File:The Quarterly journal of the Geological Society of London (13960026463).jpg

36 ME. H. T. BEOWN ON THE PEEMIA.N
effects of the great Post-Carboniferous, Pre-Permian movements
were at a maximum.
Our Leicestershire rocks, on the other hand, are so entirely dis-
similar, both in lithological characters and succession, to the deposits
which occur on the eastern side of the Pennine chain from Notting-
hamshire to Durham, and which doubtless underlie a large portion
of the north-east of England, that on this account alone we should
suspect that the two series were laid down in different basins. We
have seen that the Leicestershire rocks thin out rapidly to the north-
east and east against an old land-barrier

and Mr. E. Wilson, F.G.S.
('Midland Naturalist,' vol. iv. p. 97 et seq.\ has clearly shown that,
whilst the Permians of the north-east of England thicken out towards
the north and east, and acquire in these directions the characters of
deeper-water deposits, the same beds when traced to the southward
become more arenaceous, thin out, and ultimately die away alto-
gether in the neighbourhood of Nottingham, owing to the Coal-
measures rising up beneath them and forming what, in Permian
times, was a land-barrier.
The most northerly exposure of the Leicestershire Permian is at
Ingleby, 13 miles south-west of the nearest outcrop of the Notting-
hamshire Permian. North and east of Ingleby the Permian is
absent

• ,

and we know, from the results of trials for coal at Wilford,
Clifton, Highfield, Chitwell, and Owthorpe, that the same is the case
to the south and south-west of Nottingham. These facts prove the
existence of a land-barrier between the two Permian lakes at this
point

and there can be but little doubt that this had its origin in
the southerly extension of the Pennine disturbance, which we have
seen produced well-marked effects even much further to the south.
It is possible, after making due allowance for a certain amount
of denudation in Bunter and Lower Keuper times, to trace, with a
fair approximation to accuracy, a small portion of the old coast-line
of the western Permian lake. Its probable course, commencing on
the north, was through Stanton-Bridge, Ticknall, Hartshorn, Black-
fordby, Ashby, a little west of Heather, Market Bnsworth, then on
towards the northern part of the Warwickshire Coal-field, whence it
must have taken a southerly course for some distance, thus forming
a somewhat deeply indented bay facing north-west. The rocks
forming the land on the south of this bay had already been folded in
a north-north-westerly and south-south-easterly direction

and since
this folding of the Carboniferous and older Palaeozoics brought to
the surface beds of varying hardness, there must have resulted a
series of ridges and valleys to some extent coincident with the
strike of the beds, and resembling very much the contour of the
ground at the present time in the Nuneaton-Hartshill district.
Down these strike- valleys flowed the streams, bringing detritus into
the Permian lake from the high ground on the south. We have

The so-called Permian between Derby and Ilkeston has been shown by
Mr. Wilson to be brecciated Bunter sandstone, and that of Dale Mill to be
Lower Coal-measure