32 R. D. Oldham — Facetted Pebbles from the Punjab. 



at Airdrie in Scotland carried eastward from the bottom of the 

 CJjde ; and those in Caithness from Moray Firth, were among 

 examples adduced in proof of this principle. The improbability of a 

 great submergence not leaving corresponding deposits in other parts of 

 England was dwelt upon. 



It was also held that there was insufficient evidence of more than 

 one advance in the ice-sheet, although halts occurred in its retreat. 

 The idea of successive elevations and submergences with advances and 

 retreats of the ice was disputed, and the author held that much of the 

 supposed interglaeial drift was due to snbglacial water from the 

 melting ice. 



The last portion of the paper discussed the distribution of boulders, 

 gravels, and clays south of the glacial area. Much the greater part of 

 England was believed to have been uncovered by land-ice. The drift 

 deposits in this area were shown to be the result in part of great 

 freshwater streams issuing from the melting ice-sheet, and in part of 

 marine currents bearing icebergs during a submergence of some 450 

 feet. The supposed glacial drift about Birmingham, and the concen- 

 tration of boulders at Wolverhampton, were regarded as due to the 

 former agent ; while the deposits at Cromer and the distribution of 

 Lincolnshire chalk across southern England was due to the latter. 

 The supposed esker at Hunstanton was believed to be simply a sea-beach, 

 and the London drift deposits to be of aqueous origin. Thus the rival 

 theories of floating icebergs and of land glaciers were both true, the 

 one for middle and southern England, the other for Scotland, Wales, 

 and the north of England ; and the line of demarcation was fixed by 

 great terminal moraines. The paper closed with an acknowledgment 

 of indebtedness to the many geologists of England and Ireland, who 

 had uniformly rendered generous assistance during the above investiga- 

 tion. 



VII. — Note on the Facetted Pebbles from the Olive Group of 

 THE Salt Eange, Punjab, India. 



By R. D. Oldham, A.E.S.M., 

 of the Geological Survey of India. 

 T the last meeting of the British Association certain facetted 

 pebbles derived from the Olive group of the Salt Eange, and 

 presumably of glacial origin, were exhibited and commented on.^ 

 Some doubt appears to have been expressed as to their being due to 

 glacial action. The following notes on these pebbles and the bed 

 they were derived from may prove of interest. 



The boulder bed of the Olive group in the Salt Eange consists of 

 a fine-grained, thin-bedded, shaly matrix, usually of that shade of 

 green from which the name of the group is derived ; through this 

 are scattered blocks of hard crystalline and metamorphic rock, of 

 all sizes, from an inch or less to several feet in diameter. They are 

 too abundant for their occurrence to be explained by the action of 

 drift wood, nor is there any sign of cabonaceous matter in the bed ; 

 there is no indication of volcanic action, and, as many of the frag- 

 ments must have travelled scores, if not hundreds of miles, we are 

 1 See Geol. Mag. 1886, Decade III. Vol. III. pp. 492, 494, 574. 



