MANUAL OF THE nIlAGIRI DISTRICT. 85 



The most conspicuous of these superficial escarpments crosses the CHAP. V. 

 hills in a south-west direction from the rise of the Pykara near q^ol^^ and 

 Makurty Peak, and forms the boundary of that elevated portion of Mineralogy, 



the plateau to which the name of the Kundas has been given." 



The rocks which constitute the Nilagiris belong almost wholly to Rock forma- 



Itlie schistose or foliated class, which are included by some ^^^' 

 geologists among metamorphic rocks. But for reasons given, 

 Mr, Blandford regards this appellation as of but doubtful 

 propriety, preferring to restrict himself to the term gneissose 

 rocks, " gneiss being the most known and most typical of the 

 series.^' The other rocks are chiefly alluvial deposits, small 

 basaltic dykes, and some quartz veins. Nowhere above the Granite 

 ghdts has any trace of granite or of rocks belonging to that class ^^^®^*- 

 been found, though in the district below the ghats numerous 

 small granite veins are observable. 



The rocks occurring in the district and neighbouriug tracts Gneissose 

 are very varied in mineral character, and might easily be regarded ''°'''^^" 

 as of Plutonic origin. But though at times their foliated structure 

 is very indistinct, yet they invariably pass into a more markedly- 

 typical gneissose form. They never " form igneous veins or 

 present any appearance of intrusion, ^^ Their foliated character 

 is much more marked in the plains than in mountainous tracts. 



The direction of this foliation, which is fairly constant, approxi- Direction of 

 mately coincides with that of the " southern escarpment of the ^^luitions, 

 Neelgherries, the Bhowani River, the Eastern Ghats, and many of 

 the principal ridges on the surface of the plateau, especially those 

 to the south of Ootacamund. Its prevailing strike is between N,E., 

 S,W. and E,N,E, and W,S,W.'' A few variations occur, notably 

 at Snowdon, . but these are very local. The foliation is most 

 distinct at Kotagiri, but it is rarely strongly marked, and never 

 approaches to a schistose character. The foliation becomes more 

 strongly marked as you descend the ghats, especially the Coonoor 

 ghdt, near Mettapollium. "A coarse hornblende schist, composed of 

 thick alternating laminas of quartz and hornblende, is seen protrud- 

 ing from the ground in large slabs resembling the old tombstones in 

 a country churchyard. ^^ The foliation becomes more compact as 

 you advance into the great Coimbatore plain. 



The principal minerals generally found in varying proportions Minerals. 

 .n these foliated rocks are garnet, felspar, quartz and hornblende. 

 Mica occurs but rarely, and is stated by Mr, Blandford to be an 

 exceptional mineral in South India. Besides the above minerals, 

 'magnetic iron, haematite, specular iron and graphite, and, as the 

 •esult of decomposition, the various earthy forms of the hydratid 

 peroxide of iron, such as ochre and laterite and kaolin," are of 

 ocal occurrence. Of these the oxide of iron is the most abundant. 



