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THE PHYSICAL GEOGRAPHY OF THE PAST. 
A CHAPTER IN THE PHYSICAL GEOGRAPHY 
OF THE PAST. 
PRESIDENTIAL ADDRESS 
GIVEN TO THE BURTON-ON-TRENT NATURAL HISTORY 
AND ARCHAEOLOGICAL SOCIETY. 
BY HORACE T. BROWN, F.G.S., F.I.C., F.C.S. 
(Concluded from parje 287.) 
Thus we see all the evidence is in favour of the compara¬ 
tive stability of the land areas in Carboniferous times, and 
the gradual bending down of the floor upon which the 
sediment was deposited. 
I have now given you a condensed account of the leading 
facts connected with the laying down of the materials forming 
the Carboniferous Rocks of this part of Europe, and have 
shown you how the record of the conditions prevailing during 
their deposition is written in indelible characters in the 
rocks themselves. 
My sketch would, however, be incomplete if it did not 
include some reference to the agencies which have upheaved 
these once horizontal strata, and have brought them into the 
elevated position which they now occupy in the hill country 
of Northern England. 
We have already seen how, in the Pennine Range of hills, 
the rocks composing them are now arranged in a series of 
folds or corrugations. With a difference in degree only we 
always find this tendency to ridge and furrow arrangement 
in all strata which have been in any way disturbed, but it 
attains a maximum of development in mountainous districts, 
where the disturbing forces have been great; the folds, in 
such cases, assuming great height, and bending on themselves 
in a very abrupt and remarkable manner. 
The more this folded structure of the earth’s crust is 
studied the more evident it becomes that it has not been 
brought about by any subterranean forces acting vertically 
upwards. We can only find a reasonable explanation of the 
complicated, and often inverted foldings of mountainous 
districts, by assuming that the force was a lateral one, and 
that it has ridged up the rocks, just as a piece of paper or 
a cloth is puckered when it is laid flat upon the table and the 
fingers pressed upon it with a slight sliding movement. 
That nearly all the elevations of old sea bottoms into 
hills and mountains have been produced by lateral thrust all 
