1836.] 



Neelgkerries and KoondahS. 



233 



which all the sections for the road show, as I have said before, an ap- 

 parently stratified rock decomposing, which surrounds and overlays it ; 

 this makes me believe that what seem to be strata are only apparently 

 such, and it is very probable that they are small segments of large 

 concentric laminae, into which the granite has decomposed. Notwith- 

 standing the diversity of the two rocks forming the Sispara group, 

 basalt and granite, it is curious to remark that their external surface has 

 the same black appearance, particularly at a distance, which might 

 induce an error. 



Descending along the half finished ghaut, the greatest number of 

 rocks projecting on both sides are granite, similar to that of Murray- 

 pet, but of a finer grain ; pegmatite in larger masses associates with it. 

 Lower down the granite acquires, in addition to the three minerals, a 

 few garnets, and it seemed to me as if assuming a certain degree of 

 stratification. The whole length of the precipitous sides of the hill, 

 along which the new road is cut, is traversed by numerous basaltic 

 dykes of enormous dimensions, and, in some places, huge laminse of it 

 are laid, mantle-shaped, on the nearly vertical sides of the hill, the 

 lowest portions of which, having been detached and hurled down the 

 precipitous declivity, the remaining la mines are seen holding still to 

 their precarious attachment, ready soon to join the fragments which ar@ 

 seen below scattered about, or heaped in great confusion, near the road. 



Descending still, the rock appears to contain more hornblende and 

 more garnets, although in the deep nullahs it has still the granitic com- 

 position; the consequence of this additional mineral being their decom- 

 position into a red mould, very nearly similar to that of the N e eigne r- 

 ries.* 



As circumstances prevented me from going lower down the ghaufc 

 than six miles, I cannot, from personal inspection, say what is the rock 

 which prevails at the bottom of the pass ; but, from a specimen brought 

 up by one of our party who descended so far, it appears that garnets are 

 very abundant in the rocks lower down ; since the specimen he picked 

 up, from among the splinters of a block just blasted, proved to be an 

 assemblage of garnets with a scanty portion of magnetic iron (No. 152). 



I hope to be excused, if in this, as well as in other places, I should 

 mix with the geological observations some paragraphs of personal nar- 

 rative, or rather descriptions and reflexions suggested by new scenery 

 and new objects, such short digressions, besides relieving the mind from 

 the fatiguing attention demanded by dry scientific subjects, affording* 

 information regarding topography, scenery, and other agreeable and in- 

 teresting matters. 



* Dr. Heyne long ago remarked that red. soil prevails where sienlte forms the araar^t 

 ground-rock.— Tracts, etc. paje 349. 



