THE CRYSTALLINE COMPLEX. 3 



On the geologically colored map which accompanies this report 

 eight rock groups have been distinguished as follows: — 



1. Crystalline Complex. 



2. Granitoid Gneiss. 



3. Charnockite Series. 



4. Khondalite and associated rocks. 



5. Cuddapahs or Vindhyans. 



6. Gondwanas. 



7. Later ite. 



8. Dyke Rocks. 



In the present state of our knowledge of the geological relations 

 of the group of crystalline rocks which make up the northern part of 

 the eastern Ghauts, it is impossible to speak definitely as "to their 

 genetic and chronological relations to one another. Detailed study 

 has not been attempted as will become evident when it is stated that in a 

 little over five months field work in Vizagapatam and Kalahandi nearly 

 seven thousand square miles was mapped, most of the country being 

 altogether new ground. In one outcrop, to be more fully described 

 hereafter, I observed what appeared to be fairly well banded gneisses 

 in contact with Cuddapah slates which shewed well-marked contact 

 metamorphism ; if we may rely on this interpretation of the pheno- 

 mena, we will be forced to regard some of the "gneisses" placed in 

 the Crystalline Complex as nearly well banded granites of post 

 Cuddapah age, a conclusion little in accord with the accepted views as 

 to the relative ages of these two rock groups. 



II.-THE CRYSTALLINE COMPLEX. 



1 have attempted to divide the crystalline rocks of Kalahandi into- 

 four groups, three of which have fairly distinct relationships and are 

 described separately in the three following chapters. The remaining 

 crystallines are dealt with in the present chapter. It seems very 



