GRITTY SANDSTONES. ■ 37 



shingle (from the size of a cocoanut downwards) in moderate quan- 

 tity. 



The second section of outcrops occurs 2 miles further south-west 



and about a mile south-west of Ayangudi in 

 Ayangudi section. • -, it p 



the middle of an extensive scrubby jungle. 



The beds are unlike those east of Shenkarai, as they are rather 

 friable conglomerates of very coarse texture. The matrix, which 

 varies from red to brown-red in colour, is semi-lateritic and ver- 

 micularly cellular to some extent. The enclosed shingle is mostly 

 large and well rounded, chiefly quartzose, and all apparently of 

 gneissic origin. The lowest bed is mottled and more gritty in tex- 

 ture with fewer enclosed pebbles. The dip is southerly at low 

 angles, and the section here, as at Shenkarai, penetrates the strata but a 

 few feet vertically. The base of these beds is not seen, but there can 

 belittle doubt that it rests upon the gneiss, which crops up at both 

 Shenkarai and Ayangudi. 



Eleven miles to the east-by-south of the Ayangudi section, and 

 close to Ammagudi is a section at the edge of the 



Ammagudi section. 



gentle scarp overlooking the Vellar valley in which 

 gritty sandstones are seen peeping out from below the surface laterite. 

 Brown and purple sandstones occur here of sufficient hardness to be 

 worth quarrying into coarse flags for local use. As in both the former 

 cases, the exposure is of very limited extent. 



Traces of these gritty beds are to be seen in the tank below the 

 Sections south of the ^^^^i Kasa Nada Kovil (temple) which stands on 

 ^^^^^^'- the bluff overlooking the Vellar river opposite the 



south end of the Shenkarai hill. Mottled gritty beds are exposed in the 

 Teppa Kulam (square temple tank) at Pallatur (Pullatoor) 4 miles further 

 south. So also % miles to the westward of the latter place at Suragudi 

 (Shooragoody) where approximately horizontal beds of motlled grits occur 

 under the laterite. The grits which are exposed in the temple tank only 

 are very clayey in parts and mottled white, pink, and pale buffi to yellow. 

 Mottled white and yellowish-brown grits are exposed in rain gullies east 



( 37 ) 



