WILMORE : THORNTON, MARTON AND BROUGHTON-IN-CRAVEN. 349 
or more of the small longitudinal streams, the low hills are 
thus separated into roughly Unear sets. There are also numerous 
" dry valleys," both of a longitudinal and transverse nature. 
There are numerous quarries, many of them now largely 
grown over, though a few give occasional employment to two 
or three men, and one at Thornton-in-Craven is worked on a 
large scale. There is no Hme-burning carried on nowadays, 
the stone being quarried for road metal and for " asphalt chip- 
pings." Of course the fences, except those in the drift-covered 
areas, usually consist of limestone walls. In the eight or ten 
square miles with which this paper deals, there are over 30 
quarry cuttings known to the writer, and a few small road-side 
sections. The rivers seldom furnish sections. 
The limestone is almost exclusively dark in colour, almost 
black in many cases, but weathering grey or brownish-grey on 
exposure. More rarely it weathers somewhat yellow. It is 
always quite well-bedded, usually thinly bedded, and in almost 
every quarry there are partings of shale. Veins of calcite are 
common almost everywhere, and occasionally veins of barytes 
are seen. Fluor occurs, but it is quite rare, and hydrated iron 
oxide is present in small quantity in irregular patches. There 
appears to be very little trace of galena. 
Some remarks on the lithology of the district wiU be found, 
with the descriptions of the various quarries, in the following 
pages, and photographs of thin sections of some of the rocks 
are given on Plates XLI. to XLV. 
Almost every exposure, and certainly every one of con- 
siderable size, shows signs of the disturbance to which the rocks 
of the district have been subjected. I do not know a large 
cutting which does not show abundant shckensiding or faulting 
or bending of the beds, and occasionally — as at Gill Rock for 
instance — all three evidences of disturbance are seen in one 
quarry. 
There is no continuous section in the district, and as the dips 
change very rapidly, often in the same cutting, it is not easy 
to correlate the various beds or to estimate the thickness of 
strata exposed. The occurrence of so much drift adds to the 
difficulties of study. 
G 
