MEMOIRS 



OF 



THE GEOLOGICAL SURVEY OF INDIA, 



The Charnockite series, a group of Arch^an 

 hypersthenic rocks in peninsular india. by 

 Thomas H. Holland, A.R.C.S., F.G.S., Officiating 

 Superintendent, Geological Survey of India. 



INTRODUCTION. 



The older workers on the Geological Survey in South India fol- 

 lowed the prevalent theories of the day in considering the Archaean 

 gneisses and schists to be merely sediments in a highly advanced 

 stage of metamorphism ; but Mr. R. Bruce Foote l has recently ex- 

 pressed an opinion that such a conclusion needs revision, and the task 

 now left us is to determine which of these old gneisses are of igneous 

 origin, and which show evidences of being merely metamorphosed 

 sediments. 



The first duty, evidently, is to define and separate from their 

 associates the groups which show, throughout their constituent 

 members, a sufficient similarity of family characters to indicate 

 identity of origin and a genetic relationship one to another. The 



» " The Geology of the Bellary District. " Mem. Geol. 8-urv. Ind., Vol. XXIV (1895), p. 27. 

 Memoirs of the Geological Survey of India, Vol. XXVIII, Part 2. 



B ( I ) 



