■WOOD AND ROME LINCOLNSHIRE AND S.E. YORKSHIRE. 177 



Fig. 12. — Section of the " CUff'' at lledding's Wood, two miles east 



of Applehy. 



Froddingham. Cliff. 



1. The Lias. 2. The Lower Oolite, x. Denudation-beds, consisting of 10 feet 

 of red sand overlain by 30 feet of rounded Oolitic gravel. Height of the 

 *' cliff" (as ascertained by a bore carried down from the gravel half a mile 

 east of the "cliff") about 250 feet. The steepness of the scarp is much 

 exaggerated. 



Notwithstanding that the position of the Glacial clay near Ely ton, 

 in fig. 5, seems to involve the assumption that the '• cliff" existed 

 as a ridge in the Glacial sea, yet the foregoing section shows that the 

 present state of the scarp of that ridge has been produced by the Post- 

 glacial denudation. If the position of the gravel thus capping the 

 "cliff" in fig. 12 be compared with that occupied by the Upper 

 Glacial clay both east and west of the " cliff" in fig. 5, and east of 

 it in fig. 6, and if it be remembered that this clay to the southward, 

 at Ponton (in fig. 4), and to the northward, at Speeton (in fig. 1), 

 occurs at elevations twice as great as that of the cliff" itself (not to 

 mention the obstacle presented by the chff-ridge to the transmission 

 of the chalk debris, were it out of the water), the inference that this 

 ridge was enveloped by that clay appears to us unavoidable. Its 

 subsequent denudation, and the Postglacial age of the sands and 

 gravels which occupy it, necessarily follow, as the whole structure of 

 the region under consideration negatives the probability of any of 

 these deposits belonging to the Middle Glacial series, left bare by the 

 denudation of the Upper Glacial clay. The latter part of this infer- 

 ence, however, is rendered unnecessary where these sands and gravels, 

 leaving the summit of the ridge, touch and rest on the edge of 

 patches of the Glacial clay, as they do more to the southward by 

 Glentham and Spridlington. The southern edge of the mid-Lin- 

 colnshire Glacial-clay tract is also occupied by a considerable sheet 

 of gravelly sand, which covers the country between TattershaU and 

 Horncastle for a considerable breadth, and has its northern boun- 

 dary by Edlington Moor, Eoughton, and Wood Enderby, mostly 

 resting on the Oolitic clay, but at Houghton passing a little over the 

 Glacial clay. It enters and occupies the bottom of the Bain vaUey 

 as far up as Horncastle, but in so small a degree that, in the ab- 

 sence of any evidence pointing to its being a river-valley gravel, we 

 may regard it as belonging to the marine denudation-beds of the early 

 Postglacial period. A gravel of similar age occurs on the opposite side 

 of the narrow arm of the fen that runs up to Lincoln, namely, near 

 Metheringham. This touches, and appears to rest slightly on, the 

 Glacial-clay outlier of Timberland. There is another deposit which 

 skirts this fen-arm, consisting of a sandy warp-clay, and found by 

 us to be about 9 feet thick, near Langworth village, and at Nocton 



