ALLUVIAL FORMATIONS. 77 



The sandy tufa of the banks appears to be highly adapted to contain 



organic remains, but unfortunately none showed at the time of my visits, 



though they were very carefully sought for. The tufa looks so likely 



for them that it is highly desirable the banks should be from time to 



time carefully examined. No mammalian or reptilian remains were 



found in any of the fluviatile alluvia in the south. The rivers flowing 



into the sea south of the Tambraparni carry down sand and fine gravel 



as sediment, but they also carry very large quantities of calcareous matter 



in solution, and form large deposits of tufa in their banks or beds. 



The tufaceous deposits thus formed are mostly massive (sheet kankar), 



but they all here and there form small quan- 

 Great tuiapeous lime- 



stone deposits generally titles of the Vermicular and nodular varieties, 

 massive in character. . 



This latter rorm is developed to a remarkable 



extent in thp valley of the Nambi-ar opposite to Chittoor, at its junction 



and its southern tributary, the Anaikulam nullah. 



The great spreads of massive alluvial tufa, which are more extensive 



and remarkable in South Tinnevelly than in any 

 More important than 

 in any other southern other part of the Indian peninsula that I am 



acquainted with, deserve special enumeration, and 



may for convenience be taken in order from north to south ; — 



1. The valley of the Sevandipatti (Shaminthaputty) nullah, 6 miles 



Tufa deposits at Se- south-east-by-south of Ealamcotta, shows a very 



ipa y, large spread of this rock which extends up and 



down the valley near Sevandipatti village, and shows also very largely 



above Ayanapatti (lyanauputty). There is a considerable show of it 



also to the south of Sevandipatti resting on the gneiss directly. 



3. The Karseri tank overflow channel shows a great quantity of the 



massive kankar to the north of the village, and 

 Karseri, , . . 



there is a noteworthy show of it also in the south- 

 ern branch of the nallah which flows past Arasakulam (Urshacolum). 

 3. On the western side of the great Megnanapuram teri and a little 

 West of the Megnana- ^^ the westward of Yelluvaraimuki (Yellavoor- 

 puraiu ten. mookee) there is a considerable show of massive 



( 77 ) 



