TIDDEMAN : LIMESTONE CONGLOMERATES. 
439 
hills between Appletreewick and Greenhow Hill last Summer to come 
upon some evidence which, to some extent, supports the conviction 
at which I had arrived from a priori grounds. 
Dibbles Gill, a pleasant little upland stream runs down from the 
Millstone Grit Fells above, and about Grimwith Reservoir it passes 
over the Yoredale beds, here somewhat degenerate in their type, and 
goes under the road from Grassington to Greenhow hill at Dibbles 
Bridge. Lower down it crosses the main Craven Fault, that branch 
which brings down the picturesque grit escarpment of Fancarl Crag 
against the Mountain Limestone. In its further course it runs in a 
rather deep ravine between Limestone hills, formerly much mined 
for lead, and enters the Wharfe between Burnsall and Appletreewick. 
' It is with the upper part above the Craven Fault that w r e are now 
concerned. A good sized quarry below Dibbles Bridge shows a 
black limestone, containing beds of chert and abundant remains of 
Producta gigantea ; corals also occur in it. These beds have much 
the look of the Hardraw Scar Limestone. They extend beneath the 
bridge with a northerly dip. 
Nothing more is seen up-stream for about 300 yards. We then 
meet with a sandy-looking limestone forming the bed of the stream, 
and here and there are exposures which show pebbles of limestone in 
the matrix. Above this again is a black limestone with few fossils 
but containing corals. The beds are not well seen in the stream, 
but if we leave the stream and go up through the fields along the 
strike, between this point and the road across the moor to Grimswith 
Reservoir, we shall find old quarries in them, and the dry walls 
around bear ample evidence of the rock quarried in them, though 
the quarries themselves are now unfortunately grassed over. These 
walls are full of excellent specimens ot limestone conglomerates. 
The pebbles range in size generally from a mustard seed to a broad 
bean, but bigger fragments are occasionally seen. The whole material 
looks very much like a concrete. The pebbles are light-blue grey 
and the material is of a yellowish colour and feels gritty. 
Some other evidences of land or shallow water conditions were 
found in the tip from the mining level, which comes out at Kell Well, 
east of Grimwith Reservoir, and cuts through the same set of beds. 
