380 



SECTIONAL TRANSACTIONS.— H. 



(Only broad terms in the industries and stratigraphy are introduced.) 



Horizon. 

 Newer Drift (Boulder Clay, &c.) 

 Brickearths, Valley deposits, &c. 

 Upper Chalky Boulder Clay, Con- 

 torted Brickearths, &c. 

 Sands, Gravels and Brickearths. 



Chalky-Jurassic and Chalky-Neooo- 

 mian Boulder Clay (= Lower Chalky 

 B.C.) 



Sands and Gravels .... 



Scandinavian Drift of Durham, 

 Yorks, Norfolk, &c. (Norwich 

 Brickearth). 



Cromer Forest Bed 



Red, Norwich, 

 Crags. 



Weybourne, &c.. 



Climate. 

 Glacial . 

 ?Warm . 

 Glacial 



?Warm . 



Glacial . 



?Warm Molluscan 

 fauna very like 

 present day, but 

 possibly derived. 



Glacial . 



Warm in the main. 

 Fauna in part 

 derived. 



Earlier crag deposits. 

 Warm, later cold. 



Industry. 

 Magdalenian. 

 Aurignacian. 

 Mousterian. 



Acheulean and de- 

 veloped Chellean. 

 ? 



Early Chellean. 



Pre-Chellean. 



The serious problem presented by the above table is that, if we accept the Cromer 

 Forest Bed implements as Early Chellean, the Chellean industry must straddle a 

 powerful glacial episode, and presumably be of long duration. When I pointed out 

 this difficulty to the Abbe Breuil in numerous discussions last summer he was very 

 loth to admit any such straddling, and preferred to be non-committal regarding the 

 dating of the Cromer Forest Bed implements. We agreed that an impasse had been 

 reached and that we must await further evidence. Now the belief seems to be general 

 that the Mousterian on the Continent belongs dominantly to the Riss-Wiirm inter- 

 glacial episode (the Levallois industries I and II being, according to the Abbe Breuil, 

 late Mindel-Riss, and the Levallois III being Riss-Wiirm) and that the Acheulean 

 and developed Chellean belong to the Mindel-Riss interglacial episode. Granting 

 this to be the case, I leave my archaeological friends, if they insist on Alpine correla- 

 tions, to correlate the Giinz (or first East-Alpine) glaciation with either of the two 

 earlier glaciations as they please. As compared with early Alpine glaciations there 

 is apparently one cold period too many in the British area. The case at present is 

 worse than that of the mythical Irishman's waistcoat, which had one button too 

 many at the top and one buttonhole too many at the bottom, for here we have one 

 button too many in the middle. 



At this stage a note is perhaps desirable on the Scandinavian Drift, lest it should 

 be thought that this deposit is due to a minor fluctuation of an ice-sheet. The 

 Scandinavian Drift is found in Durham, Yorkshire and East Anglia, being termed the 

 ' Norwich Brickearth ' in the last-named region. The Cromer Till and Contorted 

 Drift, which were also formerly included in this group of deposits, are at the moment 

 regarded by different geologists as due to one of three different ice-advances (those 

 of the Scandinavian Drift, the Great (Chalky) Boulder Clay and the Newer Drift) ; 

 they may therefore be disregarded for the time being. 



The Norwich Brickearth is underlain near Lowestoft by a ' warm ' Forest Bed 

 which has always been accepted, from the evidence of its fauna and flora, as equivalent 

 to the Cromer Forest Bed. 



The peculiar lithology and characteristic boulders of the Scandinavian Drift 

 differentiate it from the later boulder clays. It has the appearance of a much more 

 ancient deposit, for it is frequently decalcified and weathered : moreover, it is eroded 

 until its surface has become hummocky or so that the deposit now exists only as 

 outliers. The mature, open valley-systems of Norfolk and Suffolk are cut through a 

 widespread sheet of it, but the Chalky Boulder Clay of the succeeding glaciation 

 wraps over from the plateau on to the valley flanks and floors. The valley-systems 

 may thus be regarded as interglacial, for the Scandinavian ice-advance was followed 



