138 THE CAMBRIAN. [bum,. 81: 



upon the pre-Paleozoic rocks, the quartzite in turn resting upon the 

 shales. This makes the .limestones represent the Great Valley lime- 

 stone of Virginia or the Oalciferous-Ohazy-Trenton belt ; the shales, the 

 Hudson series, and the sandstone, the Medina series of the New York 

 section. 1 



♦NORTH CAROLINA. 



As now known the Cambrian rocks of North Carolina are confined to 

 J;he extreme western boundary, where the Ocoee conglomerate and 

 Chilhowee sandstone series extend across from Tennessee. This was 

 recoguized by Prof. J. M. Safford in his work in Tennessee ; and Prof. 

 W. C. Kerr notes the occurrence of thin-bedded, siliceous slates at Paint 

 Eock, on the State line. He says of them : . 



They are called by Prof. Safford, the geologist of the State of Tennessee, Chil- 

 howee sandstones, and are set down conjecturally by several eminent geologists as 

 Potsdam sandstone. They have never yielded any fossils by which their geological 

 horizon might be determined. A few very thin beds of argillaceous slate are found 

 interpolated here and there between the quartzose strata. 



Passing up the deep gorge which the river has excavated, the qaartzites are soon 

 found to be interbedded with and are finally replaced by shales and grits, the latter 

 generally fine, but occasionally approaching in appearance a breccia or conglomerate. 

 These are succeeded by heavy beds of argillaceous slates and shales, which in turn 

 give place, at Warm Springs, to a heavy bedded blue and gray limestone. This is 

 followed by a calcareous, compact, fine-grained sandstone, which presently passes 

 into a gray, much jointed quartzite rising in, vertical clifl's along the river for 2 miles, 

 and succeeded by a well characterized coarse conglomerate with bluish gray slates 

 and shales, at and below the mouth of Laurel River. A little above this point comes 

 in a very extensive and conspicuous bed of feldspathic quartzite, or petrosilex, which 

 continues for more than a mile, and then graduates through a gneissoid rock into a 

 series of gray, drab, and mottled argillaceous slates and shales. This succession of 

 quartzites, grits, shale, limestone, and conglomerate occupies in direct cross section 

 a space of more than 10 miles. I have elsewhere referred to the identity of this for- 

 mation with that which is so conspicuous on Valley River, and shall therefore call it 

 the Cherokee Slates. They pass in a northeast course up the Laurel Valley and 

 through the Smoky or Unaka Mountains into Tennessee. 3 



In a note on the occurrence of metamorphic Silurian rocks in North 

 Carolina, Prof. F. H. Bradley states that the rocks about Franklin are 

 of Lower Silurian age, and the marbles of Murphy and vicinity are the 

 equivalents of the Knox limestones of Tennessee, which are of Quebec 

 group age. 3 This statement of Prof. Bradley's is noted here, as it is 

 probable that the formations examined by him are equivalent to those 

 exposed on the French Broad, between Warm Springs, North Carolina, 

 and Paint Rock. If so, they may be of Cambrian age. In a paper pub- 

 lished the following year, Prof. Bradley refers 4 to the strata in the 

 vicinity of Murphy, in southwestern North Carolina, and takes the view 



^ull. Geol. Soc. America, vol. 2, 1891, pp. 155-163. 



2 Report of the State Geologist of North Carolina. Raleigh, 1869, p. 29. 



s Note on the occurrence of metamorphic Silurian rocks in North Carolina. Am. Jour. Sci., 3d ser., 

 Vol. 8, 1874, p. 390. 

 4 On the Silurian age of the southern Appalachians. Am. Jour. Sci., 3d ser., vol. 9, 1875, pp. 286, 382. 





