UBSS Proceedings 19(1)
Content Summary
The Gough's Cave System: Exploration since 1985 and a reappraisal of the geomorphology
1991
Authors: Farrant, A.R.
The recent explorations in Gough’s cave are described including the discovery of the main river passage, the alternative dry route into Lloyd Hall and the passages at the top of the Fonts. The cave is a complex resurgence system, developed on several levels along a minor drag fold, whose axial trend is 120°, parallel to the strike. Strong north/south jointing is well developed and has a strong influence on cave development. A modified scheme of evolution is presented, which is contrasted with that of previous authors who suggest that there was only one input to the system via the Boulder Chamber. Recent digging in the cave and the exploration of the River Cave show that this is not the case and at least three other inlets existed including Damocles Rift, Makin’ Progress and the River Cave. Four major still-stands of the water table deduced from passage morphology are proposed, the highest at or above 105 m AOD in Great Oones Hole/Long Hole, one at 70-75 m (Damocles Rift/Sand Chamber level) another one at c. 45 m (Boulder Chamber/Western Creep level) and the present water table at 23 m AOD in the River Cave. These are related to the evolution of the cave system. The modern active conduit exhibits strong structural control, forming a series of deep phreatic loops parallel to the dip and a horizontal water table passage along the strike.
A catalogue of all the extant and reasonably recorded lost Roman-British material derived from the caves of Cheddar Gorge is presented. The vast majority of finds are from the third and fourth century. The smaller and relatively inaccessible caves (Sun Hole, Soldier’s Hole) were used as hideaways, but the larger caves (Gough’s Old Cave, Long Hole) saw domestic occupation and possibly metalworking activities.
Preliminary report on a recent collection of stone artefacts from the '100 foot Terrace' at Abbots Leigh, Avon
1991
Fieldwalking has yielded a considerable collection of stone artefacts from Chapel Pill Farm, Abbots Leigh, a site previously described by Lacaille (1954). The collection appears to be derived wholly from locally available material (predominantly chert) and despite differential preservation (some pieces are abraded while others are fresh) appears not to be transported other than by solifluction. Unlike other collections containing Lower Palaeolithic artefacts, a very wide range of tools is present including burins, awls, scrapers, choppers, handaxes and hammerstones.
The habitat and origin of lead ore in Grebe Swallet Mine, Charterhouse-on-Mendip, Somerset
1991
Authors: Stanton, W.I.
Undisturbed deposits of lead ore were found when Grebe Swallet, an old mine at Charterhouse, was reopened in 1982. Abraded lumps of galena are present in a wide variety of sedimentary matrices filling voids in the Carboniferous Limestone. The deposits are residual orebodies derived from primary galena veins that once existed at levels above the present limestone plateau of the Mendip Hills. Formed in association with neptunian dykes, the primary lead veins were fragmented and concentrated as the plateau surface was lowered 90 metres or more by dissolution over a very long period of time. It is argued that all the lead orefields of the Mendip high plateau are likely to have consisted of secondary residual deposits similar to those at Charterhouse.
Repeat tracer tests using fluorescent dyes were made on four swallets in the Carboniferous Limestone Seven Springs cathment, East Mendip. Downhead Swallet feeds a predominantly vadose conduit, with a major distributary which underflows the Seven Springs but does not feed Holwell Spring. Dairyhouse Slocker is tributary to the conduit below this distributary, but the Bottlehead conduit is independent and feeds only the Main Spring. Dewatering at Torr Quarry has caused a change in the function of the phreatic conduit from Heale Swallet, which previously was tributary to the main Downhead conduit. The conduit has not been directly intersected by quarrying but diffuse leakage induced by the steepened hydraulic gradient towards the quarry captures all the flow. The Bottlehead Slocker conduit is similarly affected, with leakage being large at low flow, but insignificant at high flow. The Downhead Swallet conduit is affected least by quarry dewatering, because of its vadose nature and greater distance from the quarry. Nevertheless movement of water from the conduit into the diffuse flow zone does occur, particularly during periods of active swallet recharge.
Since the publication of the previous Cave Notes: County Clare (Boycott and Wilson, 1986) there have been further discoveries in County Clare which are documented here.
Authors: Mullan, G.J.