CHANGES IN THE RELATIVE LEVEL OF SEA AND 

 LAND ROUND GUERNSEY. 



A Paper read before the Society by Mr* G. T. Derrick, on 

 May Uth, 1883. 



Changes in the relative level of sea and land have occurred 

 within historic times, and even in our own day in various parts 

 of the world ; such changes are among the well-known results 

 of volcanic agency, but in countries considered to be outside 

 volcanic districts, phenomena can be observed which seem to 

 prove that such movements are pretty generally distributed. 

 These modern movements cannot be compared in grandeur to 

 to those which took place in former geological periods which 

 gave rise to the vast series of sedimentary rocks ; they have 

 caused local alterations, but are not sufficient to prevent it 

 being true, that the aspect of the various continents has not 

 substantially varied within historic times. 



The attention of the members of the Guernsey Society of 

 Natural Science has from time to time been turned to certain 

 districts of our own island, which appear to prove that it has 

 undergone changes of level. 



The existence of peat under the present sea-beach has been 

 known since 1757; the beds extend along the low shores of 

 both the eastern and western coasts. It has been dug into in 

 the Town and at St. Sampson's harbours, it can be observed at 



