380 THE DEPOSITS. 



area of the present land surface. It is, however, different 

 with the post-Mousterian glaciation, the extent we are able to 

 limit by the deposits of inland " Head." 



One example of the deposit will suffice, and I chose one 

 of the St. Saviour's exposures because in that parish there are 

 better and more characteristic deposits than I have found 

 elsewhere. 



By means of the diagram No. 9 provided it will be seen 

 that the road near Les Hougues mill forms a kind of ridge of 

 land with valleys or slopes on each side. If we suppose the island 

 to be covered by ice we can see that there would be a thrust 

 from the higher land along the ridge. The ice would, in part, 

 pass down the Choffins valley and in part over the north edge 

 of the ridge ; but part would continue along the top of the 

 ridge until it accumulated on the broader part where the mill 

 stands. The thrust would then cause a movement towards 

 Mont Saint, down the slope of which hill it would push the 

 detritus it was detaching from the mill plateau. 



The section (Diagram No. 8) shows this detritus arranged 

 on the slope with its stones so placed that their inclination is that 

 of the slope. This deposit of angular stones, derived from the 

 rocks of the plateau, covers the whole slope and is visible on the 

 road cuttings. It is only a small portion remaining of a pre- 

 vious extensive moraine, but is much obscured by the numerous 

 cuttings through it by the roads and their junctions. 



This deposit contains some of the remains of the boulder 

 clay which resulted from the previous glaciation and has been 

 covered by the upper clay which, although much denuded 

 can be found under the soil of the plateau and on the hill. 



Here then we have the probable limit of the second 

 glacial cap. This is at an elevation of about 100 feet and, 

 therefore, if it is accepted as the margin of the ice, would 

 show that the lower slopes of the island were free. 



Stage 3.— Part 2. 



GLACIAL DEPOSITS. 



THE CLAYS, THEIR NATURE AND MEANING. 



There are deposits of clay of practically all stages of 



the period under discussion, and as some are of the nature 



of passage beds and have been sufficiently treated of already 



it will not be necessary for me to give more than one example 



in order to differentiate them from the more important 



deposits. 



The clays found intermixed with rubble in the above 

 beds are derived from decomposing rock at a higher level, and 



