54 Notes on the Geology of South Ferriby. 
South Ferriby is situated on the northern escarpment of the 
Lincolnshire Chalk Wolds—on a slope which in pre-glacial 
times rose direct from the waters of the Humber, then a much 
more formidable river than itis to-day. Since that time however 
various glacial and post-glacial deposits have been formed on and 
around the chalk hills. These have occupied part of the bed of 
the older river, the present estuary being confined within much 
narrower limits. The later deposits have also added to the 
beauty of the scenery, contributed much towards the fertility of 
the district, and perhaps of more import at the present time, they 
have added many interesting chapters to the early history of the 
area. 
The principal geological deposit around Ferriby is un- 
doubtedly the Chalk. The Kimeridge clay occurs in places at the 
foot of the wolds, and in the village itself can be identified by 
the marshy nature of the ground, and from the Belemnites 
and Grypheea dilatata (a large oyster-like shell)—characteristic 
Kimeridge species, which can be secured with a little digging. 
This dark soft clay can also be traced at the foot of the chalk 
towards Horkstow, Saxby, etc., though it is generally covered up 
by later beds. 
The chalk wolds are roughly six miles in width, and reach a 
height of from 300 to 500 feet. At the Ferriby end they are about 
100 feet in height. On the west the valley of the Ancholme forms 
a boundary, from which the chalk gently rises, and on the 
east the same rock terminates in a fairly steep slope, which 
the Geological Surveyors recognise as a buried sea cliff of pre- 
glacial age—a continuation of that which is known to be buried 
under the drifts of Holderness. 
Of the Lower Cretaceous beds, though well developed in this 
county not far away, there is little or nothing at Ferriby. The 
first division of the Upper Cretaceous series however occurs, viz., 
the Red Chalk, and its position can be traced by a well defined 
line of springs which supply the village with excellent drinking 
water, notwithstanding that some are immediately below the 
church-yard ! 
The Red Chalk makes its first appearance on the foreshore 
towards the Ferriby Chalk pit, nearlya mile east of the Hall. At 
