ECONOMICAL GEOLOGY. 



lower Carboniferous series of limestones, sandstones, shales, etc., 

 having thinned out in a northerly direction before reaching the 

 southern borders of that county. 



The Devonian limestone in this county presented an uneven sur- 

 face for the reception of the overlying coal deposits, and conse- 

 quently the coal itself was not found of uniform thickness, being 

 often much thicker in the depressions of the limestone than else- 

 where, and sometimes giving out altogether on the higher portions 

 of the underlying beds. This has made the business of prospecting 

 for coal in this county rather precarious for some years, and led to 

 the expenditure of a considerable amount of capital that has yielded 

 no adequate return. 



But it is clear, as these experiments show, that the main deposit 

 of coal in this county is now well nigh exhausted, and prospectors 

 will do well to turn their attention to the counties lying to the east- 

 ward, where the higher seams may be found. 



For the benefit of those who may not have access to the preceed- 

 ing volumes of these reports, the following condensed section of the 

 Coal Measures of this State is here inserted. 



180 to 200 feet. 



to 90 feet. 



75 to 80 feet. 



20 to 26 feet. 



60 to 70 feet. 



80 to I"" fee!. 



Sandstone and shale with a six inch seam of coal. 



Coal No. 161^ to 3 feet. 



Sandstone and shale. 



Coal No. 15-1 to m feet. 



Sandstone and shale. 



Coal No. 14 1; to 2 feet. 



Sandstone and shale. 



Coal No. 130 to 3 feet. 



Sandstone and shale. 



Coal No. 120 to 1 foot 



Shales and limestone. 



Coal No. 110 to 1 foot. 



Shales. 



Coal No. 100 to 1 foot. 



Sandstone, shales and limestone. 



Coal No. 90 to 2 feet. 



Sandstone, shale and limestone. 



Coal No. 81 to 2 feet. 



Sandstone, shale and limestone. 



Coal No. 71 to 9 feet. 



Sandstone, shale and limestone) 



Coal No. 60 to 6 feet. 



