Trans. N.Z. Inst., Vol. LIII 



Plate XXVII. 



Fig. 1.- 



Fig. 2- 

 Fig. 3.- 



TFig. 4.- 



Fig. 5, 



a large plagio 

 coarse ground- 



-A porphyrite from the dyke complex of Mine Bay. Part of 



clase crystal is recognizable, and the irregular nature of the 



mass can just be discerned. Crossed nicols. X 26. 

 -Sagenitic pseudomorph after biotite in porphyrite from Mine Bay area. X 150. 

 -Quartz-mica-porphyrite from intrusion near old copper-mine. Phenocrysts 



of biotite and plagioclase can be seen. Crossed nicols. X 26. 

 -A quartz phenocryst from a homblende-biotite-quartz-porphyrite forming 



intrusion a little south of Miner's Head. The crystal shows a distinct 



corrosion border. Crossed nicols. X 26. 

 -Pilotaxitic andesite from dyke in oldermass of Mine Bay Creek. Crossed 



nicols. X 26. 



