|CLIFTON (AVON GORGE)||University of Bristol
|The , which is a former quarry, is on the East bank of the River Avon about 2 miles north-west of the City centre and about 1 mile south-east of Sea Mills station. If you visit it by car it is easier to approach the site from the North and park in the first lay-by you come to.|
|The rocks here are the
Lower Carboniferous Black Rock Limestone and Black Rock Dolomite. Brachiopods,
corals and crinoids make up the fauna of these rocks, which can be divided
in to three assemblages.
The Lower or Zaphrentites delanouei biozone contains the brachiopods Cleiothyridina glabristria, Dictyoclostus multispiniferus, Pugilis vaughani, Rhipdomella michelini, Rugosochonetes vaughani and Syringothyris cuspidata cyrtorhynca and the corals Z. delanouei, Fasciculophyllum omaliusi and Syncoelasma clevedonensis.
Corals including Caninophyllum patulum, Caninia cornucopiae, Cyathaxonia cornu, Cyathoclisia tabernaculum, F. densum and Syncoelasma konincki first appear in the Middle or C. patulum biozone.
The type fossil of the Upper biozone is the coral Siphonophyllia cylindrica. Brachiopods found in this biozone include Eomarginifera derbiensis, Megachonetes magna, Pustula pustuliformis, P. pyxidiformis, Syringothyris elongata and Schuchertella wexfordensis.
|There were a number of
large boulders lying at the base of the outcrop, but little in the way
of easily collectable scree. The in situ fossils visible at eye level or
below were highly fragmented, suggesting they were deposited in a high
About 100m south of this quarry is another accessible outcrop which exposes more of the Black Rock Dolomite, overlain by Gully Oolite and Then Clifton Down Mudstone. However this area doesn't seem to be fossiliferous.
Kellaway, G. A. & Welch F. B. A., 1993. Geology of the Bristol district, pgs 28-31. HMSO, London.