GEOLOGY 
map accompanying this article. All that need be referred to here 
regarding it is that it was a period of sufficient length to permit of 
numerous and important changes in both the organic and the inorganic 
worlds. 
IX. Cretaczous Pertop.—In most other parts of the kingdom, and 
indeed over a much wider area still, a prolonged period of upheaval 
followed the deposition of the Jurassic Rocks, and was accompanied and 
followed by a considerable amount of waste. This denudation, in the 
course of a very long time, ended by reducing the land surface over an 
extensive area in western Europe into a very level plain. Then the 
land once more sank beneath deep water, and the Cretaceous Rocks, 
including the Chalk, were deposited upon this level floor over the whole 
area. The present writer has long maintained that Cumberland partici- 
pated in these changes, as much as other parts of Britain, and that the 
whole district was formerly covered by these interesting rocks, which of 
course have since entirely disappeared, as a consequence of upheaval and 
denudation in times later still. The only vestiges left are the remnants 
of the plain upon which the Cretaceous Rocks once lay, and also by 
here and there a few chalk flints. But the plain is an important feature 
in the scenery of the county. 
For the vast and important biological and physical changes which 
took place between the close of New Red times and the commence- 
ment of the Tertiary Period it is here estimated that a length of 
104,000,000 of years was required. 
X. Posr-CretTacrous Cuances.— Few, if any, of the hills and 
valleys of Cumberland date farther back than Post-Cretaceous times. 
The history of their development will be more fully discussed presently. 
But in the meantime we have to take note of the fact that a very long 
interval of time (which the present writer would roughly estimate at 
93,000,000 of years) separates the close of the Cretaceous Period 
from our own day. Many and very important changes in physical 
geography have taken place in the meantime, while in the organic world 
many generations of plants and animals, quite different from any now 
living, have come into being, and finally disappeared. The very ma- 
terials out of which are formed large parts of great mountain masses, 
like the Alps, the Pyrenees, the Andes, and the Himalayas, had not come 
into existence in the earlier part of the period, and since it commenced 
several oceanic areas and continents have more than once changed places. 
(2) The principal episode with which we are most concerned 
in reviewing this part of the historical geology of Cumberland is con- 
nected with the vast and important development of volcanic action in 
the north-western part of the United Kingdom, and which has left its 
mark in Cumberland as well as in the districts around. ‘Those events 
may be summarized in a few lines: Long prior to the first rough 
shaping of any of the great natural features now existing in Cumberland, 
a series of volcanic vents, ranging in a northerly direction, broke out on 
the western side of the British Isles. This may well have happened 
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