■^< iitM-ally idioniorpliic and with anomalous extinction. Plagiodase 

 IS r;ire. The Inotite is distinctly biaxial. Apatite occurs as an 

 accessory and there is a little isotropic chlorite. This rock is 

 found on the ro.id from Waimongaroa to Denniston and traverses 

 sandstones and slates which, from lithological characters, I judge 

 to helong to the f Jokanui System. 



Muscovite Granite. 

 Lntr/ r IhiUordorijp — A coarse grained rock, passing in places into 

 <Ti;int (:Jranito ; of pink felspar, white or sometimes pink quartz 

 and large plates of muscovite. S.G. 2-6 to 2-64. Section : The 

 quartz contains few fluid cavities and shews pressure granulation. 

 Tlie fels{)ars are both orthoclase and plagioolase. Pale brownish 

 garnets, about -OOG in diameter, occur occasionally. Forms 



piagioclase and a little muscovite, with centric texture. The 

 quartzes are from -08 to -02 in diameter, the smaller ones being 

 the commoner ; there is no pressure granulation. The felspars 

 go to -or). Apatite is present as an accessory mineral. The 

 pseudo-sphcrulites go up to about "3 in diameter. They are com- 

 I)osed of irregular radiating crystals of clear quartz and of a pale 

 brownish nuneral, which is fibrous, slightly pleochroic and has 

 straight extinction. It was considered by Mr. Daintree to be 

 prehnite. These pseudo-spherulites are sometimes surrounded by 

 a band of translucent brown (quartz, which extinguishes simultane- 

 ously and is polyhedral. (Plate viii., fig. 1.) 



This rock occurs in loose blocks on Highpeak, and has not been 

 ound in situ. My specimen shews a junction with the rhyolites 

 ouiid HI the same range. liaast, Reports Geological Explorations 

 / "-.P- ^^' *"f^ Geology of Canterbury and Westland, p. 288, 

 <>>yeiiitic Granite Porphyry). Daintree, Trans. N.Z. Institute, 



|;<l^ others "h,iir-like "cry'i'us ^prol.ai'lV' 



