24 foote: geological structure of the eastern coast. 



thick deposit of red soil which overlies it. Traces of a similar limestone 

 were also noted to the south-west and east of Irslagundum, a village 

 about 2 miles to the west-by-north. Both these beds belong to the 

 western schistose band. 



A small but very remarkable bed of impure crystalline limestone 



occurs at Punugodu (Poonoogodoo) , on the right 

 At Punugodu. . , 



bank of the small Makeru river 5 miles east- by- 

 north of Kanigiri. The bed forms an anticlinal semicircular curve 

 about 200 yards in length, the dip trending from west to nearly 

 south-east, and the bed being from 6 to perhaps 10 feet in thickness. 

 In the purer parts of the bed the limestone is of bluish or greenish- 

 white colour, but with it are interbedded many thick chert-like laminse of 

 a reddish mineral much resembling calderite (massive garnet). In 

 parts of the bed these laminse greatly exceed the limestone in quantity, 

 With cleavelandite and and in others, especially near the base, the calca- 

 e P ldote - reous laminse disappear altogether. At the base 



the bed is very epidotic — epidote forming to a great extent the laniinse 

 between the highly silicious limestone. Rather higher up the chert-like 

 laminse consist of a mixture of epidote (approaching to pistacite) and 

 calderite. Near the southern end of the curve some of the partings 

 have a perfectly granitoid texture, and look much like small granite veins 

 injected between the planes of deposition; probably they are merely 

 results of metamorphism. The two ends of the curve terminate abruptly, 

 as if faulted against the adjoining granitoid gneiss ; but the junction is 

 too obscure to speak with certainty as to the faults. No eastward exten- 

 sion of the beds can be made out either in the bed of the river or on its 

 left bank. A couple of miles down the river I observed several large 

 blocks of epidotic rock, doubtfully in situ, in the bed of the river 

 close to the right bank opposite Patha Garlapetta. In texture and 

 lustre the epidotic mass strongly resembled a green felsite. They also 

 resembled, though not very closely, the epidotic base of the Punugodu 

 bed. I have seen no limestone elsewhere which resembles ,the Punugodu 

 bed, but calderite was found in connection with crystalline lime- 

 . ( 24 ) 



