152 A. Wandke — Intrusive Rocks of 



Volumetric composition of the four phases of the Cape 

 Neddick gabbro : 



I II III IV 



Olivine 17.89 1.5.0 6.76 



Plagioclase 45.50 45.60 51.85 87.10 



Alkaline feldspar 1.17 .... .16 



Pyroxene 23.53 25.00 8.23 9.43 



Hornblende .... 10.01 21.42 .68 



Biotite 3.77 3.26 4.76 1.21 



Hypersthene 2.33 



Magnetite .. 3.62 13.82 6.79 1.55 



Apatite . 2.97 .... 



Totals . . . , 100.78 99.19 99.81 100.13 



I. Contact phase of the gabbro. 



II. Pyroxene-rich phase. 



III. Hornblende-rich phase. 



IV. Central feldspathic phase. 



Agamenticus Complex, 



This complex, so-called to signify that it consists of 

 more than one kind of rock, is situated in York County, 

 Maine, and has been named from Mount Agamenticus 

 upon whose slopes three of the dominant rock types are 

 to be found. 



Biotite Granite. — This rock forms the dominant phase 

 of the batholith. The texture and composition vary from 

 place to place, but on the whole the rock is light colored, 

 has a slightly cataclastic structure, and a porphyritic 

 habit. Near the Jewett station, York, Maine, a narrow 

 vein carrying pyrite and molybdenum was found. This 

 vein is the only evidence of ore mineralization seen in 

 the entire area. 



Alkaline Granite. — This rock forms an irregular, 

 roughly U-shaped body, the limb of the U enclosing 

 biotite granite and the syenite stock. The typical granite 

 is characterized by euhedral and anhedral perthitic 

 feldspar, allotriomorphic to poikilitic arfvedsonite and 

 aegerite-augite. Quartz-rich phases, aplitic tendencies 

 and peculiar orbicular fine-grained contact phases are 

 some of the departures from the normal. Although the 

 usual amphibole is arfvedsonite, riebeckite is common; 

 aegerite and aegerite-augite are the usual pyroxenes; 

 ort'hite is seen in almost every section. 



