SUB-RECENT MARINE BEDS. 69 



or drab colour, and containing large numbers of marine shells of living 

 species. Of the shells some appear perfectly f ossilized, others are but very 

 slightly altered and retain part of the natural colouring. The latter lie 

 witliin reach of the constant action of the surf spray ; the former lie 

 above it, and are exposed to the bleaching action of the sun. This calca- 

 reous sandstone attains a maximum thickness in the eastern and central 

 parts of the cliff section of about 10 to 12 feet, but thins out to the 

 westward till close to the village where it is covered by blown-up beach 

 sand. Its connection with the gritty limestone of the eastern end of the 

 Kudung Kulam east plateau could not be traced, being obscured by the 

 teri sand and surface travertine above spoken of, besides which tlie 

 surface is much hidden by thorny scrub. If this low level calcareous 

 sandstone is an extension of the higher lying gritty limestone, there must 

 be a considerable southerly roll of the bedding to the north of the cliff 

 section, for in the latter the bedding is horizontal. The relation of 

 the two formations must for the present remain undecided. One 

 point, however, in favour of their being of the same age and horizon 

 consists in the remarkable similarity of the rather soft mottled grit 

 underlying the calcareous sandstone at Idindan Karai to the mottled 

 grit exposed below the Kudung Kulam limestone plateau on the path 

 leading from the village to the beach (see page 42). In both sections 

 the mottled grit appears to be conformable to the overlying calcareous 

 formation. The base of the grits is not seen at Idindan Karai, beino- 

 hidden by the beach sand and being close to the edge of the surf 

 which during high tides, or in rough weather, breaks against the foot 

 of the cliff and undermines it very considerably owing to the great 

 hardness and tenacity of the calcareous sandstone, which projects for 

 several yards beyond the soft grit bed. Occasional falls of the sand- 

 stone take place, and the fallen masses form for a time a very effectual 

 breakwater against the further encroachments of the surf. The cliff 

 showed smaller traces of the destructive action of the surf than mio-ht 

 have been expected from the very exposed situation which it occupies 

 on the coast. This is no doubt due to the protective action of a reef 



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