Triassic Fault of Southern Connecticut. 



493 



Location 



Depth 

 in feet 



Near Northampton.. 3.700 

 Winchester Arms Co. 



New Haven 4,000 



Near Cheshire, about 4,000 



Distance from crys- 

 tallines to west in 

 miles 



not over 2 or 3 



about 2 

 about 1-1/2 



Distance expressed 

 as a fraction of 

 that from the 

 crystallines on 

 west to the out- 

 crop of the lower 

 sheet 



not over 1/2 



about 1/3 

 less than 1/2 



None of these wells penetrated the crystallines. In 

 view of these facts the thickness of the lower sandstones 

 may be estimated at 8,000 feet or more. Their thickness 

 in the Pomperaug Valley, about 15 miles to the west, is 

 only 1,200 feet, which may indicate that they thicken to 

 the east. 



The accompanying fig. 5 shows the various elements 

 which enter into the estimation of the throw of the fault. 

 The throw is the sum of the following values : 



The thickness of the lower sandstones 8,000 feet or more 



The thickness of the remainder of the Triassic 



now remaining 5,500 feet or more 



( The sum of these two is shown as HK on the 

 diagram. The movement along the fault 

 plane was AB ) . 

 The thickness of possible Triassic sediments 

 above the highest beds now exposed (Move- 

 ment BC, Throw KL) Unknown 



Thickness of upraised block worn down dur- 

 ing Triassic to provide sediments for the 

 Triassic strata (Movement CD, Throw MD) Probably at least 



several thousand 

 feet; may have 

 been greater 

 than, the whole 

 thickness of the 

 Triassic. 



Post-Triassic Faulting 



(Movement DE, Throw PE) 



The tilting of the sediments; 

 the apparent appearance of 

 lower and lower horizons of 

 the metamorphic rocks in 

 going west towards Derby; 

 and the great shattering of 

 the highest Triassic horizons 

 exposed indicate that this was 

 great. 



