42 HOLLAND AND TIPPER : INDIAN GEOLOGICAL TERMINOLOGY. 



the Dharwars. It thus appears that some of the gneissose gra- 

 nites are younger and some much older than the typical Dhar- 

 wars. But there is a marked contrast between the age of the 

 Dharwars and associated gneisses and schists and the unmeta- 

 morphosed Cuddapahs and other sedimentary rocks resting on 

 them ; hence the various kinds of gneisses and schists have 

 been grouped with the Dharwar types to form the Archaean 

 group (T. H. Holland, Imper. Gazetteer, I, 59, 1907 ; Trans., 

 Min. and Geol. Inst., Ind., I, 47, 1906). This arrangement 

 differs from that recognised by R. B. Foote, who regarded the 

 Dharwar system as essentially younger than the associated 

 gneisses, which he considered to be Archaean (Mem., Geol. 

 Surv., Ind., XXV, 26, 1895). T. J. Newbold and others in the 

 earlier part of the nineteenth century referred to the Dharwars 

 as " hypogene schists," and regarded them as older than the 

 associated gneissose granites. 

 The Mysore Geological Department in their work on the Dharwars 

 have come to the conclusion that as a whole they are older 

 than the gneissic complex with which they are associated. 

 The Dharwars have been split into two divisions, hornblende 

 schists and epidiorites (altered lava flows) below, with chlorite 

 schists above. The gneiss is considered to be intrusive 

 into both of these and the intrusion took place by a series of 

 lateral invasions of more or less horizontal sills of varying 

 dimensions and different in character from the ordinary intrusion 

 of an acid rock. The so-called " conglomerates " at the base of 

 the hornblende schists in the Kolar belt and at various horizons 

 above in other areas are looked on as autoclastic crush forma- 

 tions. 

 W. EY Srneeth (Mysore Geol. Deft., Records, xi, General Report. 

 36, 1910) gives the following sequence for the Chitaldrug schist 

 belt from above downwards : 



7. All dolerite dykes so far as known. 



6. Chitaldrug granite. 



5. General gneissic complex forming the bulk of the country 

 on either side of the schist belt and intrusive into the 

 latter. 



4. Intrusive granitic material, including the so-called ferruginous 

 sandstones of the Guddadrangavanhalli (G. R.) formation 

 and Aimangala conglomerate. Age doubtful. 



