SILURIAN-DEVONIAN UNCONFORMITY 411 



posed. Southeast of Sam Walker's house (locality 10), along the river 

 and about three-fourths of a mile west of Foster and Creighton's switch 

 (locality 11), the Pegram limestone rests on Louisville limestone having 

 a thickness of 28 to 30 feet. At the bridge, a mile and a half west of 

 Pegram, the Pegram limestone rests on an unknown thickness of Louis- 

 ville limestone. Including the softer, more shaly courses at the top of 

 the section, at least 30 feet of Louisville rock are exposed south of the 

 railroad ; adding the strata exposed in the ravine extending north from 

 the railroad, the total thickness may exceed 50 feet. The Waldron shale 

 belongs stratigraphically at a still lower horizon, but it is not exposed 

 here. 



While at Newsom (locality 12) 32 feet of Louisville limestone intervene 

 between the Pegram limestone and the Waldron shale, at the quarry south 

 of J. V. Linton's house (locality 15) the Black shale rests directly on the 

 top of the Laurel limestone, the Louisville limestone and Waldron shale 

 being absent. About 2 miles southward, where the road to Fernvale 

 crosses the creek, half a mile beyond the house of James A. Linton, Jr. 

 (locality 16), the Laurel limestone and the Osgood bed are also absent, 

 so that the Black shale rests on 16 feet of cherty Clinton [limestone. 

 Just north of a little branch a quarter of a mile south of the home of 

 James Linton, Sr. (locality 17), most of the Clinton even is absent, the 

 thickness of the Clinton (cherty limestone) beneath the Black shale 

 being only 2 feet. A mile farther south, at the school-house, the Black 

 shale rests on Ordovician rocks. 



The Johnson V. Linton locality is about half a mile south of the 

 Linton post-office or the Elliston store. As stated in the last paragraph, 

 the Black shale here rests on the top of the Laurel limestone. About 

 a mile eastward, on the road to Tank, an eighth of a mile before reach- 

 ing a negro church, the hillside north of the road is covered with frag- 

 ments of chert containing a fair number of Clinton fossils. The highest 

 chert fragments are found 23 feet above the road, and since the Black 

 shale is seen only 38 feet higher up, resting on limestone containing 

 Pisocrinus gemmiformis, it is probable that the Black shale here also rests 

 on the top of the Laurel limestone. However, at the foot of the hill, 

 half a mile west of Tank, above the spring south of the home of W. M. 

 Forehand (locality 13), only 3 feet of cherty Clinton limestone are seen 

 beneath the Black shale. For 10 feet below the Clinton exposure the 

 rock is covered. This part of the section is probably occupied by the 

 soft clayey layers, which are quite characteristic of the top of the Ordo- 

 vician in the area west of Franklin. 



At the Oil well, a short distance south of Tom Fox's house (locality 

 18), along a branch of Leipers creek the Black shale rests on 6 feet of 



LVIX— Bull. Geol. Soc. Am,, Vol. 12. 1900 



