GROUND WATER IN NORTH-CENTRAL TENNESSEE

Not known.
5-107.
Bidgetop shale.
Topmost beds supply many so-called chalybeate
and sulphur springs in zone of rock
weathering along Highland Rim escarpment;
not generally water bearing beneath cover.
Basal sandstone member may be source of
ground water in eastern Dickson County and
vicinity.
Light-blue to green clay which Incloses several
thin beds of earthy sandstone, earthy limestone,
and chert; green phosphatie shale
(Maury glauconitic member) at base.
Black fissile carbonaceous shale with thin seams
of bituminous matter and disseminated small
crystals of pyrite; Hardin sandstone member
locally at base.
Heavy-bedded light-gray limestone 12 feet thick,
locally, with a basal member of white or brown
coarse fossiliferous sandstone. Not widespread.
Alternating layers of dense bluish-gray limestone
and yellowish chert, each 2 to 9 inches thick,
known only at two localities in southern Humphreys
County.
White, gray, and buff nonfossiliferous cherty
limestone; known only in the Wells Creek
Basin, Stewart County.
Thin-bedded and somewhat cherty fossiliferous
limestone; known only in the Wells Creek
Basin, Stewart County.
Heavy-bedded light-gray, relatively pure limestone.
Thin-bedded earthy limestone and variegated
shale.
0-46.
Chattanooga shale.
Mississippiail
or Upper
Devonian.
Carboniferous
or Devonian.
0-35.
Pegram limestone.
Middle Devonian.
46+.
Camden chert.
Devonian.
20-40.
Harriman (?) chert.
Oriskany