TACONIC SYSTEM. 
437 
gneiss at the base of Mount Stessing, and is overlaid by the Barnegate limestone, and that 
by the slate rocks of the west side of the mountain. It resembles gneiss at a little distance, 
but is a hard, close-grained, siliceous grit rock. Another mass of this rock was mentioned 
by Mr. Walter Reynolds of Pineplains, and said to cross the limestone ridge obliquely, a short 
distance southeast of Pineplains. 
The ridge dividing Washington and Pleasant-valley has breccia and sparry limestone on 
its western base, and red slate a little farther to the west, and ranges south into Lagrange. 
Talcy slate was also observed by Prof. Merrick a little east of Verbank in Unionvale, and he 
considers it as being an extension of that observed in the southeast corner of Stanford ; also 
sparry limestone half a mile east of Mabbitsville, and talcy slate two and a half miles east of 
the same village. 
The slate in the ridges passing through the eastern part of Stanford, the middle and western 
parts of Washington, and along the line between Unionvale and Lagrange, is very much 
traversed and intersected by viens of quartz, and is contorted. The outcropping edges are 
waving. Extensive excavations are said to have been made in these rocks in the northeast 
part of Lagrange, about sixty years ago, in search of silver; and although there are marvel¬ 
lous reports of the quantities obtained, no traces of any metal were observed but pyrites. 
Talcy limestone was observed in place about a quarter of a mile west of Hopewell. 
Wliite limestone, thatwould make a good marble, was seen about one mile west of Poughquaick. 
Limestone is the most common rock seen emerging ' through the extensive quaternary plains 
of Fishkill, and in many places it assumes the aspect of what we have been in the habit of 
calling primitive limestone ; but which is the same as that generally found in this valley, and 
which has now been traced in modified forms, from a compact and sandy limestone to a white 
marble, from Vermont to the Highlands. 
About one mile and a half above Matteawan in Fishkill, near the creek, the limestone seemed 
to repose on the granite rock. The limestone was on the east side of the granite, dipping to the 
east; and the granite was succeeded on the west by red and green slates, that seemed to pitch 
under it towards the east. The direction of the granite and associated rocks was parallel to 
the creek for some distance, forming a low ridge, which finally crosses the stream about a 
quarter of a mile from the bridge. The strike is N. 50° E. The red and green slates are 
red and green in the same continuous layers, and the colors are probably due to the different 
degrees of oxidation of iron in the different parts of the rock. Near Matteawan, also, the 
granite, and red, green and black slates were observed. 
About one mile east of Stormville in Fishkill, the limestone of the Fishkill valley is succeeded 
by the granite and gneissoid rocks of the Highlands. Patches of limestone, however, like 
that of the valley, were occasionally seen on the mountains farther east. The dip of these 
primary rocks was 60° to 80° eastwardly, and the strike N. 45° to 60° E. 
Altered slate rocks, that may be classed with the Taconrc rocks, occur about four miles 
north of Newburgh, near a small hill of granite rock. 
The limestone of Monroe, between the Highlands and Goosepond mountain, and about Belle- 
vale and Warwick, may also be considered as belonging to the Taconic rocks, as they do in 
