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Mineral Resources > Online Spatial Data > Geology > by state > Tennessee Geology

Geologic units in Fentress county, Tennessee

[Additional scientific data in this geographic area]

Crab Orchard Mountains Group (Pennsylvanian) at surface, covers 4 % of this area

Crab Orchard Mountains Group - Only the lowest formation of the group, the Sewanee Conglomerate, is preserved in the area of this sheet. Sewanee is gray to brown, medium- to coarse-grained conglomeratic sandstone, with a thin zone of ferruginous quartz- and shale-pebble conglomerate at base. Maximum preserved thickness 35 feet.

Lithology: conglomerate; sandstone

Bangor Limestone and Hartselle Formation (Mississippian) at surface, covers 4 % of this area

Bangor Limestone - Dark brownish-gray limestone, thick-bedded. Thickness 100 to 250 feet; and Hartselle Formation - Thin-bedded, fine-grained sandstone and greenish-gray shale interbedded with coarse limestone. Thickness 0 to 60 feet.

Lithology: limestone; sandstone; shale

Gizzard Group including Warren Point Sandstone and Raccoon Mountain Formation (Pennsylvanian) at surface, covers 0.3 % of this area

Gizzard Group - Sandstone, conglomeratic sandstone, siltstone, shale, and minor coal. Thickness 100 to 200 feet. Includes Warren Point Sandstone - Gray to brown sandstone and minor conglomeratic sandstone. Thickness 60 to 160 feet; Raccoon Mountain Formation - Siltstone, sandstone, shale, and minor coal. Thickness 0 to 65 feet.

Lithology: sandstone; shale; siltstone; coal

Fentress Formation (Pennsylvanian) at surface, covers 11 % of this area

Fentress Formation - Mostly dark-gray to light-brown shale, with minor siltstone and sandstone. Wilder coal near middle. Laterally equivalent to entire Gizzard Group and all of Crab Orchard Mountains Group below Rockcastle Conglomerate. Thickness as much as 340 feet.

Lithology: shale; siltstone; sandstone; coal

Crooked Fork Group (Pennsylvanian) at surface, covers 2 % of this area

Crooked Fork Group - Shale, sandstone, siltstone, and thin coal beds; from top down group includes Poplar Creek coal, Wartburg Sandstone, Glenmary Shale, Coalfield Sandstone, Burnt Mill Shale, Crossville Sandstone, and Dorton Shale. Thickness 200 to 450 feet.

Lithology: sandstone; shale; siltstone; coal

Monteagle Limestone (Mississippian) at surface, covers 7 % of this area

Monteagle Limestone - Fragmental and oolitic limestone, light-gray; and fine-grained, brownish-gray limestone. Thickness 180 to 350 feet.

Lithology: limestone

Fort Payne Formation (Mississippian) at surface, covers 0.6 % of this area

Fort Payne Formation - Bedded chert, calcareous and dolomitic, somewhat crinoidal; and minor shale. Thin green shale (Maury) at base. Average thickness about 200 feet.

Lithology: chert; shale

St. Louis Limestone and Warsaw Limestone (Mississippian) at surface, covers 5 % of this area

St. Louis Limestone - Residuum of nodules and blocks of chert in sandy clay. (Originally grayish-brown, medium-bedded limestone.) Maximum preserved thickness about 50 feet. Warsaw Limestone - Residuum of porous chert blocks in sandy clay. (Originally gray, medium- to coarse-grained, thick- bedded limestone.) Thickness about 60 feet.

Lithology: clay or mud; chert

Pennington Formation (Mississippian) at surface, covers 6 % of this area

Pennington Formation - Highly variegated clay shale, distinctive; contains siltstone and locally gray, fine-grained sandstone. Thickness 400 to 700 feet.

Lithology: shale; siltstone; sandstone

Rockcastle Conglomerate (Pennsylvanian) at surface, covers 59 % of this area

Rockcastle Conglomerate - Conglomeratic sandstone and sandstone, gray to brown, fine- to coarse-grained. Thin coal-bearing shale locally present near middle. Thickness 150 to 220 feet.

Lithology: conglomerate; sandstone; shale; coal