1892.] NEW YORK ACADEMY OF SCIENCES. 137 



Professor Merrill proposed the following classification for this 

 series of rocks : — 



"Gravw-iokPslatP f Bearfort and Schunemunk •] 



Ura} wacke-slate. | mountains, 700 ft. [„ ..^ 



Blue Argillite and f Longwood and West Milford ' tiarailton. 



Graywacke. \ valleys. 1000 " J 



1 . ^' J 0-" Newfoundland, Upper Long- f Corniferous. 



glomerate and Si- -^ j j t>- i :• ea i^ i v^v^|""ciuua. 



Hceous Grit. 1 wood, and Pickatinny. 50"rOnskany. 



Blue Limestone with j Upper Longwood, Milton, New- "t Lower Helde- 



Fossils. (. foundland, etc. 200 " J berg. 



Red Shale. Newfoundland, etc. 200 " Medina. 



Red Conglomerate Green Pond mountain, etc. 600 " Oneida. 



2750 ft."i 

 In the graywacke slates at Clinton Falls, about one and one-half 

 miles N.N.W. of Newfoundland, N. J., Professor Merrill states 

 that " there seem to be traces of plant impressions in them, and 

 they may correspond to the beds in Orange county, New York, 

 which have yielded PsUophyton princeps, and other Devonian 

 plants; that they are of Devonian age is beyond question.'" 



The " Geological Map of New York City and Vicinity, by D. 

 S. Martin, 1888," gives the region of Green Pond and Bearfort 

 mountains, New Jersey, as belonging to the Upper Silurian and 

 Devonian periods. In the " Legend" the green color is stated to 

 represent the Upper Silurian, the " Green Pond Mountain forma- 

 tion," which is given in parentheses as of Oneida and Medina age. 

 The green color is spread over the Green Pond, Copperas, Kanouse, 

 and Bearfort mountains ; while in the valleys partly between these 

 mountains is the brown color which represents the Devonian and is 

 explained as " Slates, Hamilton in part (mingled with Ordovician 

 B.)." The division B. of the Ordovician is given in the legend as 

 " Slates and shales (Hudson River)." In the explanation of this 

 map Professor Martin states, "It is now known that the ' Green 

 Pond Mountain' series, long supposed to be of Potsdam age, is 

 reall}' at the base of the (upper) Silurian, and represents the Oneida 

 and Medina rocks of New York State, or the Levant (No. 4) of 

 the First Pennsylvania Survey. The heights here are, therefore, 

 * Mountains of Four,' and are colored accordingly. They doubtless 

 rest upon Ordovician beds, which are seen outcropping at a few 

 points on the eastern edge, and forming an island in Greenwood 

 Lake, close to the State line. But the slates and shales of the ad- 

 jacent valleys are the most uncertain ground in the map. They 

 were long called Hudson River, but now are proven to be, at least 

 in part, of Hamilton age. What portions, however, are such, and 

 what may be still regarded as Ordovician, are points that are as 

 yet unknown, and will require careful field-work to determine."* 



' Op. cit., p. 114. 2 Op. cit., p. 119, 



^ Geological Map of New York City and Vicinity, by Daniel S. Martin, Notes 

 and Explanations, p. 4. 

 Vol. XL— 10. 



