163 



INDEX 



A. 



Page. 



Alleghany ridges, description of 103 



Origin of - 108 



Extend to the great bituminous coal field of the West - 109 



Alps, western, upheaved since the tertiary beds were deposited - 67 



Anthracite coal 43 



Slightly bituminous - - .44 



At Seneca creek, Potomac - - 97 



Between Sleepy-creek mountain and Third hill, Virginia - 102 



Its geological position distinct from that of the bituminous - 113 



Atlantic primary chain - - 37 



On the Boonsborough road, Maryland - 99 



Its origin - - - - 100 



B. 



Boulders, primary - - - - . - 117 



Remarkable locality of - 141 



Breccia, calcareous - - - - - 98 



Masses of, near Frederick, Maryland - 100 



Siliceous, in Fauquier, Virginia - - 100 



C. 



Cambrian system of Sedgwick - - 32 



Canal, Chesapeake and Ohio - 95 



Carboniferous limestone - .45 



Identified by fossils - 48 



Oolitic beds of, in the United States - 54 



At Sandusky, Ohio - - 117 



At Green bay - 119 



At lower Fox river - 121 



- 



In concentric masses - - 134 



At Fort Snelling - - - * . 135 



Uninterrupted continuation of, for 1000 miles - 137 



Contains silicate of iron in seams - - 140 



Geocles at Keokuk, Mississippi - 159 



Carver, Captain, remarkable locality mentioned by him - 129 



Cave in sandstone described by him - 135 



River bearing his name - - 138 



