16 



Geology of the Country 



[July 



the water, are hornblende rock, with thick veins of quartz, which seems 

 also to be the prevailing rock all over the plain. 



Goondlapet. — This is a walled village, with a dry ditch round it, 

 which gives an opportunity of examining the rocks below the soil, 

 while the different kinds of stones, employed in the construction of the 

 walls, show those which prevail in this neighbourhood. 



Many of them have a stratified appearance, in which the prevailing 

 mineral is actynolite, with hornblende and a flesh coloured felspar 

 (No. 55). In the walls I also found many blocks of a very crystalline 

 sand-stone, and some of quartz rock (No. 56) ; there are stones of a 

 beautiful chloritic porphyry (No. 57), some of green-stone, of gneiss, 

 of granite, &c. 



All these stones must have been brought from some distance, since 

 the only rock about the place, in sicu, is the actynolite schist, to be seen 

 in the lower parts and floor of the ditch, and in the streets of the vil- 

 lage (No. 58). This schist has strata of quartz, conformable to those 

 of the slate. 



Between the western wall, and the houses of the village, the actynolite 

 schist is coated with a thick deposition of ancient kankar, as hard as 

 the old travertino, although its texture is not so crystalline. It is com- 

 posed of a calcarious paste of a grey colour, imbedding chiefly angu- 

 lar, or slightly rounded, pieces of a reddish limestone, besides pieces of 

 quartz, actynolite slate, hornblende, felspar, talc, &c. In short it forms 

 a real breccia. 



Besides incrusting the schist, this ancient kankar is seen in large 

 isolated pieces implanted in the soil, and in the streets of the village. 



Goodloor.— Goodloor stands at the commencement of the ascent to 

 the Neilgherries, at the foot of a very high hill of the Wynaad group. 

 The blocks all about the village are sienitic granite. 



End of the first Journey. 



Second Journey. — The geological appearances of the country, be- 

 tween Madras and Allampaucum, having been described in the fore- 

 going pages, I shall begin the notes of the second journey from the 

 last mentioned place, whence we diverged towards the south. 



Leaving Allampaucum, and proceeding west, the blocks, on both sides 

 of the road for some miles, are of foliated felspar with very little quartz 

 (No. 59). 



As we approach Arcot these masses in the plain are granite, and we 

 are informed by Buchanan that the hills about Arcot and Vellore are 

 granite (a) (No. 60). 



(a J Journey vol. I. page 17, 



