JSriLGHIRI HILLS. 237 



The cuttings on the Cantonment road between the Church and the 

 Club-house of Ootakamund, expose amass of highly 



Ochreous clays. 



ferruginous clay, evidently arising from the de- 

 composition of the gneiss in situ. The bands vary in tint, the varia- 

 tion being probably dependent upon the quantity of hornblende in 

 the original rock. Some of this clay is sufficiently colored to serve 

 as a pigment, but it does not appear that it has ever been tried for this 

 purpose. 



The alteration of Magnetic iron into Heematite is a well known 



result of atmospheric action. The localities on 



Hicmatite. ., , . , ..... i- i • i 



the hills which exhibit instances oi this have 



been already referred to. 



Denudation and recent Geological changes. — In treating of the 

 denudation to which the Neelgherries have been subject, two different 

 and consecutive periods — the former an epoch of marine action, the 

 latter of atmospheric agency, — may be separately considered. 



If the physical aspect of the Neelgherries be compared with that 

 ^, . , i. i^TvT 1 of the lower ranges of the Himalayas, as, for 



Physical aspect of Neel- *= J ' ' 



gherries. example, the hills around Darjeeling, the differ- 



ence, notwithstanding their similarity of lithologic structure, of climate 

 and elevation, is so apparent as to strike the most superficial 

 observer. While the latter hills consist of a system of sharp backed 

 precipitous ridges, drained by a corresponding system of ravine like 

 valleys of enormous depth, the slopes of which up to an elevation 

 of 10,000 feet are clothed with a dense luxuriant forest jungle, scarred 

 here and there with the debris and bare rock surface of a recent land- 

 slip, the former present an undulating surface of smooth grassy hills, 

 and the ravines and gorge-like valleys, so characteristic of the Himalayas, 

 are in the Neelgherries confined for the most part to the outer preci- 

 pitous slopes of the plateau. In the Kundah portion of the plateau 

 we have a country of intermediate characterj the hills being more 



