92 GEOLOGY OF TRICHINOPOLY; &C. [ChAP. IV. 2, 



The aspect of the country traversed by these veins of magnesite is 



altogether quite peculiar^ and so unlike any thing 

 Aspect of this area. i i • i i • i 



else which has ever previously come under our 



observation, that we find it difficult to institute a comparison with 

 any other phenomenon seen elsewhere. 



The southern or smaller of these altered areas has the form of a low 

 broad ridge^ seamed in every possible direction by the veins of magnesite, 

 which being harder than the main mass of the altered rocks, stand 

 out from 3 or even 4 feet down to an inch or two over the general 

 surface, and seam the ridge all over as with a rude net- work. The veins 

 generally underlie at a high angle, or are vertical. The course of the veins 

 is generally straight for several yards ; they then turn and follow some 

 other directions, but often divide and twist about in a most puzzling 

 manner. In colour, the veins, where freshly broken or exposed by recent 

 denuding action of heavy rains, are of a pure white, very dazzling and 

 painful to the eyes when the sun is shining brightly. Where the veins 

 have been long exposed to the weather, they have become much blacken- 

 ed, and wherever the rock shows any asperities, or when seen from a dis- 

 tance, present, as might be expected, various shades of grey. Occasionally, 

 however, the grey or brownish stain extends through the magnesite itself, 

 indicating in all probability the admixture of some foreign mineral sub- 

 stance. In width these veins rarely exceed 2 to 3 feet, and are generally 

 very much smaller. Those occurring in the northern area are generally 

 larger than the southern ones, but not so well defined, and more kunkur- 

 like in appearance. Though the magnesite veins are white in colour, these 

 so-called Chalk Hills present but a very faint resemblance to hillocks of 

 true white chalk, which are generally quite smooth, and covered with turf, 

 whereas this magnesite-bearing region is far from being generally white, 

 and is eminently dry, rugged, and barren, hardly any thing but a few 

 stunted shrubs, chiefly of the genus Dodoncea, (?) and a thorn-bearing acacia 

 (Acacia latronvmj growing where the white veins are most abundant. 

 ( 314 ) 



