THE 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. I. — The Quarries in the Lava Beds at Meriden, Conn. / 

 by William M. Davis. 



Summary. — Three quarries in the Triassic (^Newark) formation 

 near Meriden, showing the vesicular upper surface of one 

 lava bed under the dense basal portion of a later flow, and 

 a number of fractures dislocating the double flow. Rela- 

 tion of these features to the geological structure of the 

 district. 



The present condition of the quarries in the trap ridge near 

 Meriden, Conn., affords so fine an exhibition of the two lava 

 beds of which the ridge is composed and of the fractures by 

 which the beds are faulted, that the following account of their 

 local and general relations is here placed on record. 



The general location of the quarry ridge is a mile north of 

 Meriden, at the point marked Q in the adjoining sketch map 

 (fig. 1) of central Connecticut; broken lines indicating the 

 boundary of the Triassic formation against the crystalline 

 highlands on the east and west. It thus appears that the 

 quarry ridge is topographically the smallest eastern member of 

 the Hanging Hills group and therefore belongs to the long 

 series of ridges that extends from Salton stall or Pond ridge, 

 close to Long Island sound east of New Haven, northward 

 into Massachusetts as far as Mts. Tom and Holyoke. The 

 interpretation of the structure of the district here advocated 

 shows, further, that all these ridges are the outcropping edges of 



Am. Joue. Sci— Fourth Series, Vol. I, No. 1 —January, 1896. 



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