cretaceous) at surface, covers 1 % of this area

Grayson Marl and Main Street Limestone, undivided

Ector Chalk (Late Cretaceous; Gulfian Series) at surface, covers 1 % of this area

Ector Chalk

Goodland Limestone and Walnut Clay, undivided (Early Cretaceous; Comanchean Series) at surface, covers 0.5 % of this area

Goodland Limestone and Walnut Clay, undivided

Kiamichi Formation (Early Cretaceous; Comanchean Series) at surface, covers 0.4 % of this area

Kiamichi Formation

Antlers Sand (Early Cretaceous) at surface, covers 0.3 % of this area

Antlers Sand

Alluvium (Holocene) at surface, covers < 0.1 % of this area

WOODWARD- Lenticular and interfingering deposits of gravel, sand, silt, and clay. Generally light-tan to gray. Thickness along major streams ranges up to 100 feet and probably averages 40 feet; along minor streams the thickness ranges up to 45 feet and probably averages 20 feet. ENID- Sand, silt, clay, and locally gravel. Maximum thickness ranges from 30 to 80 feet (9 to 24 m) along major streams and from 0 to 60 feet (0 to 18 m) along minor streams. TULSA- Gravel, sand, silt, and clay. TULSA- Gravel, sand, silt, and clay. OKLAHOMA CITY- Sand, silt, clay, and lenticular beds of gravel. Thickness ranges from about 30 to 100 feet and probably averages about 50 feet along major streams. Along minor streams, thickness ranges from a few feet to about 50 feet and probably averages about 25 feet. LAWTON- Sand, clay, and gravel as much as 50 feet (15 m) thick; Shown only along major streams and tributaries. ARDMORE-SHERMAN- Gravel, sand, silt, and clay, including low terraces; thickness, about 25 to 100 feet. McALESTER TEXARKANA- Gravel, sand, silt, and clay, including low terraces about 30 feet above channels; thickness, about 50 feet along Little River and 110 feet along Red River.

Caddo Formation (Early Cretaceous) at surface, covers < 0.1 % of this area

ARDMORE-SHERMAN-Limestones, marls, and shales; 150 feet thick. Subdivided into "Fort Worth Limestone" at top and "Duck Creek Limestone" below. McALESTER TEXARKANA- Limestones, white to cream, silty, alternating with gray shales, with "Texigryphaea washitaensis;" 7-foot bed at top (Fort Worth equivalent) and blue-gray silty shales and limestones below with "Texigryphaea navia" (Duck Creek equivalent); thickness, 150 feet. Ouachita Mountain uplift; S. OK folded belt province.

Antlers Sand or Antlers Sandstone (Early Cretaceous) at surface, covers < 0.1 % of this area

ARDMORE-SHERMAN- "Antlers Sand" Sand, white to yellow, medium-grained, weakly indurated, with varicolored clays. Contains arkosic conglomerates near Arbuckle Mountains and "Baum Limestone" near Mannsville anticline. Thickness, 200 to 700 feet. McALESTER TEXARKANA- "Antlers Sandstone" Sandstone and sand, white to reddish-yellow to orange-brown to gray, fine- to coarse-grained, quartzose, crossbedded, moderately to weakly indurated, interbedded with varicolored clays and conglomerates; contains fossil wood and dinosaurs; rests unconformably upon Ouachita rocks but conformably upon DeQueen Limestone; thickness, 0 to 320 feet, thickening southeastward to 900 feet in subsurface.