CHAPTER II. 



SYNOPSIS OF PREVIOUS OBSERVATIONS. 



The earliest writer on the geology of the South Mahratta Country 



appears to have been Lieutenant C. P. Rigby, 16th 

 Lieutenant Rigby. 



Regiment, Bombay Native Infantry, whose ac- 

 count of a collection of geological specimens for presentation to the 

 Bombay Asiatic Society was published in volume VIl of the Bombay 

 Geographical Society's Transactions. In this paper, Mr. Rigby described 

 the town of Talikote as standing on an extensive bed of very fine clay 

 (limestone really) used for building and roofing purposes, and occurring 

 of many colours. He noticed the occurrence of some limestones fit fof 

 lithographic purposes; also the saltness and bitterness of the water of the 

 Ddn River. He describes the country south of the Krishna, towards 

 Belgaum, as almost wholly composed of red sandstone and red ferru- 

 ginous claystone (?) with intervening plains of rich black soil. The fact 

 of the Jain temples, which stand above the falls of the Ghatprabha 

 at Gokak, being built of the local sandstone, is also mentioned. 



Dr. Voysey's observations on the "iron-clay^' of Bidar have a 



direct bearing on the geology of our area, for the 

 Dr. Voysey. 1819. . ^ 



iron-cIay plateaux, occurring to the north-east of 



Galbarga, are extensions of those capping the l)eccan trap in the Ghat 

 region. He Was the first to point out the formation of iron-clay by de- 

 composition of basalt and other volcanic rocks rich in iron. He used 

 the term iron-clay exclusively. In his description of the country at 

 and around Bidar, he noticed the striking flatness of the isolated moun- 

 tains; the resemblance of the iron -clay to the Nellore rock, which is a 

 true sedimentary laterite. He dwelt specially on the passage of the 

 iron-clay into '' wacke and thence into basalt,^'' and instanced a ease in 

 which the very distinct transition took place within a distance of 

 3 feet. 



( 19 ) 



