Williams — Contact-metamorphism near PeeksMll. 255 



Series," which here consist of mica-diorite or mica-hornblende- 

 diorite. No exposure could display more favorably than this 

 one the contact-phenomena between the massive rock and 

 adjacent schists. 



This small area is represented on Professor Dana's map,* but 

 it is here reproduced on a much larger scale from the manu- 

 script chart in the office of the U. S. Coast and Geodetic Sur- 

 vey in Washington. The particular points designated by let- 



Map of the region near Cruger's Station. 



ters are the same as those used by Professor Dana.* They 

 represent three different sections across the schists, one 300-400 

 yards (Z-ra); one 700 yards {o-p); and are 900 yards (q-s) west of 

 Cruger's Station, and are as good as any that could be selected. 

 The mica schists of this area adjoin conformably the small 

 limestone area at Cruger's Station and have an average strike 

 1ST. 70° E. and dip 75° N. ; i. e. they strike nearly parallel to 

 the river bank and dip toward the massive rocks. On the 

 shore they are highly crystalline, but not much crumpled or 

 metamorphosed. As we follow them, however, across the 

 strike they become more and more puckered and tilled with 

 lenses or eyes of quartz containing garnet and other contact 

 minerals. In the schists themselves are developed staurolite, 

 sillimanite, cyanite and garnet. The intensity of the meta- 

 morphic changes is directly proportional to the nearness of the 



* This Journal, III, xx, p. 195, Sept., 1880. 



