It is possible, however, that this violent action may not have — 
existed during the whole formation of the cone, and if so, the 
center may be older than the surface indicates. I believe' the 
Alps at this point are considered to have been elevated in the 
position as to show that at that epoch the valley was already 
in existence, and that it had nearly its present size. It must 
clusions seem highly probable: 
BS Th i 
e tranquil period of the lower cone was synchronous . 
with the period of peat formation in the valley of the Somme, 
and their age would appear to be somewhere from 4,000 to 6,000 
years, 
2. The violent water action of the upper cone was cotempo- 
raneous with the corresponding activity of the Sommein the 
gravel period. = : 
3. During this period, the water-flow was enormous, the 
gravel accretion extremely rapid, and the time occupied by the 
deposits correspondingly short. 
; 
