20 



OUTLINES OF GEOLOGY. 



Creeks, under the name of Shawangunk. It assumes in 

 Pennsylvania the name of the Blue Mountain, and spreads 

 out into a vast number of confused ridges, which have the 

 aspect of a table land cut by deep water courses. The most 

 elevated parts go under the name of Sideling Hill. In Vir- 

 ginia the Cacapon seems to belong to this range, and the 

 confused groups are traced into Georgia. The great 

 Alleghany range seems to take its rise in Hamilton county, 

 New-York. It is thence traced across the Mohawk, which 

 forces its way through it at the Little Falls. About twenty 

 miles south of the Mohawk it turns suddenly to the east, and 

 coming within sight of the Hudson, forms an angle in the 

 Pine Orchard, where it changes its direction to the south- 

 west, and presents an imposing appearance under the name 

 of the Catskills. Following the same direction it enters 

 Pennsylvania under the name of Moosick, and shortly after- 

 wards is first called Alleghany. In Maryland it is known 

 as the Back Bone, and again in Virginia as Alleghany. It 

 may also be traced into Georgia. The remaining two 

 ridges need not be described ; their most northern and west- 

 ern limit in the state of New- York is at the southern end of 

 Canandaigua Lake. The system turns to the westward in the 

 state of Georgia, but which of the ridges in particular are 

 produced is not well ascertained. We have no defined ac- 

 count of the direction of the ranges in Caraccas, Guiana and 

 Brazil, but there is a remarkable similarity, in geological 

 character, between those of the latter country which are most 

 accessible and the outer range of the Apalachian group. 



