Merrill — Metamorphic Strata of S. E, New York. 



In each case it appears that geological work went forward as 

 long as subsidence was continued ; and that stoppage of bud- 

 Bidence was Btoppage of work^ in accordance with a general 



•logical law. Some would put it— Stoppage <>t" work of 

 deposition was genetically stoppage of subsidence; but the 

 question is not yet so settled, Moreover, the deposits in cadi 

 trough were thickest along some axial line in the trough, or 

 more than one, where its subsidence was greatest. 



The facts illustrate strikingly the great truth that the earth's 



features even to many minor details were defined in Areluean 

 time, and consequently that Archaean conditions exercised a 

 special and even detailed control over future continental 

 wth. The extension of North America to the most eastern 

 point oi Newfoundland, and beyond it, was determined in this 

 beginning time; and likewise, that of the European Continent 

 to the Hebrides, in front of the Scandinavian Archaean area. 



Art. XL VIII. — On the Metamorphic Strata of Southeastern 

 New York; by Frederick J. II. Merrill. 



Of the strata comprised in the metamorphic terrane of 

 southeastern Xew York there are two principal divisions. 



First, in Rockland, Orange, Putnam and Dutchess counties, 

 the granitoid gneisses and granulites of the Highlands, which, 

 with their continuation in New Jersey, can be shown strati- 

 graphically to be pre-Cambrian, since they underlie unconform- 

 able in southern Dutchess County, X. Y., and at several points 

 in New Jersey, a basal Paleozoic quartzite of Potsdam or 

 Lower < Cambrian age. 



londly, in Westchester and New York Counties the gneis- 

 soid quartzites and arkoses overlain by crystalline limestones and 

 mica schists, which border the rocks of the first division on the 

 southeast and have been regarded as altered Paleozoic rocks of 

 Ordoviciau or Cambrian ace by Professors W. W. Mather and 

 .1. I>. Dana. 



The metamorphic rocks of the Xew Jersey Highlands were 



first definitely classified by Dr. X. L. Britton as a result of his 



Studies in L885 and L886.* In this terrain' he identified three 



ips : first; a Massive Group, devoid of bedding planes, 



talline. The facts are of interest here; for the troughs are all parallel to the 

 9 of the Appalachian Mountains, curving with all t heir long curves; and 

 at the same time, as is true also for the Nova Scotia and Connecticut valley ar 

 the deep subsidence went forward in each — 3000 to 5000 feet — without giving 

 access to Bait-water. The troughs were kept filled with Bediments. 

 * Annual Report Geol. Survey of N'ew Jersey, 1 985-1686. 



