262 



Proceedings of Societies : 



[Jan. 



That the igneous eruptions occurred at many distinct periods, Capt. 

 Grant showed by sections, in which beds of trap alternate with others 

 of crystalline limestone, calcarious tuff, and a calcarious grit, which 

 sometimes contains angular fragments of basalt; and by beds of very 

 different characters reposing on each other. 



i\mong the phaenomena connected apparently with volcanic action, 

 the author described a number of mounds, varying in diameter from 

 3 to 20 yards, and covered with small tabular plates of sandstone, the 

 lines of fracture radiating, though irregularly, from a centre. In some 

 instances the summits of these little mounds having been removed, 

 a regular circle of stones appeared, inclosing an area of sandstone, 

 the fracture of the stones decidedly radiating as the stones of an arch. 

 In other instances they resembled small hillocks, from the upper part 

 of which the outer coating or tabular plates had generally fallen away, 

 and the whole consisted of a heap of broken masses of rock. 



Tiie author then described what he considers to be a very recent 

 volcanic outburst. It is situated in the nummulitic limestone, near 

 the village of Wage-ke-pudda, and forms a rather high flat basin, or 

 table land of about two square miles, composed of calcarious marl, 

 and flanked by low irregular hills of ironstone and gravel. The 

 sides are broken by fissures, ravines, and hollows, and the bed of the 

 basin is covered with hillocks of loose volcanic scorise of various 

 colours. Within the basin are also several small craters or circular 

 spaces, surrounded imperfectly by walls of columnar, globular, or 

 friable basalt. These basaltic walls, however, he conceives, are of an- 

 terior date to the mounds of scoriae, which he is of opinion cannot be 

 of great antiquity, on account of the facility with which their loose 

 materials are removed by atmospheric agents. Other similar out- 

 bursts were also described. 



The paper concluded with an account of the Great Runn, a district 

 (exclusive of the elevated tracts called " the Bunnee and Islands") 

 of 7000 square miles. This singular region, as already described by 

 Capt. Burns, consists of a sandy flat, dry for the greater part of the 

 year, but during the prevalence of the south-west winds, converted 

 into an inland sea, passable however on camels. Capt. Grant believes 

 that its present oscillating position between land and water, is due to 

 an elevation of the Runn, and not to a change in the level of the seaj 

 and in support of his opinion adduced the alterations both of elevation 

 and depression of land, by the earthquake of 1819. He described also 

 several extraordinary walls of rock, thrown up apparently by volcanic 



