1838.] Malcolmson on the Basaltic Distriet of I^idia. 203 



^ Proceedings of Societies. 



Geological Society, Nov. 15, 1837.— The reading of a paper was 

 afterwards commenced '* On the Geology of the Eastern Portion of 

 the Great Basaltic district of India," by J. G. Malcolmson, Esq., F. 

 G. S., of the Madras Medical Establishment. 



■ Dec. 16, 1837. — Mr. Malcolmson's paper on the eastern portion of 

 ^e Great Basaltic district of India, begun on the 15th of November, 

 Jw^as concluded. 



The principal objects of this paper are to describe the eastern boun- 

 dary of the great basaltic formation of India, with its associated strati- 

 fied deposits, and to arrive at a proximate conclusion respecting the 

 age of the basalt. 



Extent of Country. — The region noticed generally in the paper, is 

 included between the 14th and 21st degrees of north latitude, and the 

 75th and 82d degrees of east longitude ; but the districts more particu- 

 larly described, are those watered by the Pennar river (lat. 14o), the 

 pass of the Sichel hills, near Neermul (lat. 19o 18', long. 79^ 33'), and 

 the plains extending from the northern base of that chain to Nagpoor. 



Physical Features of the Country. — The region forms part of the 

 great, elevated plateau which includes all the countries to the south of 

 the Nerbudda (lat. about 22^ N.), and connects the provinces watered 

 by the southern branches of the Ganges with the Deccan. It is tra- 

 versed on the north by the Sichel or Shesha hills, locally called the 

 Neermul range, which extends from the junction of the Wurdah and 

 Godavery rivers (lat. about 18^ 48', long. 80o), till lost in the gradual 

 rise of the country near Lonar (lat. 20^, long. 76° 30'). The principal 

 rivers which traverse the region are the Wurdah, the Godavery, the 

 Kistnah and the Pennar. The first flows north and west of the Sichels, 

 the second south of that chain, till its waters unite with those of the 

 Wurdah, when it takes a south-easterly direction to the Indian ocean. 

 The Kistnah flows nearly W. and E., between the parallels of 16o and 

 17'^; and the Pennar traverses the southern portion of the region 

 (lat. 140 30'). In the part watered by the last river, a marked feature 

 is presented in the horizontal summits of many of the ranges of hills, 

 which appear to have been once connected, though they are now sepa- 

 rated by extensive plains. 



Geological Siructure.—Vne formations consist of granite, gneiss, 

 mica and hornblende slates, trap, argillaceous limestone, red sandstone, 

 with diamond breccia, and tertiary freshwater strata. The granite forms 



