JVuttaWs Geological and Mineralogical Remarks. 241 



brown, containing occasionally pebbles of red and brown 

 jasper. The allinity of this grauvvacke with the red sand- 

 stone of Patterson is sufficiently obvious, not only from 

 hand specimens, but from identity of relative situation, for 

 they both underlay the trap. Casts of ammonites at Pat- 

 terson* have been found in the larger pebbles, contiguous 

 with the surface of the red sandstone formation, or near to 

 the point where it enters m/o junction with the porous trap. 

 In the lower portions of this formation, I believe, as yet, 

 no organic remains have been discovered ; and it is notun- 

 frequently, when approaching to a slaty structure and ar- 

 gillaceous consistence, eminently metalliferous, as at Schuy- 

 ler's copper mine, and that now working at Somerville, 

 which presents masses of the ruby oxid, native copper, and 

 minute portions of native silver. 



Contiguous to the western declivity of the Pompton 

 mountains. Judge Kinsey and Doctor Mead found pale 

 green sahlite in abundant masses, connected with a beauti- 

 ful smallish grained white carbonate of lime or marble, 

 contiguous to a formation of diaphanous greenish yellow 

 perfect s.erpentine, traversed, like that of Newburyport, 

 with silky seams of amianthus. 1 Connected apparently 

 with the greenstone formation, is a large rolled or rounded 

 mass of Labrador felspar, sparingly mixed with hornblende, 

 found by Judge Kinsey in the vicinity of the hills of Pomp- 

 ton. 



After passing the Pompton mountains, a succession of the 

 ridges of the Highlands present themselves, thickly strew- 

 ed with rounded debris, so as to render even the valley 

 lands difficult to cultivate. Passing the Warwick ridge, or 

 Hamburgh mountains, we enter upon the valley of Sparta, 

 where a white crystalline limestone and marble appear, oc- 

 cupying the valley, and rising westwardly into a low subsi- 

 diary ridge, about eight or nine miles in length, proceeding 

 almost due north and south. 



As the metalliferous deposites form here the most re- 

 markable feature of the formation, we shall preface our 

 examination of the minerals of Sparta, by a few remarks 



* Collected by Judge Kinsey. 



t The same mineral, with its usual associate, has been received from 

 Philipstown, on the Hudson, by Professor Renwick, of Columbia College. 



