108 Association of American Geologists and Naturalists. 



Second. — Subsequent to the accumulation and consolidation of the 

 sedimentary rocks, and resulting by known physical laws from this ac- 

 cumulation, a transfer of focal energy in the internal heat was effected, 

 which resulted in the disruption of the lower primary rocks, in the form- 

 ation of long parallel dykes of trap in them, which discharged their 

 molten contents among the sedimentary strata, distributing it among 

 them along the lines of least resistance, up the plain of the dip, eleva- 

 ting the superincumbent strata parallel to the dip from the beds on which 

 they before reposed, and producing in the superior strata fissures and 

 transverse cracks toward the extremity of the sloping dyke, which were 

 of course filled with molten trap. This injection was probably continu- 

 ed during a long period, but is all referable to the same geological epoch, 

 and anterior to the elevation of the strata in which it occurred ; and 

 probably few of the dykes reached a point so elevated as the then bottom 

 of the ocean. 



Third. — After the period of deposition and injection ceased, and the 

 elevation of the present continent had commenced, there occurred enor- 

 mous denudation by a northerly current, whose records are every where 

 found on the rocks in place, and in the loose detritus of rounded and 

 transported drift which every where covers the valleys of this and ad- 

 jacent regions. This current was probably due to the flowing off" of the 

 oceanic waters on the elevation of the present continent. By this de- 

 nudation the softer shales, and even harder conglomei'ates, were remov- 

 ed, and the previously formed trap ranges were fully developed ; many 

 were removed entirely ; the only record we have of them being in the 

 long parallel dykes in the adjacent primary and their ruins among the 

 diluvial materials of Long Island. This point involves the necessity of 

 supposing the secondary once to have had an extension so great as to 

 cover most of the now prominent trap ranges of the Connecticut valley, 

 and that portion of the adjacent primary included between the South- 

 bury basin on the west and the trap dykes of the eastern primary. 



It was also inferred that the geological age of this region is satisfac- 

 torily determined to be the period <^ the new red sandstone. 



This paper was illustrated by a large colored copy of Dr. Percival's 

 outline map of Connecticut, by two ideal sections in support of the views 

 submitted, and by a picturesque view of the Hanging Hills of Meriden, 

 a well marked instance of the physical character of the trap and red 

 sandstone formation of Connecticut. 



Prof. Hitchcock remarked that his views on the question of 

 the elevation of the sandstone, and on the origin of the materials 

 composing it, were different from those expressed by Mr. S. in 

 his paper. 



