Ransom ii. I 



Eruptive Rocks of Point Bonita. 



97 



Figure io. — Section of diabase, showing rounded crystals of iddingsite, and 

 intergrowths of augite and hornblende, a, augite ; BH, brown 

 hornblende ; GH, green hornblende ; p, plagioclase ; s, idding- 

 site. X 21. 



