i:: HOLLAND: CHARNOCKlTE SERIES. 



S. \Y. Norway (III) and an acid variety of "pyroxene granulite " 

 from near Penig (IV). 



I II III IV 



SOt 75-54 75*30 7347 72"97 



TiO, undetermined trace 0*12 — 



A1 3 3 1375 11-40 I5'42 1269 



*'£>} 499 5-40 $ 4-55 



MgO 0*69 o'6o 0*20 0*63 



CaO 0-94 075 1 -35 2*33 



K.O 3-34 013 364 3*46 



Na 2 i*55 i'45 5 57 3'i6 



H 2 028 ... ... 013 



ioi'oS 101*03 10070 99'92 



I. By Dr. T. L. Walker, Geological Survey of India. 

 II. Ey Dr. P. C. Roy, Presidency College, Calcutta, 

 Both specimens of charnockite from St. Thomas' Mount. 



III. Hypersthene granite, Birkrem, Ekersund, S, W. Norway. 



C. F. Kolderup, Bergens Museums Aarbog., 1896, No. V 

 (Abstract, Neuesjahrb., 1899, I, p. 445). 



IV. Orthoclase-bearing " pyroxene-granulite", near Penig. Anal. 



quoted by Zirkel, Lehrbuch, III, 252, and Rosenbusch, 

 Gesteinslehre, p. 486. 



Garnetiferous leplynite. 



Near its margins, especially where it comes into contact with 

 masses of norite as seen near the railway station at Pallavaram, the 

 charnockite loses its compact texture and dark colour, and passes 

 into a friable, cream-coloured rock, which is sprinkled with pink 

 garnets. The signs of dynamo-metamorphism, so evident in the 

 field, are confirmed by an examination cf this rock under the micro- 

 scope. The weaker minerals have been crushed and are surrounded 

 with granulated selvages, whilst the fragments of quartz show 

 very strongly marked undulose extinctions. The proportion of 



( 24 ) 



