260 





C. A. 



SUSSMILCH. 



Norm.. 



Classification. 



Orthoclase 



.. 723 



Class II Dosalane 



Albite 



.. 67-59 



Order 5 Germanare 



Anorthite 



.. 5-56 



Rang 2 Monzonose 



Nephelite 



2-27 



Sub-rang 5 x 



Corundum 



.. 0-41 





Olivine 



.. 2-52 





Magnetite 



2-32 





Umenite 



.. 2-74 





Hematite 

 Apatite 



.. 6-24 

 ... 0-34 





This rock differs strikingly from the Gloucester Buckets 

 rhyolite, first in its very high soda content and correspond- 

 ing low potash content, and second in the large proportion 

 of iron oxides, particularly hematite. Some nephelite is 

 shown in the "norm," but none of this mineral has been seen 

 in the rock slides. The amount of hematite shown in the 

 " norm " is somewhat unusual, and this probably represents 

 altered magnetite, but owing to the very fine grained tex- 

 ture of the rock this point could not be readily investigated* 

 This magma is evidently a somewhat uncommon one as no 

 magnetic name for this type appears in the quantitative 

 classification table. If no name has yet been applied to 

 this type of magma the writer would suggest that of 

 Gloucesterose. 



I. No. 1 Flow, Burindi Series, Analyst W. G. Stone. 

 II. No. 2 Flow, Burindi Series, Analyst W. G. Stone. 



III. Gloucester rhyolite, Kuttung Series, Analyst W. G. Stone. 



IV . Rhyolite, Mount Bright, Pokolbin, Analyst J. 0. H. Mingaye. 



V. Rhyolite, Paddy's Hill, Raymond Terrace, Analyst W. J. 

 Greig. 



VI. Keratophyre, The Gap, Gloucester Buckets, Analyst W. G 

 Stone. 



