TIDDEMAN : CARBONIFEROUS ROCKS IN UPPER AIRE- DALE. 483 
TABLE OF THE CARBONIFEROUS ROCKS IN CRAVEN. 
Southern or Bowland 
Type. 
Feet. 
Feet. 
Northern or Yoredale 
T3pe. 
Coal Measures 
1,500 
4- 
Coal Mea- 
sures 
e laults 
J area. 
Millstone Grits 
Pendleside Grits 
(inconstant) 
8,^00 
0 - 250 
1 
J 
aven faults. — 
400—900 
Millstone ll^ 
Grits J"|- 
Yoredale Series 
Pendleside Lime- 
sto>e (with 
Knoll-Reefs) 
0-400 
O 
Shales with Lime- 
stones 
Clitheroe Lime- 
stones (with 
Knoll-Ret fs) 
2.;' 00 
X ;^,2o0 
No b:ise. 
t 
400— 8U0 
Thk Carboniferous 
Limestone (with 
couijlonierates at 
V)ase). 
The rocks on 
both sides 
of these faults 
seem to have 
been 
formed on slowly subsiding areas, but the Bowland area appears to 
have been subsiding more quickly and to a greater extent than the 
area occupied by tlie Yoredale type. It represents the downthrow 
side of the faults. The other side of the faults of course is relatively 
an upthrow. 
The question next arises : When did these earth-movements 
take place ? 
We know that some of the movements have occurred since the 
deposition of the Permian rocks, because these have in places, near 
as Ingleton, been tilted up at high angles thereby ; but we also know- 
that a far greater part of them were going on before the Permian 
rocks w^ere deposited, because these lie at different places by uncon- 
formity on all the members of the Carboniferous — a series which 
shows near Burnley a vertical thickness of three miles of rocks 
without base or completed top. The movements necessary to subject 
so gi-eat a thickness of rocks to denudation in all its members before 
the advent of the Permian epoch must have been enormous. We 
may, therefore, well believe, and indeed can hardly doubt, that the 
crust was subjected to great movements during Carboniferous times. 
