448 A. W. GRABAU PALEOZOIC DELTA DEPOSITS OF NORTH AMERICA 



the Chilhowee Mountain region, it reaches a thickness of 1,100 feet, and 

 it here is a good red sandstone, and contains considerable feldspar, being 

 at times an arkose. It is succeeded by the Clinch sandstone, of which, 

 however, only a single slight mass, 6 feet in thickness, remains. The 

 Clinch, or in its absence the Bays, is disconformably succeeded by the 

 Chattanooga shale, there being no Eockwood preserved here. Northeast- 

 ward, along the strike of the strata in the Morristown and Grenville 

 quadrangles (numbers 27 and 118) near the Virginia line, we come to 

 the type section in Bays Mountain, in Hawkins and Green counties, 

 Tennessee. Here the formation is only from 300 to 500 feet thick and 

 consists of a red calcareous and argillaceous sandstone, resting with ap- 

 parent conformity upon the Sevier shale, which is here 1,500 to 2,500 or 

 3,000 feet thick, and contains beds of calcareous sandstone in the upper 

 part, which forms a gradation into the Bays sandstone. It is interesting 

 to note that reddish sandstones, the Tellico, occur low down in the 

 Sevier, showing apparently the general existence at the beginning of 

 Upper Ordovicic time of the conditions which became so marked toward 

 its close. Throughout its outcrop in the section the Clinch sandstone 

 succeeds the Bays with a thickness of several hundred feet, while the 

 Eockwood here is essentially a shale. In the southwest end of the Bays 

 Mountains the Bays sandstone is reported as more or less interbedded 

 with the white Clinch sandstones near the top, though usually the for- 

 mations are sharply separated. From these strata Keith says Silurian 

 brachiopods have been obtained, but from his statement it is not clear 

 whether these are in the transition beds and true Siluric species or in 

 the basal beds and "Lower Silurian" or Ordovicic species. Ulrich, in 

 his correlation table, makes the typical Bays sandstone of Upper Black 

 Eiver and Lower Trenton age, but gives no reason for such correlation. 

 While it is not impossible that an earlier red series occurred in the Ten- 

 nessee region (witness the Tellico sandstone and the Eed Moccasin lime- 

 stone), the fact that the Bays of the type section rests on a great develop- 

 ment of Sevier shale, with which it forms a continuous depositional 

 series, and that the Bays elsewhere in this region is of Lorraine and 

 later age indicates that, so far as this sandstone is concerned, it is all of 

 Upper Cincinnatian age. Xorthward and westward the Bays sandstone 

 becomes more calcareous and thinner. While having a general thickness 

 of 500 feet in Clinch Mountain, its thickness northwest of this section 

 is seldom more than half that amount. Here as elsewhere the Sevier 

 grades upward into the Bays, beds of reddish sandstone appearing in the 

 upper part of the Sevier, followed by fossiliferous shales and limestones. 

 In the Powell Valley, at the base of Cumberland Mountain in north- 



