Mr Calder oti the Geology of India. 157 



ever, by granite, which passes under it and forms its basis ; some 

 elevated points, such as Naggery Nose, having only their upper 

 third composed of sandstone and quartz, while the base is of 

 granite. 



The rocks above enumerated, with the addition of the iron- 

 clay and basaltic rocks, occupy extensive portions of the valleys 

 of the Kistna and Godavery, covered in some places by the 

 black trap soil. The granite rocks, on which they rest, are of- 

 ten penetrated, and apparently heaved up, by injected veins, or 

 masses of trap, and dikes of greenstone. Mr Calder hopes soon 

 to be enabled to lay before the society a detailed description of 

 the curious formations, accompanied by sections of the strata, 

 between Madras and Hydrabad. The waters of the Kistna and 

 Godavery expand as they approach the sea, dividing into nu- 

 merous branches, and depositing their alluvial contents, during 

 inundations, over a considerable extent of land bordering the 

 coast. The largest portion of deposites consists of decayed ve- 

 getable matter, yielded by the extensive forests through which 

 they flow ; and here may be noticed the characteristic difference 

 that marks the alluvial deposites of the principal river of the 

 south, the Cauvery. This river, flowing in a long course 

 through the Mysore country, over an extensive and generally 

 barren surface of granitic and sienitic rocks, with scarcely any 

 woods or jungle on its banks, brings down little or none of de- 

 cayed vegetable alluvium ; but a rich yellow clay, produced by 

 the felspar, which predominates in the granites of Mysore and 

 the south, and which, mixed with carbonate of lime, renders the 

 plain of Tanjore by far the most fertile portion of the south of 

 India. Passing on to Vizagapatam and Ganjam, the granite rocks 

 appear occasionally covered by laterite. The granite of Viza- 

 gapatam assumes a new and singular appearance, being small- 

 grained, and intimately intermixed with amorphous, or uncrys- 

 tallized garnets, in round grains or specks. This peculiar rock 

 passes into the province of Cuttack. The only information we 

 possess regarding that interesting district, is derived from Mr 

 Stirling'*s valuable paper in the last volume of the Asiatic So- 

 ciety's Researches. The rocks of the granite class form the 

 basis and predominant elevations of this district. They are re- 

 markable for their resemblance to sandstone, and abounding in 



