Feather stonhangh^s Geological Report. 47 



Although there is a true succession of the beds just enume- 

 rated in this group, yet it by no means occurs that the mem- 

 bers of the group are all found in the countries where the 

 formations even exist. In some instances many of the beds 

 are entirely deficient, and in numerous cases they are ex- 

 tremely thick, whilst in others scarce a trace of them ap- 

 pears even to have been deposited. In some countries the 

 coal measures are entirely distinct from the millstone grit 

 and shale, and carboniferous limestone, whilst in others they 

 are almost blended together by alternations of sandstones, 

 limestones, and shales. In the State of Maryland, pursuing 

 the road from Hancock to Frostburg, near Cumberland, the 

 carboniferous limestone does not develop itself, as in the 

 Western country, in extensive horizontal areas. On leaving 

 the highly-inclined Silurian rocks, red shales and sandstones 

 succeed to each other. At Flintstone there are beds of lime- 

 stone containing abundance of organic remains having a strong 

 affinity to those of the carboniferous limestone, but to these im- 

 mediately succeed alternating sandstones, shales, and slaty 

 limestones ; and thus the country rises from Cumberland to 

 Frostburg, about 1 ,300 feet, where is one of the richest and most 

 regular developments of the coal measures in the United States, 

 with little indication, except what is gathered from fossils, of that 

 carboniferous limestone which has such a splendid extension in 

 various parts of the Western country, and through which the Mis- 

 sissippi flows more than a thousand miles.* It is the very reverse 

 of the picture which the same formations present on descending 

 the country from the Cumberland mountains, by the way of Spar- 

 ta, to Nashville, in Tennessee. At the summit of those moun- 

 tains, the sandstone contains nothing more than indications of 

 bituminouscoal, whilst, on descending, the carboniferous lime- 

 stone immediately develops itself, in great force, to a depth of 

 eight hundred feet, to where the Cumberland river loses 



* This is the preponderating formation in Ireland. 



