347 
NOTES ON THE GEOLOGY OF THORNTON, MARTON, AND 
BROUGHTON-IN-CRAVEN, YORKSHIRE. 
BY A. WILMORE, B.SC, F.G.S. 
{Read 20th February, 1908. Manuscrij)t received 
Uth November, 1908.) 
The district with which this paper deals forms part of 
the celebrated " Craven pasture ground." It lies at the western 
end of the Craven or Aire Gap, and the Leeds and Liverpool 
Canal traverses it on its way through the Pennines. It is low, 
undulating country, varying in height from 300 to 700 feet, 
most of it lying between 400 and 600 feet O.D. It is drained 
by a number of small winding streams, probably the outcome 
of an inherited drainage. These streams wind in and out among 
the low rounded hills with which the district is studded, meander- 
ing through the " mosses " or alluvial flats, the drained " meres " 
which form the low fertile grass lands for which this part of 
Craven is so famous. Marton is said to be the tun or town 
by the mere. 
Much of the district is covered with glacial deposits of 
very variable nature and thickness, and in the opening up of 
the numerous quarries it has usually been necessary to remove 
a considerable quantity of drift. The quarries are consequently 
found on the slopes or near the summits of the low hills. I do 
not know, in the low flat lands, a single cutting which has reached 
the solid rock below. There is a good typical section of Boulder 
Clay, containing striated boulders of limestone and green grit 
(probably Silurian), lying on the upturned edge of the lime- 
stone, in a quarry at Punch Bowl Hill, half a mile south-west 
of Thornton-in-Craven. It is close to the west side of the road 
from Skipton to Colne. Exposure (4) on the sketch map, p. 348. 
The roimded hills which form such a characteristic feature 
of the district have a tendency towards a linear arrangement, 
the general direction being the same as the strike of the 
folds. Where a transverse stream collects the waters of two 
