The Trap Ridges of Meriden Again 



By J. H. Chapin, Ph. D. 



A protracted absence from the country, on a tour round the 

 world, since the issue of the last volume of these Proceedings, has 

 interfered with the exploration of the Trap dikes or ridges we had 

 intended to make, and we have little therefore that is new to add 

 to what has been said before. 



Prof. W. M. Davis of Harvard University however, has vigor- 

 ously prosecuted his explorations from time to time, and with his 

 classes in the Summer School of Geology, has passed over por- 

 tions of the region about Meriden repeatedly. His conclusions go 

 far to strengthen and confirm the theory, that the whole area now 

 occupied by the Trap ridges, was once covered by a contin- 

 uous sheet of igneous rock, the result of one or more overflows ; 

 and that the separation of the ridges by intervening valleys or 

 ravines, as at Cathole Pass, the Reservoir Notch, and the more 

 considerable depression west of Lamentation Mountain was due to 

 the rupture of the overlying sheet and faulting of the rocks. Prof 

 Davis speak for himself, however, in an article on another page. 



Tlie feature of more special interest at present is the evidf^nce, 

 of profound volcanic disturbance of the region named, in the bed 

 of ashes and bombs of unmistakable origin, which stand out so 

 prominently on the west slope of Mt. Lamentation — or speaking 

 more precisely — in the Anterior ridge of Trap adjacent to Mt. 

 Lamentation and near the road from Meriden through the Berlin 

 Woods. The line of ash has been traced in a south-easterly direc- 

 tion and appears at different points along the range of ridges, 

 leaving the observer quite in doubt as to the precise point of its 

 origin. Whether there was one long rupture from which the ashes 

 appeared, or a single crater of more pronounced volcanic char- 

 acter, or more than one volcanic vent along the flanks of these 



