C.—GEOLOGY 79 
have for core in Shropshire the worn plexus of Lower Palzozoic rocks 
which had been foothills to the Devonian Caledonian Alps. The Charn- 
wood core of the eastern limb in Leicestershire is compressed Pre-Cam- 
brian and igneous material. Several, probably all, synclines within the 
Carboniferous synclinoria are disposed between ribs of reinforcement in 
the pre-Carboniferous foundations, which are aligned with the anticlinals 
of their cores. The synclinals deepened intermittently but progressively 
as the geosynclinal filled ; and though as a whole the Province may occupy 
an early downfold in the foreland of the Hercynian alpine chain, its 
leading fold-lines are re-emphasised and rejuvenated structures which 
in origin are older. 
In the beginnings of my study of fold and fault distribution in the 
Pennines, I was content to follow custom, and use established regional 
names for trend. The East Pennine Coalfield has obvious north-west- 
south-east elongation and is continuous to Charnwood. Its longitudinal 
folds and faults, though they bend in flowing curves, do not stray far 
from the Charnian direction. The north-east-south-west oval of the 
Cheshire Basin may be Caledonian, and though it lies athwart the com- 
pressed folds of Wales, it is flanked by folds and faults which are 
rejuvenated Caledonian structures. The Pennines as a hill range trend 
north and south, but north-south folds are only dominant in them for 
some twenty miles along the borders of Derbyshire and Cheshire, where 
they are bunched between the Caledonian trough of Cheshire and the 
Peakland extension of the Charnwood ridge. Continuing with slight 
divergence through North Staffordshire, they point southward as a hand 
with outstretched fingers, the thumb along the Caledonian folds of 
Shropshire, the long fingers following the coalfields of the Black Country 
and Warwickshire, and the little finger the Charnian of Leicestershire— 
a Midland fan of congruent folds and faults, Caledonian and Charnian, 
but on the average ‘ Pennine’ in direction. Northwards also, but in 
curves which are asymmetric, trend-lines from the central Pennines open 
out, in Lancashire bending westwards but in Yorkshire eastwards, to 
return southwards and unite with Charnian structures in Derbyshire and 
Nottinghamshire. 
Surely in this continuous variation of fold and fault direction within 
the type area from which the Pennine trend was named, we see the appli- 
cation of regional trend nomenclature reduced to an absurdity. The 
Pennine uplift is not a simple group of parallel pressure ridges ; and, 
having traced the loosening of its sheaf of structures through the Midlands, 
and seen them almost box the compass in the coalfields on either side, 
I have concluded that as a synonym for north-south trend of structure 
the name of ‘ Pennine’ must disappear. Forced correlation in use of 
nomenclature cannot express tectonic virgation, and for precision in 
indicating fold direction in the course of this address, I have gone 
back to compass-bearing, and for specifying fault-lines I am content to 
mention their alignment and locality. 
Charnian, Caledonian, Hercynian, are well-established names for 
ancient mountain ranges. With reason they are used to designate 
structure impressed when those mountain folds were being compressed. 
