7 2 



Corrie-glaciers hardly creep beyond the recesses in which they 

 are formed and do not reach even the nearest valley. — 6. 



After a glacier has passed over soft rocks like chalk, or oolite, 

 the striae that it caused must rapidly disappear upon the melting of 

 the ice. And, on a steep coast, like that of Dorset or of Hampshire, 

 morainic matter must be pushed into the sea by the glacier itself. 

 Thus all the ordinary evidence of an inglaciation may have gone 

 thousands of years ago, and proofs only of the deglaciation may 

 remain, such as a few scattered stones rubbed or scratched, and a 

 little unstratified drift that can have been neither marine nor 

 fluviatile ; though sometimes there may be found confused heaps of 

 sand and gravel, suggesting perhaps the flood of a veritable Ganges 

 rather than their true cause, the rapid and tumultuous melting of 

 large masses of ice and snow. 



Drift presents itself in seven forms, marine action being 

 excluded, (i) alluvium, (2) loam, (3) river-gravel, (4) glacial loam, 

 (5) glacial boulder-clay, (6) glacial-gravel, (7) clay-with-flints. — 7. 



The clay-with-flints is essentially a remanie deposit derived from 

 eocene, or other strata, above the chalk. The invariable occurrence 

 in it of considerable quantities of rounded quartz sand shows that it 

 cannot have arisen from solution of the chalk. It usually contains, 

 also, pebbles undoubtedly derived from eocene strata, as well as 

 masses of Savsen stone. Its distribution is singularly partial, and it 

 is confined, though not invariably, to districts where outliers of 

 tertiary strata still occur. Water-sheds and isolated hills of chalk, 

 on the other hand, have a capping of a few feet of unworn flints, 

 apparently derived from the chalk by solution. Whenever the con- 

 ditions permitted running water to obtain any power, at a period 

 when chalk was frozen and impervious to a considerable depth, 

 the loose flints were mostly swept away to form coombe rock or 

 valley gravel, which is found largely in Sussex, scantily in Hants, 

 and not at all in Dorset (?) — 8. 



It was formerly believed, and was taught by Prof. Geikie 

 himself that the glacial phenomena of this country, such as the 

 "contorted drift" of Cromer, and the presence of marine shells 

 many hundred feet above the sea, were due to the grounding of 

 icebergs, at a time when the land was submerged. But the present 

 opinion, with which Prof. Geikie now agrees, is that they are the 

 result of the actual passage over those districts of the great 

 Scandinavian glacier. — 9. 



Even the very shells had been ploughed up from the sea 

 bottom, carried over the ground and deposited on mountain slopes 

 at an altitude of over 500 feet. 



The whole of northern Europe was buried under a continuous 

 ice-sheet, 770,000 square miles in extent. Its southern edge lay to 

 the south of Ireland, whence it passed along the line of the Bristol 

 Channel across the south of England, keeping to the north of the 

 valley of the Thames. Its thickness, in the northern part of 



6 — Geikie. 

 7 — Monckton. Geol. Field, p. 42. 

 8— Geikie, 1896. Glac. Mag., v., 68. 

 9— Glac. Mag., v., 49. 



