70 SECTIONAL ADDRESSES 
each major fold axis in the Midlands, if extended northwards, would come 
to Manchester. Within the convergence the pitch of folds is somewhat 
variable, but there is no evidence of interweaving, or rise and fall by cross- 
folding, which can be interpreted as compounding with broad east-west 
Hercynian folds. North and west of Buxton folds in the Millstone 
Grit country swing southwards round the High Peak ridge, and there 
is rude symmetry of fold distribution in Staffordshire and Derbyshire 
about the north-west line of the extended Charnian axis. 
Across the Manchester Coalfield the broad trough is cut to ribbons by 
north-west faults, which break the measures, as, bending, they dive 
towards the Cheshire Plain. Minor folds alongside major faults have 
axes which diverge westwards from the Pennine fold. The east-west 
Rossendale anticline of mid-Lancashire is so broad a swell that, as with 
its neighbour the even broader Cheshire basin, the location of its merging 
in the Pennine fold is ill-defined. ‘The sharp monocline which makes the 
Pennine crest near Todmorden bends round to the east towards Keighley, 
and the triangular trough of the Burnley Coalfield is evidence that the 
Charnian midrib of the South Pennine structure, which is more or less 
continuous from Leicestershire, has here ended. 
Beyond the North Lancashire Coalfield the trend of sharp folds in the 
Craven lowlands is north-easterly. They swing to the eastwards through 
Skipton as far as Leeds, to follow and define the northern edge of the 
Yorkshire Coalfield. From their divergence to the westwards it is evident 
that the Craven lowlands and North-west Lancashire is a structural unit 
quite distinct from the North Lancashire Coalfield, and there is similarity 
of structure between this Pendle-Bowland area adjacent to the Craven 
Faults and the fold virgation in North Staffordshire. 
The structure of the North Wales coalfield country north-west from 
Shropshire has lately been discussed by officers of the Geological Survey, 
and folds affecting Carboniferous rocks are interpreted as due to tightening 
and adjustment of structures already developed in the Lower Palzozoic 
rocks.13 Whether or not the upstanding mass of the Longmynd has 
protected from Hercynian fold invasion the plains of Southern Cheshire, 
resultant movement in Flint and Denbighshire has produced the horse- 
shoe anticlines whose range is more or less parallel to the Lower Palzozoic 
outcrop, and in groups separated by great tear faults they bulge eastwards 
upon the Cheshire Plain. 
FAULT-PATTERN. 
Following the consideration of fold axes, a similar plotting and reduction 
has been made " of the distribution and alignment of recorded faults, and 
the intricate patterning of Fig. 2 results. From comparisons of super- 
posed diagrams, as first reduced to the }-in. scale, it is clear that the 
dominant families of faults follow the limbs of folds, but that they sweep 
in curves of radius larger than the axial curvature of folds. No fault 
13 C, B. Wedd, ‘ The Principles of Paleozoic and later Tectonic Structure 
between the Longmynd and the Berwyns,’ H.M.G.S. Summary of Progress for 
$93T,/ Pt. TE pt i(r932): 
14 Also by Dr. Pulfrey. 
