62 



LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



Age of the dykes. 



The South Indian dykes are intrusive in rocks belonging to the 

 Dharwar series, and are probably contem- 

 poraneous with the trap flows in the Cuddapah 

 series of that area (Holland, Op. cit., pp. 36, 37). Those of Nam Hsan 

 must belong to a somewhat later period, for they are intrusive in the 

 granite, which is itself intrusive in the rocks of the Chaung-Magyi 

 series, and I have already given reasons for supposing that this 

 series is of later age than the Dharwars. The Nam Hsan rock is 

 quite different from the Tertiary olivine basalts of Loi Han Hun, 

 described by me in the Records, Geol. Survey of India, Vol XXXVI, 

 Pt. 1, p. 42, and referred to below (p. 314) 



®%kt®m» ML: a rj% • -6M 



From a sketch hy the author. 



Via. 3. The Chaung-Magyi at Gwegyaung. Hpataunggyi in the distance. 



