PROCEEDINGS OE GEOLOGICAL SOCIETIES. 



193 



stone, sometimes water-worn, together with rounded sandstone and lime- 

 stone pebbles, occur in abundance, embedded in the clay, and the whole is 

 surmounted by the remains of the denuded rocks which once occupied the 

 next position in ascending order. 



In the quarries near Sandy Gate, Habergham Eaves, 462 feet above the 

 level of the sea, the drift is from 30 to 50 feet deep. It consists of dense 

 blue clay at the bottom, and gradually passes into dark brown near the 

 top. Large boulders of sandstone, similar to that which lies beneath, oc- 

 cur in these deposits, few of which appear to have suffered from the action 

 of water. From their positions in the clay it may readily be inferred that 

 they may have fallen from the faces of the cliffs which then probably bor- 

 dered the ancient seas. Portions of encrinital limestone also occur ; and 

 there is no lack of rounded fragments of cannel, together vuth sandstone, 

 gannister, and limestone pebbles. 



In similar drift at Swindon, about two miles east of Burnley, 800 feet 

 above the level of the sea, and just under the Pennine chain, large boulders 

 of New (?) Heel Sandstone are occasionally found in connection with abun- 

 dance of rounded limestone. In former times the farmers have washed 

 the drift in Swindon valley, and have burnt the limestone thus obtained in 

 kilns, the ruins of which still remain in several places. 



During the formation of a main sewer in Trafalgar Street, Burnley (1862), 

 the workmen found a large boulder of grey granite. It was firmly em- 

 bedded in yellowish clay, at a depth of about 15 feet from the surface. En- 

 crinital limestones were also plentiful in this cutting. These deposits over- 

 lie the Thin Mine of the Burnley top beds ; the cannel bed, which is the 

 next in ascending order, having apparently been washed away. 



In various localities extensive pebble-beds occur, indicating former beds 

 of rivers, or the margins of ancient seas and lakes. Several of these bear 

 evidences of powerful currents, which, from the set or inclination of the 

 pebbles, appear to have flowed across the country in a'N.E. to S.W. di- 

 rection. This is very evident from an examination of the inclination of 

 the debris in most of the sections previously noticed, but especially in one 

 which exposes a portion of the grit scries between Ilaslingden and Helm- 

 shore. This inclination of the stones, found in pebble-beds and drift de- 

 posits generally, appears to be capable of affording more information to 

 geologists respecting currents, etc., than has yet been noted. Prior to the 

 upheaval of the Pennine chain, a broad strait must have stretched across 

 portions of Lancashire, Yorkshire, Durham, and perhaps Northumberland, 

 thus connecting the present German and Irish seas ; and the current 

 through this strait must have run from N.E. to S.W., as indicated by the 

 inclination of the pebbles and boulders in these drift deposits. Portions 

 of floating icebergs from the north of Scotland, broken off from the edges 

 of the glaciers, and charged with portions of granite and the older reeks, 

 would then find their way down this channel, and becoming stranded in 

 the shallow bays, would drop their cargoes of boulders among the silt at 

 the bottom of the turbid waters. Red Sandstone boulders might perhaps 

 be drifted in a similar manner from the neighbourhood of t he Tees, or from 

 the (dill's of what is now the Vale of York. Kncrinital limestone, not 

 water-worn, might also be transported from the north, by the same mode 

 of iceberg carriage, to the deposits in w hieh they are now found. ( >r again, 

 if we adopt the concept ions of Sir Charles Ly ell and Mr. Bull of the wasting 

 of a vast North Atlantic continent, the same results would evidently be 

 obtained. 



On the gradual upheaval of the Pennine chain, the sea would conse- 

 quently retire, both on the eastern and western sides of the country. 

 VOL. VI. 12 c 



