214 STATHER : NOTES ON THE DRIFTS OF THE HUMBER GAP. 
2. Chalk Valley Gravel. — At South Ferriby, west of the 
house, at the point where the Upper Chiy dips below beach-level 
(fig. 10), the continuation of the clitf shows a chalky, gravelly clay, 
which gradually passes into pure gravel, consisting of angular and 
sub-angular bits of chalk and flint, containing at first, a few foreign 
pebbles, but further west the foreign element dies out entirely 
(fig. 11). From the Wold overlooking the section from the south, 
the gravel can be seen to occupy a delta at the mouth of a shallow 
('halk valley, which the Humber intersects. 
(Although discussion of the forest-beds of the Humber district 
is not within the scope of the present paper, it may be well to note 
that on the foreshore on both sides of the river, immediately to the 
west of the sections above described, patches of peat occur, contain- 
ing trunks of trees, bones, etc.) 
The Boulders. — The Red Cliff clays are rich in erratics, and 
the shore below the section is strewn with boulders varying from the 
size of a pebble to two or three feet in diameter, derived from 
the rapidly wasting cliff. The following list of boulders, derived 
chiefly, I believe, from the Lower Clay, is compiled from my notes : — 
Granites, many distinct types, chiefly pink. 
*Shap granite (S. Ferriby). 
Augite syenite (laurvikite of Brogger). 
Rhomb porphyry, several varieties. 
Porpliyrites. 
Basalts. 
Amygdaloidal-basalt. 
Dolerite. 
Mica Schist. 
Gtirnetiferous schist. 
Gneiss of various kinds. 
Quartzite. 
Vein quartz. 
Sedimentary Rocks. 
Grits \ 
Conglomerates [ Probably Pre-Carboniferous. 
Greywacke J 
*Notes on the occurrence of Shap Granite in Lincolnshire by Thos. Sheppard, 
Naturalist, November, 1896. 
