368 



Geology of the Deccan. 



Extent of Trap Region, #c— I will now offer a few observations on 

 the amazing extent of the trap, laterite, nodular limestone, granite, and 

 gneiss formations in the peninsula, limiting their application to 25° of 

 north latitude. My personal knowledge of the country extends from 

 the sea on the western side, to Arungabad, in 75° 33-, and Sholapoor, 

 75° 53' east longitude; north, nearly to Kandeish, and south, to Beeja- 

 poor and the Kristna river. Captain Dangerfield takes up the country 

 on ihe north, nearly where my knowledge of it terminates, and says, 

 " It (Malvva, including the Vindhya range) appears to constitute the 

 northern termination of a very extensive secondary trap formation, 

 which extends from the extremity of the Dukhun, and probably even 

 Mysore, forming all the country above the ghats, and part of the 

 plains below, on the western side of the peninsula, including the islands 

 of Bombay, Salsette, Elephanta, &c."* He carries the continuous 

 trap north to Neemutch, in latitude 24° 27', at 1476 feet above the sea. 

 Its western limit is at Dohud, longitude 74°. Major Franklin and 

 Captain Coulthard take it up in the eastern limits of Malwa, and trace 

 it through Sagar ; and it continues to an unknown extent towards 

 Sohagpoor and the source of the Nerbuddeh river, on the table-land 

 of Amarakantah, in longitude 82« east. Dr. Voysey describes its 

 eastern limits at Nagpoor, latitude 21° 10' N., and longitude 79° 14' E. 

 at 1000 feet above the sea. Mr. Calder states it passes from Nagpoor 

 southward by the confines of Hyderabad, as low as the 15th degree 

 of latitude, and taking a north-west direction terminates on the sea- 

 coast at Bancoot or Fort Victoria, in latitude 18°. But specimens of 

 rock shown to me from the Kolapoor country above the ghats, between 

 the parallels of latitude 16° and 17° N., bear testimony to the trap 

 extending nearly a degree and a half further south along the ghats 

 than Mr. Calder supposed. Indeed its southern limit in the Konkun, 

 Mr. Fraser states to be at Malwan, fifty miles north of Goa.f From 

 the above evidence we have proofs of a continuous trap formation cover- 

 ing an area of from 200,000, to 250,000 square miles, a phcenomenon 

 unexampled in any other country whose geological structure has been 

 examined. It appears to me, however, that the above are not the ab- 

 solute limits of the trap. Dr. Buchanan! and Mr. Jones§ describe the 



* Malcolm's Central India, Appendix, p. 320. 

 + Geological Transactions, 2d Series, part 1. p. 153.' 

 % Gleanings of Science, vol. iii. January, 1831, p. 1, 

 \ Physical Class, Asiatic Researches, p. 165, 



