310 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



gravels, but Lampliigh does not consider them as interglacial. He 

 regards the Holderness gravels as possibly marine, but contempo- 

 raneous with the continuous formation of bowlder clay in other 

 parts of the area, during an oscillation of the ice edge ; this sugges- 

 tion was considered by C. Reid to be negatived by the fauna. 



In Durham C. T. Trechmann (72) found a somewhat similar se- 

 quence — lower shelly bowlder clay with Scandinavian bowlders, 

 overlain in places (especially in cavities in magnesian limestone) by 

 current bedded shelly sands, probably marine, and this in turn by 

 Cheviot bowlder clay with Scottish and Cumberland erratics, prob- 

 ably equivalent to the Hessle clay. In Northumberland Doctor 

 Woolacott (73) found only one bowlder clsij, but underlying it 

 north of the Wansbeck he found a coarse gravel which may represent 

 the gravel beds of the Durham coast. 



Near Hartlepool the Cheviot clay is overlain by a gravelly bed 

 extending fairly continuously at an altitude of 60 feet; Doctor 

 Woolacott regards this as the continuation of a raised beach which 

 he discovered resting on the bowlder clay from Seaham to Castle- 

 Eden-Dene. The beach decreases in height both north and south 

 from 150 feet at Cleadon and Fulwell to 50 feet at Seaham and 60 

 feet at Castle-Eden-Dene, while a raised beach at Saltburn lies at 

 30 feet. 



Eeturning to East Anglia we find that the contorted drift breaks 

 up into isolated mounds and ridges as it passes southward, but the 

 marine sands of Cromer and Yarmouth merge into S. V. Wood's 

 widespread "middle glacial" and the chalky bowlder clay forms a 

 widespread sheet. No traces of temperate deposits have been found 

 in the "middle glacial." It seems that the great subsidence in Hol- 

 land during the early Quaternary was sufficient to deflect the Scan- 

 dinavian ice from East Anglia farther eastward. In this way would 

 be explained the total absence of a bowlder clay underlying the 

 chalky bowlder clay in central England, a fact otherwise incompre- 

 hensible. And, further, the deep river valleys of Norfolk and Suf- 

 folk, which extend below sea level, and are post North Sea drift, 

 but pre chalky bowlder clay, are possibly subglacial fjords (74). 



The archeological horizon of the chalky bowlder clay is fixed as 

 pre-Acheulian by the well-known section at Hoxne (75) which gives 

 the section — 



4. Loam and gravel with Acheulian implements and widespread fauna 



and flora. 

 3. Blacli loam witli numerous arctic plants ; 13 feet. 

 2. Lignite and lacustrine clay with temperate plants and moUusca ; no 



arctic plants. 

 1. Chalky bowlder clay and glacial sand. 



From this section it appears that not only is the chalky bowlder 

 clay older than the Acheulian culture, but is separated from it by a 



