176 Forty- SIXTH Report on the State Museum, 



Description of the Geological Map Accompanying the Reporp 



OF Dr. E. Emmons. 



" This map is a reprint, in the main, of the map which accom- 

 panies the first reports. Important additions, however, have been 

 made to it. Parts of Vermont, Massachusetts and Connecticut 

 are now included. In addition to these the range of the Taconic 

 system is colored and made a distinct part of the map. It occu- 

 pies a belt extending from the Canada line to I^ew Jerse}'' and 

 Tappan bay on the ISTorth river, below the Highlands. This 

 system, it will be observed, is divided or split by the primary of 

 the Highlands ; the older part passing on the east side intersects 

 the Hudson at Peekskill, and the superior portion passes on the 

 west side and leads off into JSTew Jersey, passing through the 

 county of Orange. The primary rocks of Massachusetts, Yer- 

 mont and Connecticut, which lie in a position nearly parallel to 

 the Taconic system, are colored with lake, and the Taconic sys- 

 tem a drab. By this addition the relative positions of the New 

 York, Taconic and Primary systems of New England are indi- 

 cated. "We may see the great primary nucleus of New England 

 as it disappears beneath the oldest sedimentary rock now known, 

 composing the Taconic system, and the disappearance of the 

 latter beneath the New York system. The New York system 

 continues the superior system until we reach Green bay and the 

 sources of the Menomone river, where the Taconic system once 

 more appears, supporting the lower members of the New York 

 system, and reposing on, and supported b}^ the Primary, as in 

 Massachusetts, Connecticut and Vermont. 



" The narrow belt of the Taconic system is a remarkable fea- 

 ture in the geology of this country, it being an immensely thick 

 series, which seems to have been deposited in long and remark- 

 ably deep seas that resembled profound clefts in the crust of the 

 earth." 



" The different members are not distinguished by colors ; the 

 difficulty of locating them with that degree of precision which 

 is required in a map, was considered a sufficient reason for omis- 

 sion. The oldest or inferior member, the gray sandstone or 

 granular quartz, lies upon the primary in the range of Williams- 

 town and Dal ton, Massachusetts, and Arlington, Vermont. The 

 Stockbridge limestone forms a belt immediately west, and then 



