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cl i a 
PP ee ere ere sar & 
ly OW Ghee ae Se 
A CHAPTER IN THE PHYSICAL GEOGRAPHY OF THE PAST. 47 
not visible, and can only be inferred from the want of correspon- 
dence in the beds on either side of the anticlinal. 
On the West of the Charnwood area the actual super-position 
of the Carboniferous strata upon their old sea bottom, consisting 
-of Charnwood rocks, is not visible, owing to the existence of 
another large fault running parallel with the anticlinal fault, letting 
down the Coal Measures against the former. It is only on the 
North and North-West that the Mountain Limestone, the lowest 
member of the Carboniferous system, is found resting upon the 
Forest rocks ; and here we find unmistakable evidence that the 
latter must have been immensely disturbed and denuded before 
the limestone was laid down upon them. Such a super-position is 
known as an wzconformity, in contradistinction to the term con- 
JSormity, which is used to express an unbroken sequence of 
sedimentation, like, for instance, that of the various members 
of the Carboniferous System from the Mountain Limestone right 
up to the Coal Measures. 
From the fault last referred to the Coal Measures occur at the 
surface to a little east of Burton, where they are lost sight of 
under the mantle of New Red Rocks which surround the 
Leicestershire Coalfield. These Coal Measures, as far west as we 
can trace them, have also been affected by the great earth move- 
ments which brought about the Charnwood axis of elevation, and 
show a system of faults and folds approximately parallel with this. 
They have also been subjected to plications and faulting at right 
angles to this axis, with the result that the strata of the western 
or more productive parts of the Coalfield have been thrown into 
a basin-like form, which has much conduced to their preservation. 
And here, perhaps, in dwelling upon this, it will be well to correct 
a misapprehension which has probably arisen in the minds of 
some of you, that elevated tracts of land are generally coincident 
with upward folds or ridges in the underlying rocks, whilst the 
valleys run in the troughs. This is undoubtedly sometimes the 
case, and we have seen two good instances of it in the structure 
of the Pennine and the Charnwood Ranges ; but more frequently 
the very reverse holds good. When a mass of strata which has 
