﻿432 W. N. Rice — Trap and Sandstone, etc. 



dinary material of the brownish red sandstones, showing no 

 sign of induration or alteration. 



4. A red, shaly sandstone, perfectly normal and unaltered. 



5. Sandstone, brighter red in color, somewhat indurated (but 

 no more so than is frequently the case in places remote from 

 igneous action), so fine grained as to approach in that respect the 

 character of a shale, but not laminated, appearing vesicular 

 where it has been weathered, but having the cavities below the 

 surface filled with calcite. 



6. Fine-grained purplish gray or dove-colored sandstone. 



7. A highly metamorphosed sandstone, greenish gray in 

 color, and so highly crystalline that hand specimens of it would 

 be mistaken for trap. This extreme condition of metamor- 

 phism extends downward two or three feet from the junction 

 with the overlying trap. Calcite in minute particles is dis- 

 seminated through the mass of this metamorphosed rock. 



8. Just at the junction of the sandstone with the overlying 

 trap, a seam about three inches in thickness, decomposed and 

 crumbling, appearing when wet about like a layer of mud. 



9. The overlying trap, for a short distance above the junc- 

 tion, black and almost lusterless. 



10. The black, lustrous, highly crystalline trap of the upper 

 sheet, in its normal character. 



These phenomena seem to lead irresistibly to the conclusion 

 that the lower sheet of trap is contemporaneous. The increas- 

 ingly amygdaloidal character of the trap near its upper surface, 

 the weathered and water-worn pebbles of trap in the lowest 

 layer of the stratified rocks, the perfectly unaltered character 

 of the lower layers of sandstone, so strongly contrasted with the 

 intense metamorphism of the layers near the contact with the 

 overlying trap — all find their explanation in this view. 



If the lower sheet of trap is contemporaneous, it would be a 

 natural conjecture that the upper one is also contemporaneous. 

 On this point, however, I have no positive evidence. I follow- 

 ed the bank of the river down stream till I reached the outcrop 

 of the overlying sandstone, but found no contact visible. The 

 only fact noted which has any significance in relation to the 

 question, is that the trap of the upper sheet changes its char- 

 acter near its upper surface, becoming greenish gray in color 

 and minutely amygdaloidal. Amygdules of calcite about the 

 size of the head of a pin are somewhat abundant. This fact, 

 so far as it goes, is in favor of the conjecture above stated. 



The railroad to Hartford runs along the right bank of the 

 river; and, in following the curves of the river, it passes 

 through two cuttings in the lower or amygdaloidal sheet of 

 trap. In the more northerly of the two cuttings is to be seen 

 a peculiar breccia, forming a nearly vertical band two or three 



