Notes on the Geology of South Ferriby. 67 
found in slabs strewn about on the beach. It is very firm, being a 
natural concrete, made from the particles of lime and grains of 
sand forming the bed. Underneath it are embedded pebbles of 
chalk, etc., some of which protrude through the upper surface. 
Owing to the slipping of the clay it was for a long time 
difficult to define the precise relation of this bed with the others in 
the series. That the boulder clay rested immediately upon it 
seemed hardly probable, though once it was difficult to find that it 
was otherwise. A recent heavy tide however cleared the foot of the 
cliffs fairly well and shewed the true position of the sandstone. 
It rests directly upon the chalk rubble, is immediately covered 
by the stoneless laminated clay, which in turn is covered by 
the purple clay. The age of the sandstone appears to be 
just prior to the formation of the purple clay.* 
(6.) Here the solid chalk is represented occupying the 
_ bottom 12 to 18 inches of the cliffs. The upper part is dislocated 
in places, and in other parts is curiously weathered. It contains 
deep ‘ pipes,’ evidently of great antiquity (similar to those on the 
Yorkshire wolds), as the material they contain does not appear to 
have been derived from the over-lying clays. These pipes 
_ average 6 to 8 inches in diameter, and penetrate to a depth of two 
q or three feet or more. On the beach they can be seen in section 
as circular clay patches in the chalk. It was at the south-west 
_ end of this outcrop in the cliffs that the glacially-striated slab of 
chalk already described in these notes was found. 
(7). This bed consists of fine sandy silt, evidently an old 
deposit of the Humber. It forms the flat land in front of Ferriby 
Hall and towards Ferriby Sluice. At its north east end, where it 
is intermixed with coarse sand and gravel, it contains a large 
quantity of Helix aspersa, Helix nemovalis, and other land shells, 
, 
; *Prof. John Phillips recorded a similar sandstone directly on the 
‘chalk at Hessle. I recently found it, ona level with the railway metals, 
just west of the bridge carrying Wold Field Lane over the railway. 
{In the Geological Survey Memoir, 1890, p. 150, Mr. Jukes-Browne 
describes the section in the cliffs at this point as under :— 
‘Soil and weathered clay (3 or 4 feet) passing down into reddish- 
7 brown sandy boulder clay 10 feet. 
_ Red-brown clay and light coloured sand, interlaminated and 
. resting on a layer of hard ripple marked sandstone 1 foot. 
_ Coarse gravel of large rolled stones, grey chalk and red chalk 
among them, seen for 1 foot. 
__Hard grey chalk on the beach below 1 foot, 
