130 
THE GEOLOGIST. 
I have pointed ovit also the capping of brick-eai-th and ossiferous 
marl on the West Cliff, to show to the inexperienced student that the 
juxta-position of strata is no proof of relationship ; but that beds of 
earth lying together in proximity may be far removed from each in 
the dates of their formation, and indeed may belong to very different 
causes and events. In this case, as in others, the fossils are the true 
medals of the past ; and here they teach us that while the cretaceous 
rocks exhibit from top to bottom the dominion of the sea in a remoter 
age, the marls and brick-earth were not deposited until after the 
marine sediments of the cretaceous rocks had been first raised into 
diy land, and then denuded or worn away — sliced off — to the extent 
of at least a thousand feet in vertical height ; and that while the 
former group belongs to the mid-period of the earth's history, the 
latter is of recent date, but just preceding if not coeval with the first 
appearance of man, for the fossils it contains are those of the great 
terrestrial beasts, with the remains of which in other places the flint- 
implements and other traces of his works are found. Let us then 
briefly tell the story of those events — it has been often told before, 
but no matter, everyone has not heai'd it, and even those who have 
delight to dwell upon it — and those ancient physical conditions with 
which the geological history of the gault is associated. The con- 
secutive chain of events is as readily conceived as it is plainly to be 
traced. 
First, the old dry land of oolitic rock, with its thick umbrageous 
forests, and its enormous river pouring into a delta — rivalling that of 
the Ganges — sediments that formed the Wealden beds, sank gradually 
below the level of the sea, and the great accumulation of the lower 
greensand took place. The depression of the land still going on, the 
finer deposit of mud reached higher on the sinking coast, and en- 
croaching on the sands as they sank deeper and deeper beneath the 
waves, the Greensand became covered by the Gault. The upper 
greensand would seem to indicate a temporary elevation, or at least 
a shoaling of the water. Again, a further sinking carried the once 
dry ground to the depths of the ocean, where in the quietest calm of 
the abyss lived those little Foraminifers, whose tiny shells chiefly 
form the mountain mass of chalk. 
The Portland-stone, on which rest the Wealden beds (of fresh- 
