243 HOLLAND : CHARNOCKITE SERIES. 



e, f and & But no facts have so far been obtained to show it* 

 relations to the other foliated eruptives, b y c and d. The writer agrees 

 with the older workers in regarding the charnockite series as part 

 of the Archaean complex, and in placing them in the upper divi* 

 sion of these rocks ; but he considers that their position has been* 

 obtained by intrusive trespass, like that of the anorthosites of 

 America and like that of the hyperites and norites of Scandinavia. 



Study of the charnockite series has brought the writer into, 

 frequent contact with the peculiar stucture referred to by previous- 

 workers in South India as " trap-shotten'\ The so-called u trap-shot- 

 ten " bands coincide with lines of dislocation, and the black tongues 

 and films which superficially resemble compact "trap" have the 

 microscopical characters of mylonite which has been hardened- 

 fritted and rarely half-fused — by the heat generated through the 

 dislocation being confined to narrow bands, and thereby causing a 

 higher focal rise of temperature than would result from a general 

 deformation of the rock-mass. 



The phenomena of schlieren (p. 215) are frequently displayed by 

 the charnockite series. Sometimes acid, coarse-grained contempora- 

 neous veins (p. 219) are found cutting through intermediate and 

 basic masses; sometimes basic segregations are cemented in an acid 

 matrix to produce a kind of primary eruptive breccia (p. 218) or 

 merely occur as isolated bodies in a more ackl matrix. Such included 

 bodies differing in composition from the general rock masses, but 

 nevertheless derived from the same magma and thus genetically 

 related to the latter, the writer would, for the reasons given o& 

 p. 217, distinguish under the name autoliths, in contradistinction to 

 the term xenoliths suggested by Professor Sollas for inclusions of a 

 foreign rock. In most rock-masses such autoliths will be more basic 

 than the matrix in which they are included, but they are not 

 necessarily so. 



As is the case with all large magma bodies, the contacts of the 

 charnockite series with adjacent crystalline formations take the 



( 130 ) 



