Mr Calder on the Geology c)f India. 165 



general, by forests of the tallest trees, and impenetrable jungles, 

 which admit of gaining but a vague and scanty l^nowledge of 

 the mineral treasures with which they probably abound, if we 

 might be allowed to draw inferences, from the striking analogy, 

 in geological feature and outline, between the mountain-ranges 

 and western coast of the South American Continent and that 

 just described, in some of which traces of copper, gold, silver, 

 and other ores, have been found. 



Proceeding on to the eastern side of the peninsula, and north- 

 ward along the foot of the mountains, we observe a country dif- 

 fering very considerably from the Malabar coast in appearance 

 and geological character. The plains of the Coromandel coast 

 form rather a broad, though unequal, belt of low land between 

 the mountains and the sea, exhibiting the alluvial dcposites of 

 nearly all the rivers and streams that descend from the southern 

 portion of the table-land. The mountain-chain that forms the 

 eastern boundary of the peninsula, after a short northerly course 

 from Cape Comorin, begins to diverge to the east, near where 

 the great valley of Coimbitoor (already" mentioned) interrupts 

 its continuity. From thence it breaks into a succession of pa- 

 rallel ranges, inferior in elevation and in unbroken continuity, 

 to the western chain, and, in the further progress northward, 

 after breaking off into subordinate hilly ranges, occupying a 

 wide tract of unexplored country, and affording valleys for the 

 passage of the great rivers that drain nearly all the waters of the 

 peninsula into the bay of Bengal. This eastern range may be 

 said to terminate at the same latitude as that of the commence- 

 ment of the western. Granite rocks, and principally sienite, 

 seem to form the basis of the whole of these eastern ranges, ap- 

 pearing at most of the accessible summits from Cape Comorin to 

 Hydrabad. Gneiss and mica-slate, that form the sides and base 

 of the mountains, are sometimes seen, as also clay-slate, horn- 

 blende-slat^, flinty-slate, chlorite, and mica-slate, and primitive 

 or crystalline limestones, affording, in some places, marbles of 

 various colours, as in the district of Tennivelly, where also gra- 

 nite appears rising above the surface, in remarkably globular 

 concretions, and in perfectly stratified masses, forming low de- 

 tached hills near Palemcotta, the strata of which dip at an angle 

 of about 45" to the south-west. Partial depositcs, too, of overly- 



