Part of Gloucestershire and Somersetshire. 363 



the ridge of the old red sandstone, is thence spread through the parishes of 

 Roborough and Shipham, extending into the valley on the west. The cal- 

 careous conglomerate, thus overlying the old red sandstone, slate-clay, and 

 carboniferous limestone, dips in the lower strata 33° toward the west, but 

 the higher strata soon acquire an horizontal arrangement. I have represented 

 this position of the conglomerate in the vicinity of Shipham, in the small Sec- 

 tion, Plate XXXIX., placed below that part of Section No. 5 with which its 

 structure corresponds. 



The flanks of Mendip also testify the same destructive agency. On the 

 southern side, the calcareous conglomerate forms an exterior border of low 

 hills, ranging along its foot, the extended strata of which gently inclining 

 toward the south, descend low into the plain. This structure may be distinctly 

 observed in proceeding from Wells to Easton, Westbury, and Rodney Stoke ; 

 but before we reach Cheddar and Axbridge, the high conglomerate border 

 has merged into the vale. To the southward the conglomerate is succeeded 

 by new red clay marl, which supports lias in the form of truncated cones, — as 

 in the knolls of Cheddar and Brent, — the latter surmounted by a cap of 

 oolite ; or in narrow extended ridges, as in those of Weare and Badgworth ; 

 while still more south, in the Polden hills, the lias ridges acquire greater 

 importance. The prevailing sub-soil of the rich vales of the Axe, the Brue, 

 and the Parret, is probably throughout, like that of the vales of Gloucester 

 and Evesham, either new red clay-marl, or lias. 



On the northern side of Mendip, the declivity is faced high up by a great 

 deposition of the calcareous conglomerate ; which forms the immediate brow 

 of the range, and attains to a considerable elevation between East Harptree 

 and Burrington : but further west it gradually declines, skirting the foot of the 

 hills, and sinking into the vale. I may here observe, that the calcareous con- 

 glomerate itself bears the marks of the same destructive action, as the older 

 rocks from whose materials it was derived*. Of this the beautiful defile 

 of Rickford, through which the public road passes from Blagdon to Langford, 

 is an example ; being scooped out of this formation, the opposite sides cor- 

 responding in salient and re-entering angles. The calcareous conglomerate 

 is here, as in many other quarters, disposed in firmly consolidated horizontal 

 strata, each about four feet in thickness. 



§ 44. Before I leave Mendip, I must notice the high eminence of sandstone, 

 which rises in the range above East Harptree, and to which I have already 

 adverted (§40.). The strata of this rock are horizontally disposed, and in 



* The origin, however, of these appearances may be referred to different periods. 



