1866.] SEELEY DKIFT OF THE FENLAND. 479 



pies of nearly every rock in the north of England, especially those of 

 the Yorkshire coast (Kelloway rock, the sandstones, limestones, and 

 shales) and the Eed Eock of Hunstanton. Though Carboniferous and 

 older Palaeozoic rocks and fossils abound, and trap and plutonic rocks 

 are not rare, they are rounded boulders, the flints are often un- 

 broken, and there is a rough stratification. But the most important 

 fact about the deposit is, that descending on the east side towards 

 Pulbourn it becomes Boulder- clay *. 



Part II. Theoretical. 

 [Abstract.] 



In this part of the paper the author endeavours, from . internal 

 and other evidence of the deposits, to indicate their origin and their 

 relative age. 



1. Brown- or Boulder- Clay. — He concludes that, prior to the de- 

 pression of the country, when the Boulder- clay was formed, the Wash 

 had no existence, and that the Cretaceous barrier between Waynfleet 

 and Hunstanton was not broken through. He inclines to believe that 

 this Boulder-clay was deposited by drifting ice, on the hill- tops &c., 

 much where now found, during a period of change so slow that the 

 fauna was able to migrate and follow it. There is no evidence in 

 the deposit of glacier-action ; but it contains rock-specimens such 

 as are now found in Yorkshire strata. It appears to be the oldest 

 drift-deposit of the district ; and the author correlates it with the 

 Brown Clay or Till of the Norfolk coast. 



2. Coarse Gravel. — This is chiefly found capping or bordering the 

 Boulder-clay ; and the author infers, from its composition and rela- 

 tions, that it has resulted from the mud having been washed away from 

 the Boulder- clay during the period when the country was rising from 

 the sea. It is chiefly found on hills, and is of the age of the Con- 

 torted Drift of the Norfolk coast. 



3. Deposits neiver than the Fine Gravel of the Plains. — These are, 

 first, a Peat, anterior in date to the formation of Whittlesea Meer. 

 Under this is a Marine Clay with remains of Walrus, Seal, &c., 

 Ostrea, Cardium, Scrohicularia. It is named by the workmen 

 " buttery clay." Under this is an older Peat containing extinct 

 mammals, such as Bos frontosus, Bos primigenius, Cervus megaceros. 

 Among the other species are Cams lupus, Castor europceus, Sus 

 scrofa, Cervus elaphus, Cei'vus capreolus, Lutra vulgaris, Ursus 

 arctos, &c. Among the fossils have been found teeth of Rhinoceros 

 and Hippopotamus, probably derived from the gravel. The fauna 

 of these beds is very similar to that of the newest gravel. They 

 correspond to the peat- and sand-beds which fill the valley of the 

 Mundesley Section. 



* In a supplement to a Lecture on the Fens and their Fossils, Professor 

 Sedgwick (in 1862) gave a brief but clear account of these drift-deposits. I have 

 used Professor Sedgwick's names as having the sanction of half a century of 

 teaching, and have freely availed myself of the Professor's experience as given 

 in his Lectures. 



