TRIASSIC PERIOD. 



431 



these crystalline rocks, underneath the sandstone. Even the little 

 Southbury Triassic region has its trap, and it has the same direction 

 as in the Connecticut valley. 

 The trap usually forms hills with a bold columnar front and 



Fig. 651. 



Map of part of the region in central Connecticut between New Haven on the south and 

 Windsor on the north, showing the trap dikes which intersect the region; a, b, c, d, e, 

 course of western boundary of Triassic, beyond which the rocks are metamorphic. 



