56o A. F. FOERSTE 



hard, white limestone, and was formerly quarried at Cedar Point. 

 It is unconformably overlaid by brown rock, 2 feet thick. At 

 the Taylor quarry, one and a half miles northeast of Iron City, 

 along the railroad line to Columbia, the Louisville bed is exten- 

 sively quarried. It is unconformably overlaid by the Black shale 

 series, consisting, in ascending order, of deep brown shaly rock, 

 6 inches thick ; greenish, fine-grained Hardin sandstone, i 5 inches 

 thick; fissile Chattanooga black shale, 6 inches thick; greenish 

 shale similar to the greenish shales above the black shale south- 

 west of Mount Pleasant, 10 inches thick; and a layer of phos- 

 phatic nodules. In the railroad cut through Iron city, now 

 abandoned, some of the heavier beds in the lower part of the 

 Waverly contain plant remains. 



The coarse, cross-bedded limestone at Riverside and Iron City, 

 referred to the Clinton, suggests that these localities were, not 

 far distant from the shoreline at the beginning of the Silurian 

 period. This suggestion is apparently corroborated by an out- 

 crop about half a mile east of Cedar Point. Here the road 

 leading eastward from Cedar Point crosses the railroad to Colum- 

 bia. In a dry run along the southern side of the road, about a 

 hundred feet east of the railroad, a coarse conglomerate bed, 

 about I foot thick, is exposed. Some of the pebbles are 3 inches 

 long. This conglomerate is referred to the Clinton. It rests 

 upon a bluish, thin-bedded limestone, interbedded with more 

 shaly material, referred to the Ordovician. 



Careful search in the valleys of Brush and Bluff Creeks, 

 northeast of Waterloo, in Alabama, failed to reveal any Devonian, 

 Silurian, or Ordovician rocks in the areas credited with rocks 

 beneath the Subcarboniferous horizon, on the geological map of 

 Alabama, published in 1894. 



B. SILURIAN STRATA IN THE TENNESSEE RIVER VALLEY, 

 I. CLINTON, OSGOOD, LAUREL, AND WALDRON BEDS. 



3. New Era, Glenkirk, Clifto?i, Swallow Bluff, Maddox mill, 

 Wayjiesboro. — The most northern exposures of Ordovician rocks 

 along the Tennessee River occur between the mouth of Cedar 

 Creek and New Era. 



