GROUND WATER IN NORTH-CENTRAL TENNESSEE
GROUND WATER IN NORTH-CENTRAL TENNESSEE
GROUND WATER IN NORTH-CENTRAL TENNESSEE
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44 <strong>GROUND</strong> <strong>WATER</strong> <strong>IN</strong> <strong>NORTH</strong>-<strong>CENTRAL</strong> <strong>TENNESSEE</strong><br />
LOWER DEVONIAN SERIES<br />
Rocks of Lower Devonian age are known at two localities in the<br />
Wells Creek Basin, Stewart Comity, but have not been identified<br />
elsewhere in north-central Tennessee.<br />
HARRIMAN (?) CHERT<br />
At one of these localities, in the south bank of the Cumberland<br />
River about 1 mile southwest of Cumberland City, white, gray, and<br />
buff cherty limestone as much as 40 feet thick crops out above the<br />
Birdsong limestone. It is generally very poorly exposed. Foerste 82<br />
has suggested that this cherty limestone may be correlative with the<br />
Camden chert, of Middle Devonian age, but Dunbar M has correlated<br />
it provisionally with the Harriman chert, of Lower Devonian (Oris-<br />
kany) age, on the basis of a single valve of Spirifer murchisoni?.<br />
The detailed stratigraphic relations and area! extent of the Harri<br />
man formation in north-central Tennessee are not known.<br />
BIRDSONG LIMESTONE<br />
At the other locality of Lower Devonian rocks, which is at the top<br />
of a section in a railroad cut about 3 miles southwest of Cumberland<br />
City, Foerste 84 has identified limestone of the Linden group, of<br />
Helderberg age. Dunbar 85 has correlated this limestone with the<br />
Birdsong shale, and Bucher 86 has recognized in it such Helderberg<br />
fossils as Atrypa reticularis, Leptostrophia beckii, a small Delthyris,<br />
and Meristella. According to Dunbar, the formation overlaps east<br />
ward upon the Silurian rocks and is generally absent by erosion east<br />
of the Tennessee River. In the Wells Creek Basin it is represented<br />
by 10 to 20 feet of thin-bedded and somewhat cherty limestone,<br />
which is not commonly well exposed. The areal extent of this strati-<br />
graphic unit in north-central Tennessee has not been traced.<br />
SILURIAN SYSTEM<br />
The rocks of Silurian age that crop out on the Western and north<br />
western flanks of the Nashville dome (see pp. 62-63) in Tennessee<br />
constitute a classic section which has long been a field of paleonto-<br />
logic and stratigraphic study and which has been studied in detail<br />
«8 Foerste, A. F., Silurian and Devonian limestones of western Tennessee: Jour. Geology, vol. 11, p. 693,<br />
1903.<br />
M Dunbar, C. O., op. cit., p. 74.<br />
M Foerste, A. F., op. cit. (1903), pp. 690-692.<br />
M Dunbar, C. O., op. cit., p. 58.<br />
* Bucher, W. H., The stratigraphy, structure, and origin of Wells Creek Basin, Tenn.: Tennessee Dept.<br />
Education Div. Geology [in preparation].