656 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 22, 
50 feet high: these, however, in the neighbourhood of Leasowe, 
were washed away by the continual encroachment of the sea many 
years ago, and their place artificially supped by an embankment, 
which has to be continually repaired, and, after heavy storms, even 
partially rebuilt, the cost of which is paid by an acreage-toll levied 
on the landowners of the district. 
The drainage of the district is naturally much obstructed. Deep 
sluices, like small canals, often from 16 to 20 feet deep, carry the 
water into the river Birket, which falls into Wallasey Pool, an arm, 
or tributary, of the Mersey. In the sections exposed in the Birket 
and sluices, beds of peat, often as much as 16 feet in thickness, 
are seen resting on grey clays; and on the northern portion of the 
tract a bed of sandy marine silt occurs on the peat, caused by recent 
inroads of the sea. The sand dunes, when their bases are seen, are 
found almost invariably to rest upon a surface of peat. At New 
Brighton, on the Mersey, there is a slight exception, the sand resting 
on the bare rock, belonging to the Bunter Pebble-beds. A little 
further west, the red beds of the Upper Mottled Sandstone occur, 
jutting out into the sea, forming the picturesque cliffs known as the 
“« Red Noses.”’ 
Walking along the sea-coast from the Red Noses towards Hoylake, 
a little before reaching Leasowe Castle, the section given in fig. 1 is 
reached. The sand-dunes (4) are about 35 feet in height, rest on a 
flat-surface peat (B) about 2 feet thick, which runs out seawards 
about five yards, forming a terrace, resting on a bed of pale, pure, 
grey-coloured clay (c), containing Cardium edule, and with a marshy 
growth at its surface. This clay rests upon a thin bed of peat (®) 
resting upon another bed of grey clay, covering still another seam 
of peat, which is believed to rest on the Boulder-clay, here covered 
up with sea-sand. 
In fig. 2 a greater thickness of peat is observed, and it is split in 
two by a bed of olive-green-coloured sand (8’), containing Tellina 
balthica and Cardium edule. A sand of probably the same age occurs 
in Lancashire, north of Southport, and I shall hereafter, for conve- 
nience, call it the “ Tellina-balthica sand.” 
The peat below the sand (8") is about 2 feet in thickness, and rests 
upon the usual grey clay (c) with a marshy growth at the top. Its 
base is concealed by sand, and it is doubtful whether it is marine or 
fluviatile at this point, as these conditions vary in a few yards. There 
can be little doubt that the whole of the silts of the Birket plain were 
deposited when this tract was an estuary of the Mersey, that river 
having, even in historical times, flowed through the gorge, at the 
bottom of which now runs Wallasey Pool into the sea, between Lea- 
sowe and New Brighton, until, through the outlet being choked by 
the deposition of alluvium, the drainage has to a certain extent been 
reversed. Whilst this deposition went on, freshwater forms might 
have lived in pools of fresh water in hollows of the Boulder-clay, 
simultaneously with marine forms in other pools filled by high tides 
a few feet distant,—fiuviatile and marine forms of life preponderating 
horizontally and vertically in the silts, according to whether freshets 
