L. Richardson — The Inferior Oolite of Bredon Hill. 513 



only flint pebbles from the Chalk, while the high-level gravels 

 which rest on the Bagshot series contain besides flint many pebbles 

 derived from the Lower Greensand. 



Where, however, the exposure is by a fault scarp the whole of 

 the beds exposed in the scarp will contribute to the first-formed 

 derivative conglomerates. The absence of detritus of the Basement 

 Carboniferous from the Lower Brockram shows that the basement 

 beds were not exposed in early Permian times, but a movement of 

 the fault exceeding the thickness of the Penrith Sandstone brought 

 the lowest members of the Carboniferous series above the surface 

 at the time of the deposition of the Upper Brockram 



X. — On the Sequence of the Inferiok Oolite Deposits at 



Bredon Hill, Worcestershire. 



By L. EicHARDSON, F.G.S. 



THE correct sequence of the Inferior Oolite deposits at this locality 

 has always been a matter of uncertainty. This is due partly 

 to the disturbed state of the oolite, partly to the scarcity of fossils. 

 On Bredon Hill only the four lowest subdivisions of the Inferior 

 Oolite series are preserved. In the Cotteswold Hills around 

 Cheltenham they are, in descending order, the Lower Freestone, 

 Pea -grit. Lower Limestone, and sandy beds characterized by 

 a very distinctive ammonite, Tmetoceras scissum — the last being 

 the sandy ferruginous limestones of Witchell. Professor Hull did 

 not recognize the Pea-grit at Bredon, but stated that its most 

 northern extension was at Netting Hill.^ In 1863, however, 

 Dr. Holl rectified this error, and remarked that its non-existence 

 here was only true as regards its pisolitic structure.^ Above 

 Elmley Lodge that author noticed masses of limestone crowded with 

 fragments of the spines and plates of Echinoderms, as well as numerous 

 specimens of Bryozoa, and Terehratula pUcata. Below the brow of 

 the eastern extremity of the hill, above Ashton-under-Hill, Dr. Holl 

 obtained Bhynchonella cynocephala in blocks of hard limestone, but 

 was unable to find the bed in situ or to offer any suggestion as to 

 its probable stratigraphical position. 



One mile north-west of Overbury Church is a large quarry, and 

 although the strata here — as in the rest of the hill — are very much 

 disturbed, it is possible to construct the sequence and also to obtain 

 approximately the thickness of the several subdivisions. The 

 sequence may be obtained by a study of the section afforded on the 

 east side of the quarry. 



The continuity of the sequence of the deposits is interrupted by 

 a fault. On the north side about 12 feet of Lower Freestone is 

 exposed, resting upon the equivalent of the Pea-grit. The top beds 

 of this Pea-grit equivalent consist of hard yellowish limestones full 

 of fragments of the spines and plates of Echinoderms. Capping the 

 projecting mass of rock — separated from the east face of the quarry 



^ Mem. Geol. Surv. : "Geology of the Country around Cheltenham" (1857), 

 p. 33. Nottiug Hill is locally known as Nottingham Hill. 

 ^ Quart. Journ. Geol. Soc, vol. xix (1863), p. 315. 



DECADE IV. VOL. IX. NO. XI. 33 



