88 FOOTE : GEOLOGY OF MADURA AND TIHNEVELLY DISTRICTS. 



they were originally imbedded^ and is easily removed by hydrochloric 

 acid. The grains of sand are well rounded. 



From the description given of the red sands of the Nefud or great 

 desert in northern Arabia, by Palgrave and by Lady Anne Blunt, and 

 quoted in the paper on these sands read before the Geological Society o£ 

 London (Quar. Jour. Geol. Soc. London 1883, Vol. xxxviii), it is clear 

 that the teris bear a great resemblance, though on a very much smaller 

 scale to the hills of blown red sand of the Arabian desert. The " fuljes'' 

 or horse-shoe shaped hollows do not occur characteristically in the 

 teris, probably because of their much smaller extent and dimensions as 

 compared with the vast ridges and hills in the Nefud. It is unfortu- 

 nate that the notes on the Arabian red sand tract contain no hints to 

 help in explaining the origin of such deposits. 



Teris, as the red sand hills are locally termed in Tinnevelly, are un- 

 Teris known only in known in many districts of the south, and have 

 two other regions. been described by the geological surveyors from 



only two other districts — the north-western part of Nellore district and 

 the southern part of Travancore.^ In the former case they are of very 

 small extent, and in the latter they appear to be rapidly losing their 

 character as true moving sands, owing seemingly to the exhaustion from 

 some cause or other of the supply of fresh sand. 



The most southerly teri we have to deal with in Tinnevelly is a 



narrow strip close to the coast beginning at the 

 Kotapalle teri. . ,. . 



extreme south point of the district 5^ miles 



north -east-by-north of Cape Comorin. The southern part of this 



strip stretches for nearly a mile south-westward into the Travancore 



State. This narrow ridge is about as high as the equally narrow ridge 



of white coast dune which lies between it and the beach. There is 



hardly any intermixture of the two sands, and the two ridges run 



on together with hardly any break for some 5 miles to beyond 



' See Mem. G. S. I., Vol. XVI, p. 101 on the Geology of the East Coast from Lat. 15° N. 

 to Masulipatam, by R, B. Foote, and Ricords G. S. I., Vol, XVI, p. 31, on the Geology of 

 Houtli Tnivancore, by 11. Bruce Foote, F. G. S., Deputy Superintendent, Geological Sur- 

 vey of India. 



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