VACGHAX : THE KNOLL REGION OF CLITHEROE, ETC. 49 
Millstone Grit. 
Yoredales, -lOO'-GOO'. 
Bowland Shales. 
Carboniferous Liinestone (up to | 
top of Great Scar), 400'-800'. | 
bnaies-intli- LDnestone 950Q/ 
(including Pendleside r " 
1 5000 
Limestone at top). J 
Clitheroe lAmestone \ 
. , , I Clitheroe Knollsl 
mclud- 1 , ^. , 32o0 
\ Black Chatourn 1 
ing ^ . 
\ V Limestone ) 
Base of Carboniferous Limestone. 
He points to the enormous difference : — some 800 feet in the 
North deposited at the same time as 6000 feet to the South (taking 
only the Carb. Limestone). Certain modifications are, however, 
necessary in order to obtain a correct comparison, and it will be more 
convincing if we take maxima North of the Faults and minima on 
the South. 
(a) It is not at all probable that the Yoredales are entirely above 
the Pendleside Limestone ; hence, to obtain a maximum, we assume 
that the top of the Yoredales corresponds to the top of the Pendleside 
Limestone. 
(b) The base of the Carboniferous Limestone of Ligleborough is 
of C-S age and therefore above not only the Black Limestone, but also 
above the lower line of Clitheroe knolls (Pimlico-Downham) ; hence, 
the only part of the Clitheroe Limestone we can take account of in 
this comparison is the upper line of knolls (Salt-Hill, Warsaw, etc.) — say 
1500 feet. 
(c) The estimated thickness of the Shales-with-Limestone may 
be reduced to 2000 feet as a minimum. 
On the other hand, there is undoubtedly an unconformity between 
the Knolls and the Shales-with-Limestone which would considerably 
increase the estimate — this we entirely omit. 
Hence : — Minimum thickness S. of Faults 3500 feet. 
Maximum thickness N. of Faults 1700 foet. 
