TABLE OF CONTENTS. 
Page. 
Description and localities of red rocks. 354 
(2) . Shawangunk grit and conglomerate. 355 
Description, origin of name. 355 
Range, position, dip, thickness. 356 
Topographical features...356 
Systems of fracture; axes of elevation. 356 
Wrinkles, faults. 356 
Hudson and Shawangunk axes. 357 
Uses of the grits: millstones, glass, etc. 357 
Remarks on the materials used in construction. 358 
Metalliferous veins and traditions. 358 
Ellenville lead mine. 358 
Ulster lead mine. 359 
Shawangunk lead mine. 359 
Pyritous grit. 362 
(3) . Rock similar in character to the Shawangunk grit and the interstratified and over- 
lying red rocks. 362 
In Orange county, range and extent. 362 
In counties east of the Hudson. 362 
Age of these rocks attempted to be determined. 362, 365 
5. Champlain division ... 366 
General remarks . 366 
Range. 366 
Subdivisions: 1. Hudson-river group. 367 
2. Utica slate. 367 
3. Trenton limestone.•. 367 
4. Black-river limestone. 367 
5. Calciferous group. 367 
6. Potsdam sandstone. 367 
Synonims of the above subdivisions . 367 
Derangements of all these through Hudson valley. 368 
Extent of axis of disturbance. 368 
General description of these rocks. 368 
Topographical and agricultural characters. 368 
1. Hudson-river group . 369 
Synonims. 369 
General description. 369 
Palteontological characters. 369 
Thickness. 369 
Localities where rocks are well exposed. 369 
Range and extent of these rocks on right bank of the Hudson. 370 
West of the Hudson. Local details in Orange county. 370 
