EVIDENCES OF FAULTIXG. 525 



cause less alteration than movement transverse to it. It would be more 

 difficult also to demonstrate that the change was due to faulting, because 

 any change that occurs might be attributed to a change in the character 

 of successive folia across the strike rather than to a change in a single 

 relatively continuous portion of the crj^stalline mass along the strike. 



Association of marginal and internal Faults. — The internal faults, as 

 those which are found within the Triassic area may be called, have been 

 successfully worked out along the trap belts, whose numerous disloca- 

 tions give complete demonstration of their occurrence. In the district 

 about. Meriden there are two chief faults — one separating Higby moun- 

 tain from Chauncey peak, the other separating Lamentation mountain 

 from the ridges of the Hanging hills. The throw of these faults is esti- 

 mated at 2,000 and 3,000 feet respectively. Their course is about north- 

 east and southwest, though the latter fault splits near Berlin ; one branch, 

 having a throw of 1 ,000 feet extends northeastward, the other branch turn- 

 ing to the north. After their discovery by means of the dislocations in 

 the trap ridges, they were traced in both directions by means of the local 

 deformation that they caused here and there in the bedded rocks, and 

 they have now been extended with some confidence to the crystalline 

 areas both northeast and southwest of the locality in which the}^ were 

 first detected, by means of dislocations and breccias along their lines. 

 It is therefore regarded as a matter of much significance that the oblique 

 courses of the eastern border, determined by the second and the fourth 

 faults of the marginal series, fall directly in line with the northeast ex- 

 tension of these two great internal faults. The essential accordance of 

 these members of the internal and external faults, although unlike in 

 appearance and of independent discovery, but both explicable as common 

 effects of a single kind of process, leads to much confidence in our con- 

 clusions. 



Additional Evidence from the separate Fardts. — The general evidence 

 above stated is sufficient to desnonstratc faulting along part of the con- 

 tact for the two formations in question ; still, more evidence is desirable, 

 and to get any quantitative idea of the faults, is necessary. 



Fault nuini)er 1 is bordered by a part of the Triassic area which has 

 been warped into three shallow, saucer-like folds. Their diameters are 

 five, seven and fifteen miles respectively, beginning at the south ; these 

 may be called the Pond, Totoket and Middletown saucers ; but these 

 saucers are not complete, only their western halves are visible. About 

 one-half of what must have been their original area, had they been s^mi- 

 metrical, would belong east of the border line where we now find the 

 gneisses and schists. Thus what may be termed the broken edges of 

 the saucers abut against the contact line, presenting the Triassic rocks 

 with strikes varying from parallel with the contact line near the middles 



