Geologic units in Fannin county, Texas

Gober Chalk and Roxton Limestone (Late Cretaceous; Gulfian Series) at surface, covers 23 % of this area

Gober Chalk and Roxton Limestone

Terrace deposits (Pleistocene and Holocene) at surface, covers 17 % of this area

Terrace deposits

Bonham Formation (Late Cretaceous; Gulfian Series) at surface, covers 16 % of this area

Bonham Formation

Ozan Formation (Late Cretaceous; Gulfian Series) at surface, covers 13 % of this area

Ozan Formation

Eagle Ford Formation (Late Cretaceous) at surface, covers 10 % of this area

Eagle Ford Formation

Alluvium (Holocene) at surface, covers 10 % of this area

Alluvium

Brownstown Marl (Late Cretaceous; Gulfian Series) at surface, covers 4 % of this area

Brownstown Marl

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

Blossom Sand

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

Wolfe City Formation

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

Ector Chalk

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

Woodbine Formation

Pecan Gap Chalk (Late Cretaceous; Gulfian Series) at surface, covers 0.9 % of this area

Pecan Gap Chalk

Marlbrook Marl (Late Cretaceous; Gulfian Series) at surface, covers < 0.1 % of this area

Marlbrook Marl

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.

Woodbine Formation (Late Cretaceous) at surface, covers < 0.1 % of this area

McALESTER TEXARKANA- Sand, dark-green, yellowish-red, white, gray, fine- to coarse-grained, tuffaceous in upper part; crossbedded, quartzose, and brownish-red noncalcareous clay; some gravel lentils with little to no quartz and some lignites and fossil plants; rests unconformably upon successively older Cretaceous units eastward; thickness, 325 to 455 feet, increasing eastward.