386 DARTON GREEN POND, N. J., TO SKUNNEMUNK MT., N. Y. 



In New Jersey there is a thin mass of shales, above alluded to, which 

 extends along the eastern side of the northern part of Kanouse mountain 

 between the Green Pond conglomerate and the Cambrian limestone, but 

 no fossils have been discovered in them and their age is not definitely 

 established. As they resemble the Hudson shales in appearance and 

 appear to overlie the limestone unconformably in the usual way, and 

 there are no shales of Cambrian age in the region northward, it is |)rob- 

 able that thev are Hudson. 



Cambrian Limestone. — Thegreater part of the Green pond-Skunnemunk 

 basin is underlain by a series of limestones which are an extension of 

 the " magnesian limestones " of northern New Jersey. They are un- 

 conformably overlain by the other formations. 



Along the eastern side of the basin they outcrop for some distance 

 north and south from Greenwood lake, occupy a wide area east and 

 north of Monroe, and are exposed at intervals south and east of Corn- 

 wall Station. To the southwestward they are bared of Hudson shales 



along the western side of Bell- 

 vale mountain, opposite the 

 southern end of Skunnemunk 

 mountain and along the east- 

 ern side of Woodcock hill. 

 They are light colored, mas- 

 sively bedded rocks closely 

 resembling the Calciferous of 

 the Mohawk valley. They 

 present the same characters 

 throughout the belt, and I 

 have no doubt as to the essen- 

 tial identity of the beds in the 

 several areas represented on plate 17. Their distribution was in greater 

 part shown on the map accompanying the " Geology of New Jersey," 

 1868, but I have found several other exposures and areas. 



These limestones were formerly supposed to be of Lower Silurian age, 

 but in recent years fossils have been discovered in the region west of |;he 

 Highlands by Beecher, Foerste, and others which indicate a Middle 

 Cambrian age for some thickness of the lower members. Last autumn 

 Mr C. D. Walcott* made the very important discovery of Olenellus in the 

 area south of Greenwood lake, and thus definitely established the age 

 of the beds, at least in this portion of the belt. 



In the area south of Greenwood lake the limestone is underlain by a 

 light colored quartzite, in part conglomeratic, which occurs at intervals 



Figure i.— Cross section of the north rn End of Ka- 

 nouse Mountain and the Valley eastward {looking 

 north). 



ilf= Monroe shales; O = Oriskany grit ; HI = 

 Helderberg limestone; L = Lougvvood shales; 

 (2 = Green Pond quartzite; G = Green Pond con- 

 glomerate ; H = Hudson slates ; UC = upper eon- 

 glomerate; C= Cambrian limestone; LC = lowev 

 conglomerate ; A = Archean. 



*A notice of this discovery vvjll appear in the American Journal of Science for April, 1894. 



