A HISTORY OF NORFOLK 



further slips. The beach deposits are nowhere very thick below the cliffs, 

 and at various places they are now and again cleared off after heavy gales 

 in some places and heaped up in others. 



The old church of Eccles-next-the-Sea, rendered famous by the 

 descriptions of Lyell, must originally have been built in an alluvial 

 valley separated from the sea ; it gradually lost the protection of higher 

 ground, and was in 1839 surrounded by blown sand. Since that date 

 the blown sand shifted inland and the round church tower for many 

 years stood lonely on the foreshore several yards from high-water mark. 

 In January, 1895, the tower was destroyed during a violent storm. 



CONCLUSION 



These evidences of destruction in one place and of accumulation in 

 another are but continuations of geological history which tells of constant 

 change. 



The strata of which we have evidence in Norfolk present to us all 

 conditions from that of deep sea to shallow sea, and all climates from that 

 of tropical to arctic. 



The present inland features are due mainly to the influence of rain 

 and rivers subsequent to the great Ice Age. The melting of the ice 

 which formed the Chalky Boulder Clay doubtless produced torrential 

 streams which marked out some of the main lines of drainage, and the 

 ordinary action of rivers carried on the work during the succeeding 

 milder epoch which links on to the present. The land stood higher and 

 extended much further, and the rivers had longer courses and greater 

 falls. 



The passing away of the icy conditions left a great plain whose 

 surface was formed partly of gravel and sand, partly of loam and Boulder 

 Clay, and partly of Chalk and older strata. On such a varied platform 

 the action of subaerial forces would vary, as rain sinks into porous strata, 

 but directly erodes impervious deposits like clay. Beneath sheets of 

 gravel overlying clay, the waters collect and issue where they can along 

 the valleys. Subterranean watercourses no doubt exist beneath sheets of 

 sand and gravel, as is evident from the permanency of certain springs. 

 They flow along definite courses marked out on the floor of clay 

 and must cause some subterranean erosion. Their courses may be 

 indicated by slight sinking of the ground, and eventually patches and 

 outliers of gravel become separated from the main mass. In this way 

 may we account for some of the many gravel hills scattered over the 

 clayey and marly regions, as near Holt. 



Evidence of man's existence during the formation of some of the 

 earlier valley-deposits has been proved by the occurrence of Paleolithic 

 implements. Many and great changes have taken place since then ; and 

 we can only surmise that the present features had been mainly formed 

 when his Neolithic and other pre-historic successors occupied the 

 country. 



In some counties where there are broad alternate bands of impervious 



28 



