part 3] l(ess, etc. of the durham coast. 1 85 



beds. The evidence from the contained organic remains lends, 

 on the whole, support to this conclusion ; but it also tends to show- 

 that the deposit is a mixed one, and that some pre-Cromerian beds 

 were also caught up and carried along with it. 



Many Continental geologists regard the Oomerian beds as 

 belonging to the first Interglacial Period of Northern Europe ; 

 Dr. E. Hang refers them to the top of the Lower Quaternary. 



The greatest extension of the Scandinavian ice-sheet seems to 

 have taken place after the first Interglacial episode of Scandinavia; 

 and it was in all probability the fringe of this ice-sheet that reached 

 the Durham coast, and originated the peculiar deposits at present 

 under description. 



Mr. Gr. W. Lamplugh has stated his opinion 1 that the material 

 on the Durham coast which I called ' Scandinavian Drift ' is 

 undoubtedly the equivalent of the Basement-Clay of Holderness. 

 I am disposed, in general, to agree with this conclusion ; but I may 

 point out that I do not regard this correlation as absolutely certain, 

 as I think that the Durham deposit may be earlier than the visible 

 so-called ' Basement- Beds ' in Holderness. The latter contain 

 Scandinavian boulders mixed up with English and Scottish erratics; 

 whereas in the Durham Scandinavian clay I have repeatedly 

 searched, but without success, for English rocks other than the 

 quite local Permian material. It is a 'pure culture 1 of Norwegian 

 stones, no trace of Cheviot, Carboniferous Limestone, nor Whin 

 Sill is to be found in it. 



The Basement-Clay in South Yorkshire and in the Eastern 

 counties south of Yorkshire seems, in its higher levels at any rate, 

 to have been disturbed by the later local ice. Beds containing 

 solely Scandinavian stones may occur in buried and unseen posi- 

 tions resting on the bed-rock in Holderness; but, so far as 1 am 

 aware, or have myself seen, they are nowhere exposed at the 

 surface. 



The question whether the Scandinavian erratics in England were 

 carried directly from their source of origin to their present site 

 by an ice-sheet, or were rafted by melting icebergs into the North 

 Sea and subsequently picked up by local glaciers which passed out 

 into the North Sea and carried inland again, is one that still from 

 time to time comes up for discussion in this country. It seems 

 to be a relic of the old ■ drift theory,' and should, if possible, be 

 finally decided. At the same time, it must be admitted that 

 the mingling of the Scandinavian, English, and Scottish rocks in 

 the Basement shelly clays in Holderness appears to lend support 

 to the iceberg-drift theory. 



In my opinion, this theory has tended to obscure the true 

 history of the early invasion of the east coast of England by the 

 Scandinavian ice-sheet, and it is hoped that the evidence now 

 brought forward will finally dispel the idea that the Scandinavian 

 erratics in England were drifted hither by icebergs. 



1 Q. J. G. S. vol. lxxi (1915) p. 80. 

 Q. J. G. S. No. 299. i> 



