GROUND WATER IN NORTH-CENTRAL TENNESSEE

198 GBOUND WATEB IN NOBTH-CENTRAL TENNESSEE
Driller's partial log of Midwest Tennessee Oil Co.'s well on Marvin Milton property
[No. 34, pi. 4. So-called Standing Rock Well; casing head about 430 feet above sea level; total depth, 1,636
feet]
Feet
Soil_______ --_ ._._ _ _. _..___._--_-_ 0-30
Chert, dense__--__._._._._.___________.___ 30-164
Shale, black (Chattanooga shale)____._._._____ 164-239
Limestone, white and brown, water bearing. _______ 239-375
Limestone, petroliferous.__________________ ._._ 375-380
Limestone, dense, brown_ ._._._._._.___._._._._._ 380-495
Shale, blue.--_-_._-_-_.___-________---__________ 495-597
Limestone, white__-_._._._._._.____-__-_______ 597-602
Limestone, gray____-_-_._-___._._._._.___ 602-608
Limestone, brown_________________________ 608-612
Limestone, red_________________________ 612-670
Limestone, white_______________._._._._._._ 670-696
Shale, green____________.____ _______ 696-706
Limestone and shale, brown___-----_-____________ 706-742
Limestone, red_________-___._._.--_-_._-_.___ 742-904
Limestone, white____________ ___._._._ 904-924
Limestone, darkblue___________ 924-1,129
Limestone, gray______________________ 1,129-1,220
SUMNER COUNTY
[Area, 663 square miles. Population, 28,6221
GENERAL FEATURES
Sumner County, which occupies the northeast corner of the region
covered by this report (pi. 1), is bounded on the west by Robertson
County, on the southwest by Davidson County, and on the south by
Wilson County. Its county seat and principal commercial center is
Gallatin (population, 3,050).
Sumner County is divided into two physiographic districts of
nearly equal area by the Highland Rim escarpment; to the north lies
the Highland Rim plateau; to the south lies the northern lobe of the
Nashville Basin (pp. 16-18). In this county the Highland Rim pla­
teau is a very gently undulating plain which slopes northward from
an altitude of about 900 feet above sea level along its southern edge
to about 775 to 880 feet in the northwestern part of the county.
This plain is drained northwestward by subparallel mature valleys trib­
utary to the Red and Green Rivers, branches of the Cumberland and
Ohio Rivers, respectively. (See pi. 3.) Undrained depressions and
sink holes are common in many parts of the plain. The Highland
Rim escarpment is a southward-facing dissected scarp from 350 to
400 feet high which embraces a belt of rugged topography from 4 to
1% miles wide produced by the northward advance of Mansker,
Drake, Station Camp, and Bledsoe Creeks, subparallel tributaries of
the Cumberland River. Its general trend within the county as de­
fined by a line tangent to the points of protruding spurs is approxi-