BULL. GEOL. SOC. AM. 



VOL 16, 1904, PL. 24 



Section through A B. 



MAP OF TRAP SHEET ACROSS HOLYOKE AND SECTION 

 Scale : 1 mile to the inch 



Plumose 



Diabase 



and 



Pa I aconite . 



Band of 

 Steam holes 

 in diabase. 



Surface 

 band of 



mud 

 enclosures. 



HolyoKe 

 Diabase 

 Sheet 



T 



Triassic 

 Sandstone. 



