BOULDEE- CLAYS OF LINCOLNSHIRE. 



119 



(if not a cliff) of chalk at this place, and probably all along the line 

 of rise from the lower plain to the Wold hills. 



At the same time it is clear that the Boulder-clay overrode 

 this cliff-line, and buried a considerable portion of the Wold land 

 to the westward. A thin outlier caps the high ridge between 

 Hawerby and Wold Newton, the summit of which is 382 feet above 

 datum-level ; and the same Boulder-clay occupies the valley-bottom 

 which runs northward from Wold Newton to E-avendale. 



Fig. 2. — Plan of the country near Hatcliffe. (Scale 1 inch to a mile. 

 The ground occupied by Drift is indicated by diagonal shading.) 



Kear East Eavendale there is direct continuity between the clay 

 in this valley and that outside the chalk ridge ; and the mapping 

 east of Hatcliffe (fig. 2) suggests the existence of a cliff-line breached 

 by the battering of ice before or during the deposition of the Boulder- 

 clay. From this locality the brown clays are traceable northward 

 by Laceby and Brocklesby to Barrow and Barton-on-Humber. 



Westerly Extension. — From Hessle, on the north side of the 

 Humber, the so-called Hessle Clay sweeps westwards to North 

 Ferriby, and as it is also found on the south side of the river at 

 Barton and near South Ferriby, Mr. Searles Wood justly concluded 

 that it had once filled the great gap in the Wolds through which 

 the Humber flows. But if the Boulder-clay extended through this 

 gap, we should certainly expect to find it on the western side of the 

 Wolds, both north and south of the Humber, at similar low levels. 

 Mr. Searles Wood could not find it, and he suggests some elaborate 

 hypotheses to account for its supposed absence. These, however, 

 are fortunately rendered unnecessary by the simple fact that it is 

 not absent, but present in some force, both to the southward and 

 "westward of South Ferriby. It may be seen near Horkstow Bridge, 

 1| mile S.W. of Ferriby, and again in the dyke at the east end of 

 Winterton Holme, whence it extends westward to Winterton, and 

 thence northward to Winteringham, and it probably underlies parts 

 of the alluvium of the Ancholme. Along the eastern border of this 



