The Pliocene Deposits of Holland. 287 



he gives a section to show wherein his classification of the Dutch 

 strata differs from that of Dr. Lorie. 



The distinction between the divisions adopted by the author 

 comes out more clearly from the consideration of the abundant and 

 characteristic species only, of each of which he gives lists. 



Although the Amstelien beds are more than 400 feet in 

 thickness, they contain a shallow-water fauna, and were deposited 

 in a basin which subsided pari passu with their accumulation. 



In the map an attempt is made to show the limits of the sea of 

 the Anglo-Dutch basin during the various stages of the Pliocene 

 epoch. 



It is suggested that the Chillesford Clay was deposited in an 

 estuary through which the Ehine discharged into the North Sea, its 

 presence in the western portion of the Pliocene basin being caused 

 by the elevation of Holland after the deposition of the Amsteline 

 and a subsidence in Suffolk, which carried the Chillesford Beds over 

 an area which was not covered by the Norwich Crag sea. 



No equivalents of the Weybourn Crag or of the Cromer beds 

 (Forest Bed series) have been found in the Dutch borings. These 

 are to be referred to the Pliocene, as pointed out by Mr. Reid, but 

 possibly some of the unfossiliferous pebbly gravels of Norfolk and 

 Suffolk may be Pleistocene. 



The Weybourn Crag marks a re-invasion of East Anglia by the 

 sea ; but previously to the deposition of the Cromer beds the southern 

 margin of the Pliocene gulf had again retreated to the north, and an 

 estuary, similar to that of the Chillesford Clay but situated farther 

 east, received the waters of the Ehine, which brought down the 

 drifted remains of mammalia and some southern mollusca. 



The newest portion of the Cromer deposits is of an Arctic 

 character, and seems to show that no great interval separated the 

 Pliocene and the Pleistocene periods. 



A second subsidence of the Dutch area took place in Pleistocene 

 times ; the Glacial and post-Glacial beds being 600 feet thick under 

 Amsterdam. No Till or Contorted Drift similar to the deposits 

 occurring in East Anglia and in the district north-east of the Zuyder 

 Zee has been met with in these borings. The glaciation of Holland 

 proceeded from the Baltic and not from Norway, and the Baltic ice 

 does not seem to have reached the Dutch coast ; still less could it 

 have travelled thence in the direction of East Anglia. 



The two prominent physical features of the Pliocene period were 

 the Rhine and the basin of the North Sea. The hypothesis of a 

 permanent basin with shifting shore-lines, in contiguity to which 

 the shallow-water deposits of the Upper Crag were deposited, seems 

 to agree with all the facts of the case, and to throw light on the 

 geographical conditions of the Pliocene epoch. 



