80 Geological Survey of the State of New York. 



so in New York, and extends, in an almost unbroken range, from 

 the New Jersey line, on the top of the Shawangunk mountain, 

 to Rosendale, near Kingston, a distance of forty three miles, where 

 it disappears beneath the water limestone and tertiary deposits of 

 the Hudson valley. On the higher parts of the Shawangunk 

 mountain, it generally lies in nearly horizontal strata, often thick 

 bedded, and in mural escarpments, of broken ends of the strata, 

 thirty to two hundred feet high ; on the eastern face of the moun- 

 tain the strata have a high dip to the east southeast, and on the 

 western side the dip is almost uniformly to the west northwest and 

 northwest, in some places from 30° to 60°. Two systems of 

 fractures, more or less coincident with and transverse to the direc- 

 tion, are found ; and where the elevatory movement has been 

 along the latter, the dip is N. N. E. or S. S. W ; where the up- 

 heave has been longitudinal, the dip is W. N. W, or E. S. E. 

 The same general principles hold true in the rocks lying lower in 

 the series, as the Hudson slate group, and the rocks of the High- 

 lands. Most of the streams follow these lines of fracture, chang- 

 ing from one to the other, to produce many of their changes of 

 direction. Some of these lines of fault have been traced for 

 many miles across mountains and valleys. 



" In the rocks thus described, there is evidence of at least three 

 elevatory movements, viz. one (at least) before the deposition of 

 the Shawangunk grit strata ; another after the deposition of this 

 and the Helderberg and Catskill series, and before the tertiary 

 epoch ; and another since that period. The Hudson slate group 

 consists of a series of slates, shales, grits and limestones, with si- 

 licious and calcareous breccias, and hypogene and Plutonic rocks, 

 which correspond in many respects with the ''Cambrian system" 

 of Prof Sedgwick, and occupies most of the country between 

 the Highlands on the southeast and the Shawangunk mountains 

 on the northwest, and forms the mass of the latter mountains be- 

 low the Shawangunk grit. From Kingston, it ranges along the 

 western bank of the Hudson, to Albany, (ninety miles,) under- 

 lying the superincumbent rocks, unconformably with few ex- 

 ceptions. Its range on the left bank of the Hudson, as far as ex- 

 amined, is detailed in the second annual report. Its fossils, ob- 

 served this year, are a few impressions of shells,"and some Fucoides, 

 or Graptolites, from the black shale below the Shawangunk grit, 

 from 500 to 700 feet above the valley." 



