Yol. 68.] GLA.CTAL SECTIONS KOIJND SUBBUEX. 27 



and several yards long, of Boulder Clay. It is banded for a foot 

 or two at its base, but above is normal tough clay. This sheet 

 terminates at its south-western end in a contorted mass of yellow 

 and white sand, which is rolled up into the clay. Gravels lie round 

 the whole. 



These pits are situated on the south side of a lateral valley. At 

 about the same level, on the north side, is Green's Pit (1) with the 

 contorted mass of sand described and figured by Dr. Marr. Across 

 the Stour, the Ballingdon-Grove Pits (12) are at their western end 

 now chiefly sand, though, at one time, masses of clay and masses of 

 sand were here intermingled confusedly. The clay has been 

 mostly removed; but early in 1911 I found that a block of clay 

 was being dug, some 20 feet broad and 10 or 12 deep, with sand 

 on each side. A few weeks later all the clay had been removed, 

 and the block was seen to have been embedded in fine sands, 

 which dipped, not riverwards, but away from the valley. 



At the eastern end of these same Grove Pits, in the digging of 

 coarse gravel, two sheets of Boulder Clay have been cut through. 

 One was 40 feet long, 4 to 8 feet thick, abruptly cut off at one 

 end ; the shape of the other end was hidden by a little talus. 



In the outer Alexandra Pit (5) there is a sheet of the clay 

 resting upon gravels. At first, appearances were not inconsistent 

 with deposition in situ ; but, as excavation progressed, the clay was 

 seen to lie on a ridge of the gravels, and to bend down over this on 

 each side. Further cutting has revealed it to be a sheet, 40 or 50 

 yards long by about 4 feet in thickness, ending abruptly against the 

 gravels, which lie around it, above as well as below. 



These isolated sheets and masses cannot have been formed 

 in situ ; they are as much boulders as any mass in the gravel ; 

 plainly they have been transported. All of them lie at levels below 

 the base of the Boulder Clay, as seen in the Gallows-Hill (3) and 

 inner Alexandra (6) Pits, and far below the higher parts of the 

 plateau : their transport would be down hill. All of them lie on 

 slopes of the present river-valley ; and it will be remembered that 

 clay can slip down very moderate slopes. At the brickyard near 

 Ballycastle Railway-Station (Antrim), for instance, I saw Boulder 

 Clay slipping down the hillside, though the slope was only 1 in 8. 

 The excavation was shallow, but the turf for many yards above it 

 was rent and fissured. The contorted sand and clay in the Victoria 

 Pits (2) bend as they would be bent by a slip down a hillside. The 

 jumble at the western end of the Ballingdon-Grove Pit (12) may 

 be fallen masses, on a steeper slope, or down a cliff where the river 

 had been undermining. Ice may have assisted in transporting the 

 sheets. The coarse and strongly current-bedded gravels which lie 

 around or adjacent indicate violent and varying water-action. 



In the Eailway-Station Chalk-pit (8) and Whorlow's Chalk-pit 

 (11), which are about 300 yards apart, and each at about 150 feet 

 above Ordnance-datum, clay is seen to rest upon irregular gravels. 

 This, however, does not seem to be normal Chalky Boulder Clay ; 

 I think that it may be remanie. Such would naturally often be 

 formed during the re-excavation of the vallev. 



