The Hanging Hills. 



By I. H. Chapin, Fh. D. 



A fresh interest attaches to the Hanging Hills — the trap ridges 

 lying just out of the city limits in Meriden, toward the west — 

 in the discussion now attracting attention in regard to their origin, 

 or rather the mode of their occurrence. 



In the Triassic, or Red-sandstone region of the Connecticut 

 valley — extending from the northern limits of Massachusetts to 

 Long Island Sound — are numerous ridges of a dark colored erup- 

 tive rock, somewhat indefinitely described as trap, that have some- 

 time in the past history of this region been pushed up through 

 rifts in the red sandstone for which the section is so well-known. 



No one passing through Meriden, even on the railroad, can 

 fail to observe them, so prominent and striking a feature are 

 they of the landscape. 



And indeed in going from New Haven to Greenfield, Mass., 

 from one to half a dozen of these singular prominences are always 

 in sight. 



Though seemingly disposed at irregular intervals, the map 

 shows that they form a continuous series, not unlike a mountain 

 chain, and suggest at once the presence of some of the forces that 

 from time to time have thrown the earth's surface into rugged 

 folds. But a casual examination is sufficient to show that the ac- 

 tion here was different from that in ordinary mountain making. 



The black rock mass is no part of the original strata laid 

 down in seas or rivers, but an intruder, that found its way 

 hither after the Triassic formation had been deposited, and for 

 which the strata had been rudely disturbed and torn asunder. 



The term Triassic is here used, as the reader will understand, 

 to include the Jurassic also, or so much of it as may be repre- 

 sented along the the eastern border of the continent. Perhaps 

 Tria-Jurassic, or as Le Conte puts it, Jura-Triassic, would be more 

 appropriate. 



