410 A. B. Wynne— The Salt Range. 



A similar hint is offered by the fact that the glacial drift of the 

 west of England, and of parts of Ireland, contains mollusca of a more 

 southern aspect than that of the east side of the former. For it 

 allows us to suppose a milder climate existing on the west all 

 through the period of cold, and thus affording a retreat for forms 

 which might otherwise have perished. 



Thus, although the question of the probability of mammalian and 

 other remains in the glacial drift of Britain without the intervention 

 of warm intervals, cannot be definitely settled until the preliminary 

 one of the extent of the land of the Glacial period is disposed of, 

 enough has been brought forward to show how easily it might 

 happen under certain conditions. 



Finally, it may be affirmed that the evidence that the intercalated 

 sands and gravels were formed during a mild interglacial period is 

 in no single case conclusive; that while they are not the sort of 

 deposits to be, a priori, expected as the result of a mild interval, 

 they are just such as would naturally result from the action of sub- 

 glacial streams, the oscillations in the extent of the ice causing the 

 overlapping of glacial and aqueous deposits, and the work of the 

 ice itself; and that a gradually, but intermittently, advancing ice- 

 sheet, or glacier, could not avoid overwhelming and burying in its 

 own debris masses of vegetation, while the latter, closely following 

 the retreating ice, and growing on its accumulations, could not fail 

 now and again to be buried beneath the deposits of some temporary 

 advance of the same. 



And since, looking to the present, the work actually done beneath 

 an ice-sheet or glacier — especially in those parts remote from its 

 lower margin — is still shrouded in mystery, it seems rash to assign 

 every bed which does not conform to our usual idea of the work of 

 the ice to an interglacial epoch. 



V. — Recent Geological Investigations in the Salt Eange. 



By A. B. Wynne, F.G.S. 



ri^HE Geological Survey of India Eecords, vol. xxiv. part 1, 1890, 

 J. only came to hand to-day, enabling me to see Mr. Middlemiss's 

 late paper on the Salt Eange. 



It appears to be one of the many charms and mysteries of Salt 

 Eange geology that it affords fresh discoveries to each successive 

 explorer ; hence, possibly, something yet remains to reward the 

 next pilgrim who may have the chance to criticize Mr. Middlemiss's 

 conclusions, — let us hope instructively. 



The paper at present referred to possesses a great deal of interest, 

 and has much importance with regard to structural geology. I trust 

 it may receive worthy notice under light more modern than that in 

 which my Salt Eange work was carried out more than twenty years 

 ago, without the advantage or disadvantage of a tendency to form 

 foregone opinions about the views of others before I reached the 

 ground. Perhaps I may also remind readers that when I was 

 thus engaged, the doctrines of inversion, earth-thrusts of several 



