Davis — Quarries in the Lava Beds at Meriden. 



a great extrusive lava sheet, once horizontal and continuous ; 

 now tilted, dislocated and denuded. Some of the dislocations 

 of the region are indicated in fig. 1 by oblique dotted lines. 



\ r |SL AND SOUND 



The more local relations of the quarry ridge are exhibited 

 in diagrammatic fashion in fig. 2, looking north. Here a piece 

 of country, stretching from the western crystalline highland 

 across the Triassic sandstones and the trap ridges, to the eastern 

 highland, is roughly figured in perspective ; the front face of 

 the figure showing a vertical section of the faulted Triassic 

 formation unconformably overlying an eroded foundation of 

 crystallines. Much detail is omitted, and as is usual in the 

 construction of generalized diagrams of this kind, a greater 

 degree of definiteness and certainty is given at various points 

 than would be allowed in a verbal statement. The structure 

 of the crystalline rocks is wholly diagrammatic. The draw- 

 ing nevertheless has a value in placing the reader quickly in 

 possession of a number of important structural features. The 



