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 tiie 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 lOOO miles - - 137 



Contains silicate of iron in seams - - - . 140 



Geodes at Keokuk, Mississippi - - - - 159 



Carver, Captain, remarkable locality mentioned by him - - 129 



Cave in sandstone described by him . . - 135 



River bearing his name . . - . , 138 



