16 
THE CHALK WOLDS. 
condition. The upper portion of the blue clay which is believed to 
underlie the whole vale of Pickering, shews itself beneath the chalk 
wolds at Speeton and Knapton, and at each place produces fossils much 
resembling those of the " gault” of Kent and Sussex. The lower blue 
clay appears along the north side of the vale of Pickering about Kirby - 
Moorside and Helmsley, as well as at Settrington and North Grimston, 
near Malton, and at Elloughton, near Cave ; and at several of these 
points it yields the ostrea deltoidea, which is one of the most charac- 
teristic shells of the Kimmeridge clay. 
THE CHALK WOLDS. 
The wolds of Yorkshire form one of the most remarkable fea- 
tures in this county. High and bare of trees, yet not dreary nor 
sterile, they are furrowed as all other chalk-hills, by smooth, winding, 
ramified vallies, without any channel for a stream. Where several 
of these vallies meet, they produce a very pleasing combination of 
salient and retiring slopes, which resemble, on a grand scale, the petty 
concavities and projections in the actual channel of a river. No doubt 
these vallies were excavated by water, but not by the water of rains, or 
springs, or rivulets. Some greater flood, in more ancient times, has 
performed the work, and left the traces of its distant origin in the 
pebbles which it has deposited along its course. 
From the Humber at Hessle, the high wolds range in a north-western 
direction to Riplingham Clump and Hunsley Beacon, five hundred and 
thirty-one feet high ; and, passing above Market-Weighton, reach their 
greatest elevation near Garraby Beacon, eight hundred and five feet 
above the sea. Hence, their edge continues by Wharram and Settring- 
ton, and, turning to the east, skirts the vale of Pickering, and fronts the 
sea in a long range of lofty cliffs from Speeton to Flamborough head. 
From this elevated line the surface slopes eastward to Cottingham, 
Beverley, and Driffield, and southward to Burton-Agnes and Bridling- 
