1884.] 14o [Stevenson. 



IV. THE AREA DRAINED BY CLINCH RIVER. 



The turnpike, from Abingdon to "Wise Court-House, crosses tbe ridge be- 

 tween Tarr's fork of Big Moccasin creek and a branch of Copper creek at 

 a little way above Mr. G. W. Morton's house. Tbe rate of dip increases 

 rapidly in Knox limestones until at that house it becomes sixty degrees. 

 There tbe Copper Creek fault is crossed and tbe shales are shown on tbe long 

 grade. The dip gradually diminishes and the marbles, first reached near 

 tbe Sulphur Spring Church, remain in sight to tbe old Court-House, beyond 

 which the underlying vvhite chert and its ferruginous earth are exposed; 

 As usual, the lower members of the marble group contain great nodules 

 of black chert. Same of the marbles near Williams' store are of decided 

 beauty. 



Fossils are very rare, but a somewhat earthy bed on Copper ridge, not 

 far from Dickensonville, on the road to Osborn's ford, contains Orthis 

 pectinella, 0. lynx, Strophomena alternata and some bryozoans. 



The dips are almost regularly south of south-east on both Moccasin and 

 Copper ridge until within about seven miles of Osborn's ford on the latter 

 ridge, where a north-westward dip is distinct. There is difficulty in deter- 

 mining the structure along the crest of Copper ridge, because the rocks 

 are deeply buried by tbe coating of decomposed material usually contain- 

 ing brown hematite, and always of a deep red color. At little more than 

 a mile and a half from Osborn's ford the dip becomes very irregular, and 

 the cherty limestones and calcareous sandstones are thrown into many 

 and close folds, a condition which is continuous thence to considerably 

 beyond the ford on the road to Guest's station ; but all exposures cease in 

 the broad " bottom " at about half a mile Irom tbe ford, so that the rela- 

 tion of the Knox limestone to the Lower Coal measures (Quinnimont) 

 cannot be ascertained directly. 



The "Hanging Rock" on Little Stony creek, at about a mile from 

 Clinch river, is a massive sandstone belonging to the Lower Coal meas- 

 ures ; it dips north of north-west at between sixty and seventy degrees, and 

 tbe thickness as exposed is not far from seventy feet. The rock contains 

 some conglomerate layers, and it is said to be underlaid by coal. This 

 wall is clearly at some distance north from tbe Clinch fault, as for not less 

 tlian fifty rods below it the hillsides show great blocks of sandstone, and 

 a somewhat indefinite exposure seems to show the sandstone in place. 



The '• blossom" of a coal bed was seen at tbe sharp bend of the road, 

 one-fifth mile beyond the wall. The bed appears to be one foot thick ; it 

 has shales below and a soft massive sandstone at a very few feet above. So 

 far as exposed, the rocks have northerly dip until the open space beyond 

 Buckner's ridge is reached, where exposures show the dip to be south of 

 south-east. Thence to the summit of this Powell-Stone mountain no expo- 

 sures were seen aside from fragmentary exhibitions of shale and sand- 

 stone. The broad, very gently undulating summit of tbe mountain is 

 formed by a massive Quinnimont sandstone, fully ninety feet thick, and 



FROC. AMER. PHILOS. SOC. XXII. 118. S. PRINTED MARCH 2, 1885. 



