PART X 



REPORT ON THE PYROXENE GRAJSULITES 



COLLECTED BY THE BRITISH ANTARCTIC 

 EXPEDITION, 1907-1909 



(With Plate) 



BY 



A. B. WALKOM, B.Sc. 



The pyroxene granulites described in this paper were all erratics collected at Cape 

 Royds. They are very similar both in hand-specimen and mineral composition to 

 similar rocks which have been described from other parts of the world, viz., Saxony, 

 Canada, Ceylon, Madagascar, etc. Garnet, which is a very common constituent of 

 these rocks in other parts, is quite absent from this series, while sphene, which is not 

 common in other areas, is a very constant constituent here. 



These rocks, occurring as they do in the form of erratics, cannot be expected to 

 throw much light on the nature of their origin. 



Analyses of two of them have been made by Mr. G. J. Burrows, B.Sc, and myself, 

 with the following results : 



I II 



9992 



These analyses differ considerably in some respects from those published of other 

 similar rocks. The most noticeable difference is in the case of the relative proportion 

 of CaO to Si0 2 . In all similar rocks with a percentage of Si0 2 greater than 70 the CaO 

 rarely goes as high as 2 per cent, and never above 3 per cent., yet in the case of both 

 the present analyses it is considerably above this amount, and in the second of these 



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