163 



INDEX, 



A. 



Page. 



Alleghany ridges, description of -^ a - ' - ... - 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 - ',*'- - - ":, t - . - 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 VV - 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 



Geodes at Keokuk, Mississippi >.' 159 



Carver, Captain, remarkable locality mentioned by him - 129 



Cave in sandstone described by him - 135 



River bearing his name ' - ''""" V ' - '' *'''' - 138 



