GRITTY SANDSTONES. 43 



alluvium o£ the Ammau Aru, and further west under the great red 

 Sections north of Cape ^oi\ deposit which flanks the spur of the Kathadi 

 Comonn. Malai stretching" south towards Cape Comorin 



These are of precisely the same character as the grit beds described in my 

 notes on South Travancore (Rec. G. S. I. Vol. XVI, page 39), of which, 

 indeed, they are extensions. In colour these grits are white, pale drab 

 or grey, mottled with red and brown in various shades. Among the best 

 sections of these grits are those to be seen in the bed of the Kothan 

 Aru and its various small tributaries, especially one (not shown in the 

 map) which flows parallel with the old salek, or avenue of trees, lead- 

 ing from Panagudi to Cape Comorin for about half a mile. Another 

 good section is to be seen in a channel cut through the thick red soil 

 to convey water to the Comaraveram tank about | of a mile to the 

 south-east. The beds have a general dip to the southward, but roll 

 about a good deal on a small scale j they show a good deal of local false 

 bedding. The grits are exposed also in numerous garden wells, but all 

 the sections are very shallow, and in no case was the base of the forma- 

 tion seen. 



Eastward of the Kothan Aru are other gritty sandstones of grey 



Sandstones of doubt- and drab colour, but more friable and shaly and 



*^^ ^S^- of a decidedly younger aspect. They are exposed 



in the bed of the Panagudi ualahat and above Perangudi (Perrungoody) . 



Of equally doubtful position is a brown gritty sandstone considerably 



affected by infiltration of kankar, which is exposed to some extent 



Nedden Kulam out- ^^ ^^^ shallow bed of the stream which flows 



^^°^' out of the large tank north of Nedden Kulam 



4 miles west by north of Shatankulam ^ (Shalaungcolum) in Tenkarai 



taluq. As the bedding is nearly horizontal, the thickness exposed in 



the very shallow section amounts only to 2 or 3 feet. This brown 



sandstone, in which I was unable to detect any fossils, bears little 



or no resemblance to any member of the grit series which came under 



my notice in the south, but beyond that there is no reason why it 



might not be a remnant of the former extension of the Cuddalore for- 



( 43 ) 



