10 GEOLOGY AND MINERAL RESOURCES OF MISSISSIPPI. 
Three-fourths of a mile north of the bridge at the old McMaster mill the dark-blue lime- 
stone is well exposed in the creek and road. At this place the overlying soil has been 
removed, leaving half an acre or more of the rock exposed. There are in the limestone two 
well-marked sets of joints. The main set extends N. 25° E. and a secondary set is practically 
at a right angle to the first. Overlying the dark-blue limestone are about 25 to 30 feet of 
angular flint and hornstone.. 
Along Whetstone Creek, which empties into Tennessee River east of Short post-office, the 
following section is shown : 
Section on A. L. Bugg's land at mouth of Whetstone Creek, near Short. 
Feet. 
4. Angular chert, flint, and hornstone, devoid of fossils 100 
3. Dark-colored shale containing iron pyrite; very fossiliferons in lower part .SO 
2. Dark-blue nonfossiliferous limestone, with well-marked joints trending N. 20° E 20 
1. Thin-bedded, fine-grained, shaly limestone, with thin bands of fine-grained sandstone or whet- 
stone varying from a fraction of an inch to 12 inches in thickness 20 
No. 3 of this section perhaps represents the top of the Devonian. Unfortunately the fos- 
sils coming from this stratum were lost, so that the exact horizon can not at present be 
determined. The siliceous chert hero and at McMaster's mill represents the lowest member 
of the Carboniferous and rests on the Devonian shale. 
Farther south, near the mouth of Bear Creek, the siliceous chert bed continues to thicken, 
reaching a maximum thickness of 150 feet. Here the chert, as at Whetstone Creek, caps 
the tops of the hills. Still farther south along Bear Creek the St. Louis and Chester forma- 
tions occur at a higher altitude. Fig. 1 (p. 7) shows the relations of the New Scotland beds 
to the later formations. There is a very perceptible dip of the older rocks to the south. 
A well section at the mouth of Bear Creek shows 160 feet of shaly, dark-colored limestone, 
1-10 feet of dark-gray shale, and 4.50 feet of gray limestone. The gray limestone is no doubt 
the equivalent of the gray limestone at the mouth of Yellow Creek, where the New Scotland 
fauna was collected. The well was begun in the limestone at the foot of the hill, the top of 
which is covered witli siliceous chert. 
MISSISSIPPIAN (LOWER CARBONIFEROUS). 
Overlying the Devonian rocks is the Mississippian (Lower Carboniferous) series of cherts, 
limestones, sandstones, and shales. The thickness of these beds in Mississippi is not known, 
but is perhaps 800 or 900 feet. The beds are comparatively little disturbed, with a south- 
ward dip of about 40 feet per mile and a westward dip of about 20 feet per mile. The Car- 
boniferous rocks represent the southwestern extremity of the southern Appalachian plateau, 
whose southern and western slopes are overlapped by the later formations. 
TULLAHOMA FORMATION. 
The lowest formation of the Mississippian series consists of 130 to 150 feet of angular frag- 
ments of chert or flint which is correlated with the Tullahoma or Lauderdale chert of the 
Alabama survey. It is thickest near the mouth of Bear Creek and thins to the north. 
The group in Alabama is described by MeCalley as a siliceous chert, interbedded with 
argillaceous and calcareous shales, containing beds of limonite ore. The principal mate- 
rials in Mississippi are highly siliceous fragmental chert, pulverized silica, and residual clay. 
In its unweathered condition the chert is stratified, but near the surface it occurs in angular 
fragments varying in size from sand grains to bowlders weighing tons. In places the chert 
has weathered into beds of snow-white or yellow pulverulent silica. Near the mouth of Bear 
Creek are large bodies of it which were mined for several years for an abrasive. Near the 
surface the silica often forms a white to yellowish clay or kaolin. A fine grade of china ware 
has been made from a deposit of this clay on Whetstone Creek. 
aRept. Geol. Survey of Alabama, pt. 1, Tennessee Valley Region, p. 35. 
