“ea ree 
VOL. XIV. (1) MENDIP ARCHIPELAGO 67 
district mark the proximity of the shore. Such was the 
geography at the close of the Liassic epoch. 
Local elevations of the sea-floor, together with pene- 
contemporaneous erosion occurred early in the Inferior 
Oolite epoch,’ and again, about the middle. Further, 
these conditions prevailed still later, before the deposition 
of the Upper 77zgonza-grit of the Cotteswolds: then the 
Mendips were elevated, and the Mesozoic strata were 
thrown into a series of small flexures,” and were denuded. 
The rocks that were laid bare during this erosion—the 
Bajocian denudation it has been termed—were much 
pierced by boring animals, irrespective of their date. 
In places the Mendip marginal deposits were raised 
above sea level. Sub-aérial and marine denudation 
played their respective parts on these recently-elevated 
Mesozoic strata, fissures in the Carboniferous Lime- 
stone received the products of the denudation, and 
thus, as Mr. H. B. Woodward observes,3 ‘it must 
be remembered that the remains of Mvzcrolestes found 
in a fissure near Frome, occurred in association with 
infillings of Oolite, as well as of Carboniferous age.” 
This denudation may have been the cause of many of the 
remarkable dykes of this district. 
The borings were long ago noted by De la Beche,* and 
his observations tend to support this Bajocian denudation. 
He observed, “To mark the date of these borings still 
more perfectly the same vicinity [near Frome] fortunately 
presents us with evidence of a shingle, accumulated at 
the time of the Lias (organic remains characteristic of 
that deposit as it occurs in the neighbourhood, having 
been found in it), having been consolidated and planed 
1 S. S. Buckman, Bajocian of North Cotteswolds ; Quart. Journ. Geol. Soc., vol. lvii, 
p- 153- 2 Ibid., p. 149. 
3 Mem. Geol. Surv., “ Jurassic Rocks, etc.,’ 
4 “Geological Observer,” (1853), pp. 486, 487, figs. 176, 177. 
? 
vol. iii., p. 98. 
