336 ANNALS NEW YORK ACADEMY OF SCIENCES 



J. Volney Lewis, The Correlation of the Newark (Triassic) Trap 



Rocks of New Jersey. 



Henry B. Kiiminel, Recent Investigations of the Potable Water Sup- 

 plies OF New Jersey. 



H. S. Washington, Some Volcanoes of the Western Mediterranean. 



Ida H. Ogilvie, A Contribution to the Geology of Maine. (By 



title.) 



J. F. Kemp and 



J. 6. Ross, A Peridotite Dike in Coal Measures of South- 



western Pennsylvania. 



Summary of Papers. 



Professor Lewis said that the disconnected extrusive traps west of the 

 Watchung Mountains may be explained in several ways, but they are prob- 

 ably the results of scant eruptions, the New Vernon crescent being the 

 upturned western edge of the Long Hill trap. The extrusives at Sand Brook 

 and New Germantown are probably outlying remnants of, or at least con- 

 temporaneous with, the flows of First and Second Mountains. 



Darton's dike-and-sheet h}'pothesis of the Palisades sill is not supported 

 by the facts, the trap being roughly conformable to the strata, as far as 

 knoAVTi, in all directions. The chance of the fissure of intrusion coinciding 

 with the western flank of the Palisades from Weehawken to Haverstraw 

 is exceedingly small. On the other hand, data now available quite satis- 

 factorily establish the connection between the Palisades and the trap of 

 Rocky Hill to the southwest, and a section along the Delaware River shows 

 a threefold repetition of this by faulting. Thus there is but one intrusive 

 sheet, which gives off numerous dikes and apophyses, in contrast with four 

 extrusives, Second Mountain being double. 



The intrusive is considered of later age than the first extrusive, and may 

 be contemporaneous with one of the later extrusives or subsequent to all of 

 them. This conclusion is in harmony with the results of recent studies of 

 the copper deposits, which are intimately connected with the intrusion of the 

 great Palisades sill. 



There are many points of resemblance to the Connecticut Valley traps: 

 the same number of extrusives appear in both, grouped in the uppermost 

 strata; in both the second is a double flow; an intrusive sill lies near the 

 base, and dikes cut the intervening strata. 



The paper was discussed by Messrs. Kemp, Britton, Kiimmel, Tuttle, 

 Grabau and Hovey. 



Dr. Washington described briefly the volcanoes of Catalonia, Sardinia, 



