484 H. S. JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. 



of the section. As the thick aplitic veins curve up 

 rapidly, the specimen comes from a point 70 or 80 feet 

 from the nearest point on the lower vein. The rock here 

 resembles specimen I very closely, the only difference of 

 importance being that the quantity of ilmenite and mag- 

 netite is much less, and that there is little apatite, and 

 practically no biotite. This supports the view that ilmenite 

 and apatite are most plentiful in the main rock near the 

 aplitic veins. 



Series II. Specimens from the Emu Quarry. 

 Specimen L. 

 Locality. S.E. corner of Emu Quarry, within 5 cm. (two 

 inches) of the junction with the shale. Megascopically 

 very similar to specimen B previously described. 



Microscopic Description. Texture : Orystallinity, non- 

 crystalline; grainsize, porphyritic in olivine — phenocrysts 

 average 1 mm. in length ; base 0*1 mm. Fabric, pilotaxitic 

 approaching panidiomorphic, as the augite and felspar 

 crystals are mostly nearly idiomorphic. 



Minerals Present. 



Corrected for decomposition. 



By weight as measured. 



Felspar 



37*6 



Felspar 



37*0 



Augite 



33*6 



Augite 



33*7 



Olivine 



21'1 



Olivine 



20*1 



Iron Ores 



7'4 



Iron Ores 



7'4 



Biotite 



0*5 



Serpentine 



1*0 



Apatite 



O'l 



Biotite 



0*5 







Analcite 

 Apatite 



0*2 

 0*1 





100*0 



100*0 



The minerals have the same characters as those described 

 for the previous specimens. The olivine is little decomposed. 

 The analcite occurs in two forms, interstitialiy and in 



