ciding for several miles very nearly with the course of the 

 Ramapo river; then pursuing, in a gently curving course, the 

 base of the Pompton Mountain, the Trowbridge Mountain, Mine 

 Mountain, and the Musconetcong Mountain, until it meets the 

 Delaware in the vicinity of Durham. 



The average width of the district between the two limits here 

 traced is about twenty miles. Both as respects its geology and 

 its topographical features, this is one of the best characterized 

 belts of country in the State. Most of its surface is a moderately 

 undulating plain, composed almost exclusively of a more or less 

 argillaceous red sandstone. But this plain is diversified by nume- 

 rous abrupt and rugged hills, and long and narrow ridges of no 

 great elevation, but of very steep and rocky sides, consisting of 

 greenstone trap, which impart to the district much pleasing 

 scenery, and lend to its geology and mineralogy some highly 

 curious and interesting peculiarities. 



The second division of this part of the State includes the entire 

 chain of the Highlands, bounded on the southeast by the line 

 already traced along the base of the Ramapo, Pompton, Trow- 

 bridge, and Mine Mountains, Fox Hill east of German Valley, 

 and Musconetcong Mountain, and on the northwest by the north- 

 western base of the ridges known as the Pochuck Mountain, 

 Pimple Hill, Furnace Mountain, Jenny Jump Mountain, Scott's 

 Mountain, and Marble Mountain at the Delaware. 



The belt of hills embraced within the limits here delineated is 

 widest towards New York, their breadth at the state line being 

 about twenty-three miles ; while a transverse section through 

 Scott's and Musconetcong Mountains near the Delaware will 

 not exceed nine miles. 



Though possessing only a moderate elevation, which rarely 

 exceeds six hundred feet, measured from the adjacent valleys, 

 they are distinguished by their mountainous aspect, their sides 

 being usually very rugged and steep, their outlines boldly undu- 

 lating, and their surface for the most part clothed with forest. 

 The whole group consists of a series of parallel ridges, composed, 

 with the exception of a single range — the Green Pond Mountain — 

 of thickly bedded stratified primary rochs ; the prevailing direc- 

 tion, both of the strata and the ridges which they form, being 

 about northeast by north and southwest by south. Included 

 between these ridges occur several long, narrow, and parallel 



