268 Memoir on Indian Earthquakes. [No. 136. 



&c. lead me to the belief that several, if not all of these valleys, were at 

 some former time the receptacles of a series of inland lakes, and the 

 natures of the shells found (principally planorbes and paludinae) seem 

 to indicate that the waters of these lakes had been fresh. In this 

 manner three grand sheets of water, separated by the mountain deflec- 

 tions before alluded to, would appear to have occupied the entire 

 country from Kabul to the Indus, and their basins »may now be distin- 

 guished as the plains which afford sites to the three cities of Kabul, 

 Jellalabad, and Peshawur. 



" The draining of these basins is tranquilly carried on by the Kabul 

 river, which runs along the northern edge of each, conveying their 

 united waters to the Indus : but in former times when more energetic 

 means were necessary, the mountain barriers burst, and the shattered 

 fragments and rolled blocks that now strew the Kyber Pass, bear testi- 

 mony to its once having afforded exit to a mighty rush of waters, 

 while the Gidur-Gulla (or Jackall's neck,) a long defile east of the 

 plains of Peshawur, clearly points out the further course of the torrent 

 towards the bed of the Indus, whence its passage to the ocean was easy 

 and natural." 



The questions in pure geology involved in these remarks I do not 

 concern myself with, but I have quoted them to shew, that indications 

 of powerful disruptive forces prevail throughout the whole of the course 

 of the Earthquake of the 19th February hitherto described, and this 

 point is all that circumstances admit of being established. Of the 

 nature of the rocks composing the mountain masses between Cabool 

 and Jellalabad, I have seen no account. Major Broadfoot states, that 

 the rocks in the immediate vicinity of Jellalabad are gniess, and Sir 

 A. Burnes mentions, that mica slate and granite are also found there. 

 Relative to the rocks in the Kyber Pass, my friend Lieut. Goodwyn of 

 Engineers, writes thus : " The Kyber rocks are of flinty slate, varying in 

 all degrees of hardness from flint to slate. Sometimes the rock is nearly 

 one solid mass, the strata are so slightly defined, and they cannot be sepa- 

 rated with a crow-bar — at other places, a blow of a pickaxe is sufficient 

 to shiver it into fifty little cubes of slate ; a considerable quantity of earth 

 lying between the strata, which falls down in dust. Sir Alexander 

 Burnes says, " The formation is a flinty slate overlying conglomerate, but 



