LIMESTONES OF WESTERN TENNESSEE 571 



On the geological map of Alabama published in 1894, Chat- 

 tanooga black shale and Ordovician limestone are recorded as 

 occurring in the valleys of Brush (Four Mile), and Bluff Creeks, 

 southwest of Whittens Stand, within 6 miles of the Tennessee 

 state line. A careful examination of these valleys revealed 

 nothing lower than the Subcarboniferous. At the Taylor quarry 

 northeast of Iron City, the lower part of the Lego bed, 19 feet 

 thick, is directly overlaid by the Black shale series, and, at 

 another locality, by the Waverly. 



West of the line of eastern outcrops here enumerated the 

 Brownsport bed is exposed at the proper horizon at all points 

 where not removed by Cretaceous and Tertiary erosion. The 

 thickest sections are found farthest westward in that part of the 

 area in which the Brownsport bed is directly overlaid by the 

 Chattanooga black shale series. This is evidently the area east 

 of the line of outcrop of the Linden or Helderbergian limestones 

 and shales, A study of the outcrops within this area indicates 

 that the Brownsport bed is unconformably overlaid by the Chatta- 

 nooga black shale series. If the thinning out of the Brownsport 

 bed eastward is due to erosion in times preceding the Mesode- 

 vonic, the Brownsport bed may formerly have extended much 

 farther eastward, up the western flank of the Cincinnati geanti- 

 cline. 



8. Perry ville, Linde?i, Lego, New Era, Clifto?i, Cerro Gordo, 

 Brownsport. — At Perryville the upper part of the Brownsport bed 

 is quarried. Astraeospo?igia me?nsais occurs at the top, imme- 

 diately beneath the Linden limestone. The upper part of the 

 Brownsport bed is formed by hard limestone also a mile north 

 of Linden, north of the home of William Patton, and thence 

 eastward, forming a bluff 52 feet high along a branch entering 

 the Buffalo River. Here Astraeospojigia meniscus occurs again at 

 the'^top, immediately beneath the Linden limestone, associated 

 with Caryomano7i stellatim-sidcattim. On Coon Creek, within a 

 mile of the Buffalo River, east of the home of William Goodwin, 

 the Brownsport section is 88 feet thick. It is overlaid by the 

 Hardin sandstone, and 78 feet below the top contains ConcJiidhun 

 lindenensis. At the W^ebb or Rise mill the Black shale series is 



