444 



TRANSVERSE DISLOCATIONS SOUTH OF MAY HILL. 



course for a mile or more, are snapped through by transverse faults, and often change their di- 

 rections. The high road to Ross passes through one of these breaks, on the north side of which 

 the mass of limestone called "the Rock" is thrown over with great curvatures, dipping south, 

 west and east ; whilst on the south side, the thick-bedded limestone with " ball stones/' and over- 

 lying small concretions, dips 40° west, or west -south-west. Near this disturbed spot, the few beds 

 of Ludlow Rock which are visible, are unconformable to the Old Red Sandstone 1 . 



Another transverse fault is exhibited in the sides of the road leading from Little London to 

 Mitchel Dean, where it passes through the limestone ridge of Blaisdon Edge, and the strata being 

 broken off, are diverted from their south-easterly course, a little to the west of south. At the 

 southern extremity of this ridge, is another and more deeply seated crack, through which the 

 Longhope brook, after having defiled for some miles along the outer zone of the Silurian Rocks, is 

 suddenly deflected, and escapes through the gorge to the Severn. From this point, the whole 

 system gradually tapers away into one low ridge, on the eastern side of Flaxley Park. 



Besides the shelly beds, principally reddish sandstone of the Caradoc formation, the hills of May 

 and Huntley contain still lower masses of very hard grit, some of which are singularly convoluted 

 and of peculiar structure. These may be well observed on the sides of the high road between 

 Huntley and Dursley Cross. (See section, PI. 36. f, 13.) In proceeding from the village of Hunt- 

 ley, the cuts on the north side of the road have laid bare these grits, which burst out abruptly from 

 the plain of New Red Sandstone in almost vertical strata, sometimes indeed converging round a 

 nucleus, and reminding the observer of the concretionary quartzose grits of the Cambrian rocks. 

 Occasionally they have almost a trappean aspect. Other hillocks, on the left of the road, consist 

 of hard dark grey sandstone and purple schist, folding round compact sandstone and fine-grained 

 greenish grit. The axis of these hillocks points 12° west of north, and the mantling strata dip 

 under coarse ferruginous grits almost conglomerates. Although the latter are clearly surmounted 

 by red sandstone containing Caradoc shells, yet as I could not observe a conformable junction, I 

 am not certain that the underlying masses strictly belong to the Lower Silurian Rocks. 



In following the axis of this ridge to the south, through the centre of Huntley Hill, 

 it is interesting to observe the termination of the Silurian rocks at Flaxley, where they 

 are reduced to a sharp point of Ludlow rock, not exceeding thirty paces in width, and 

 cut through by the high road from Mitchel Dean and Longhope to Gloucester and 

 Newnham. These are flaglike, greenish grey beds, in parts calcareous, probably be- 

 longing to about the middle part of the Ludlow formation, containing imperfect casts 

 of fossils, the strike being 10° or 12° to the west of north, as in the central mass of 

 May and Huntley Hills, and the dip 50° to 60° to the east. (See Map and PL 36. f. 14.) 

 This inclination is in an opposite direction to that of the Silurian strata of Blaisdon 

 Edge and Flaxley Park, thus marking the continuance of a true anticlinal ; whilst the 

 line of springs and ponds between the park and this detached hillock, marks another 



1 It was doubtless the appearance at this spot which lead Mr. Weaver to suppose, that the transition rocks 

 were generally unconformable to the Old Red Sandstone, a conclusion it was natural he should adopt, (as will 

 presently be shown) from the stronger evidences of their discordance exhibited at Tortworth, the district 

 he had selected as a type. (Geol. Trans., vol. i. p. 354. PI. 29, f. 4.) 



