1836.] 



Neelgherries and Koondahs. 



233 



as the masses of the iron ore shoot up ; and therefore, it is fair to 

 conclude, that the last do not overlay the former. 



I must here call the attention of the reader to the almost impercep- 

 tible transition of the cavernous tubular kind of ferruginous conglome- 

 rate, into the uniformly compact heematitic iron ore of this hill s an 

 appearance that I had an opportunity of observing also in the Northern 

 Circars at Pandagaram, near Samulcottah, where the compact, slaty 

 haematitic iron ore is seen passing into a conglomerate very much like 

 iaterite (Nos. 29 and 30). 



The two hillocks S. E., and close to the lake, and on which Cluny 

 and South Down houses are built, are chiefly composed of the same 

 iron ore. The sections in these declivities, on account of the road which 

 goes round the lake, show the ore decomposed into a red clayey earth, 

 imbedded in the lithomargic earth, resulting, as we have seen, from 

 the decomposition of the original sienitic rock. 



Before concluding these details regarding this iron ore, T will point 

 out some particularities, in which (notwithstanding its similarity in 

 appearance) it seems to differ from the Iaterite of the other parts of 

 India, that I have had an opportunity of examining. The rock of the 

 Neelgherries is by no means so cavernous, and has not so many tubular 

 sinuosities as the Iaterite of the Carnatic, Northern Circars, &c. ; it 

 seems also to be richer in metal, and, what appears to constitute a 

 marked difference, it is entirely divested of any quartz, or sandy parti- 

 cles, which abound so much in the Iaterite of other places. Besides, 

 we are told by Doctor Heyne, that in the Iaterite of the Red Hills, 

 Nellore, &c. a marl or carbonate of lime is occasionally one of the 

 ingredients ; no traces of this carbonate are found in the stone of the 

 Neelgherries*. 



That this rock of the Neelgherries is to be classed with haematitic 

 iron ore, rather than with the true Indian Iaterite (an overlaying rock), 

 is very probable, considering that rocks similar in appearance to it are 

 found in Europe, while the last is peculiar to Indiaf. 



It is said of the Indian Iaterite, that it is associated occasionally with 

 trap. On the Neelgherries, basaltic dykes are not rare, yet I never saw 

 what Voysey remarked in other parts of India, viz. the passage of 

 basalt into wacke, and into iron clay, (by this last name, meaning 

 Iaterite) ; another additional difference between the two rocks. 



Hitherto no organic remains have been found in this rock on the 



* Tracts. 



•i- If my memory serves me right, I think I saw in the museum of the Asiatic Society 

 Of Bengal, a specimen marked " black, brown, solid and perforated iron ore, from Poetz 

 in Upper Lusatia," which appears to me similar to the Neilgherrie's haematitic, cavernous 

 iron ore. 



