Chap. I.] general sketch of area. 7 



natural eminence until the coast is approached, when lines of blown 

 sand hills appear, running generally quite parallel to the shore. 



The physical features of the alluvial formations are generally very 

 similar all along the coast. There are the same dead level and huge 

 flats in the delta of the Cauvery as in the delta formed by the Punniar 

 and Guddelom rivers, and also in the band of alluvium which joins 

 those two great alluvial areas with each other, and with the alluvial 

 valley of the Vellaur. 



Along the coast, the narrow strip of beach is almost every where 

 fringed by hillocks and ridges of blown sand, which not unfrequently 

 occur in a double and triple row with all the characters of true '' sand 

 dunes.'''' The sea rolls upon a shelving sandy shore unbroken by rocks 

 of any kind ; hence the coast is remarkably monotonous in aspect. The 

 position of the alluvial formations running far up the valleys of the 

 principal rivers, proves ineontestably that considerable elevation of the 

 land must have taken place since the deposition of the component mate- 

 rials of these the most recent of geological records in Southern India. 



The sandy character of the superficial beds of the alluvium of 

 the deltas of the Cauvery and Punniar, especially at their seaward ex- 

 tremities, is a remarkable feature, and shows that but for the sujjply of 

 water furnished by the rivers themselves to the cultivators, the delta 

 lands would ere long lapse into the condition of barren and desert- 

 like sandy plains. , 



To the south-east, the alluvium extends beyond the southern boun- 



High ground south of ^^""^ ^^^^ ^^ ^^^^ ^^^^ ^^^ referred to, but pro- 

 **^^*'*- ceeding westward from Negapatam, higher ground 



is met with on the south side of the road to Trichinopoly. Tliis higher 

 ground rises at first by a gentle slope over the great flat of the 

 delta, but as we proceed westward, the slope increases, and beyond Tan- 

 jore has become quite abrupt, and is occasionally scarped. The plateau 

 which is formed by this high ground is perfectly similar in character, 

 in structure, and in appearance, to the plateaux before adverted to as 



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