GUERNSEY CLAYS. 217 



flints were found. Perhaps this special deposit belongs to a 

 different period from those on the table-land, and may have 

 been formed in a different manner ; being on a lower level it 

 is more easy to imagine streams flowing over the higher parts 

 of Guernsey, then perhaps much larger than now, and depo- 

 siting this clay in a sheltered area of the sea, or large pond. 

 Then the previous deposition of the sand has to be accounted 

 for. I show a sample of the sandy material, and also of the 

 loam, deposited by our present streams, which can be com- 



Eared with the Vrangue sand, and the clay and loam of the 

 rickfields. 



When last visiting the clay-pit behind Nant's farm at 

 St. Andrew's, from which all the good surface material has 

 been removed, I was much struck by a process now going on 

 there. The rock, as usual, is in a very decomposed state, 

 having the appearance of hard plaster on the exposed face, 

 but on applying a knife it can easily be cut away. Some of 

 the decaying veins yet retaining their original shape and 

 position have changed into clay of varying colours, some blue, 

 some yellow. The rainfall acting on the material thus exposed 

 and on masses perhaps designedly thrown down, has formed 

 in the lower corner of the pit a deposit having much the same 

 colour and surface appearance as our ordinary clay. But it is 

 only the thinnest surface which is clay, beneath, particles of 

 various sizes are mixed irregularly. 



The idea occurred whether all our deposited clay could 

 have been formed in a somewhat similar manner. A very 

 lengthened period would be required to enable the material to 

 be accumulated to its present depth slowly as the result of the 

 flow of the present rainfall. The clay would have to lie in 

 shallow hollows with banks around them ; such conditions 

 cannot now be traced. Vegetation would prevent such a 

 process going on, so that it could only take place if the surface 

 were bare, which would imply a very severe climate, and 

 would agree with the fact that no signs of animal or vegetable 

 life have been discovered in the clays ; then again, the stones 

 included in it would be local stones, not having been much 

 rolled or carried far they would still be angular, and so, many 

 of the difficulties of the case would be met. 



We have at present scarcely any facts collected bearing 

 upon the age of the formation. It is covered by falls from the 

 higher part of the cliff at Fermain Bay (north side), &c, and 

 members will remember that a deposit of yellow clay was 

 found 20 feet below the present surface in sinking a well at 

 the Truchot, and that it was followed by 2 feet of peaty mould. 



