238 



Geology of the JSeilgherries. [No. 12, new series. 



This highly picturesque hollow is furrowed by subordinate val- 

 lies, separated from each other by buttresses of rock projecting 

 boldly into the arena, and descending precipitously into the valley 

 below. 



In many places these crags are almost inaccessible. The inter- 

 vening vallies are cut by ravines formed by running streams, whose 

 banks are thickly wooded, and afford shelter to elk, wild sheep, 

 black panthers, and other denizens of the forest. 



The confluence of these streams, at a point a considerable dis- 

 tance down the valley, is the spot from which the scenery of the 

 amphitheatre is most striking. Thence the united waters pursue 

 their course towards the margin of the Hills, descending in cas- 

 cades, and cataracts, till they reach the precipice, over which they 

 must be cast in a magnificent volume of water ; the case, I sup- 

 pose, with all the streams that fertilize the vallies here. 



The buttresses which seem to support the amphitheatre, slant 

 out of the perpendicular at a considerable angle to the southward ; 

 in other words their horizontal lines of cleavage, or the bases of 

 their prisms, have been elevated on the north side by a force from 

 below, which operated prior to the excavation of the amphitheatre, 

 and subjacent valley. 



The rocks of these buttresses consist of : — 



1st. — Compact Felspar, Quartz, and Mica, closely aggregated, 

 and presenting a red color when fractured. With a view to ob- 

 viate the necessity of constantly mentioning the ingredients of a 

 rock when speaking of it, I take the liberty of specifying such va- 

 rieties as have not yet been distinguished by any appellation. 



Accordingly I bestow upon this rock the name of red compact 

 granite. 



2nd, — Compact, Felspar, Quartz, and Mica, of a greenish colour, 

 With equal propriety this may be designated green compact gra- 

 nite. 



By the addition of hornblende it would pass into green syenite. 

 3rd. — The same ingredients, but presenting a white color when 

 fractured. In this rock the Quartz is arranged in plates parallel 



