GEOLOGY 
NEOZOIC PERIOD 
Post-Piiocene Deposits: Peat, Alluvium, Raised Beaches, and the 
various deposits of Glacial origin. 
Unconformity. 
Dykes and Mineral Veins of Tertiary age. 
Unconformity. 
‘TERTIARY CRETACEOUs rocks represented by scattered Chalk flints, etc. 
Great Unconformity. 
Lias, 
Ruaztic Rocks. 
New Rep Rocks: 
B. Keuper Marl. 
St. Bees Sandstone. 
Bunter Marl. 
A. Magnesian Limestone and Plant Beds. 
Penrith Sandstone and the Brockrams. 
Great Unconformity. 
VI. Tue New Rep Serizes.—(a) After the protracted period of 
subsidence and deposition, during which the Carboniferous Rocks were 
formed—a period which may well have extended over very many millions 
of years—the downward movement which prevailed during that period 
came to an end, and a movement in the opposite direction began. Just 
as in previous times the old Silurian sediments, after a protracted period 
of subsidence, were gradually crumpled and folded by earth creep, so 
that they were slowly squeezed up into mountain ranges and gradually 
wasted away ; so it was with the Carboniferous sediments at the period 
now under consideration. The evidence clearly points to the fact that 
part, at least, of the area which now forms the Lake district was one of 
the chief centres of upheavals at this early period. So, too, with part 
of the area of the southern uplands of Scotland. The old Carboniferous 
sediments, after being carried downward by subsidence miles below the 
sea level, and there gradually folded, were slowly upheaved, folded by 
lateral thrusts, and fractured and faulted as they arose. As the masses 
slowly and quietly emerged and were elevated into uplands, atmospheric 
waste favoured the removal of the rock material, just as it had done with 
the predecessors of these rocks on the same spot in times previous. And 
just as in former times the rate of upheaval in the earlier stages of 
movement kept slightly ahead of the rate of waste, so the newly-exposed 
land gradually increased in elevation, and Cumberland found itself farther 
and farther removed from the sea, and therefore from the main source of 
rain. Hence, after a long transition period, desert conditions again set 
in. The change of conditions was a very gradual one,'so that many 
wadies were gradually shaped by the streams before the period when the 
rainfall reached its minimum. In Jater times these old valleys, or wadies, 
were gradually filled up by the waste of the rocks of which their sides 
were formed. It may be repeated here that, under continental condi- 
tions, where the air generally contains a smaller percentage of aqueous 
vapour than usual, the sun’s heat exercises a much more powerful influ- 
ence by day, because the temperature of its rays near the earth has not 
been lowered by a passage through the moist aerial screen. In like 
31 
