Iron Ore at Limeslade and Dr’s Mine, Mumbles, near Swansea.
12th November 2017.
The fault and mine are on and above the beach at Limeslade Bay, west of Swansea, on the eastern most corner of the Gower Peninsula. Bracelet Bay is just to the east.
Buy a vanilla ice cream from the famous Forte's Cafe and look over into Limestone Bay itself, which was formed as the result of erosion along a significant fault, which extends from the bay, over Mumbles Hill, and the Langland Bay Anticline, emerging near to the Mumbles Yacht Club.
The fault zone is characterized by the presence of often red stained crystalline calcite and haematite. It has always been assumed that the red colour is derived from an earlier unconformable cover of continental Triassic red beds, as can be seen at outcrop to the east, in places such as Penarth and Sully.
When I was a boy we used to fish for bass, with the rising tide, in the gullies along this part of the coast. Dr's Mine, was a favourite spot, close to my home. It is about a kilometer to the west of Limeslade, between Jinny's Gut and Lambs Well Bay, before Rotherslade and Langland Bays. As at Limeslade there is another small bay excavated along a fault zone. Looking up the beach towards the cliff you will note a larger cave to the left and to the right the fault zone, which leads up to a tunnel partly eroded by the sea and presumably partly hacked out by miners long ago. As at Limeslade the fault zone contains fault breccias, white and red coloured crystalline calcite and blood red haematite. Getting to this bay is a bit tricky and should only be done at low tide.
Dr's Mine bay contains interesting exposures of Quaternary sediments, including the Patella raised beach, a limestone breccia 'head' and polymictic, often mud supported, conglomeratic glacial out-wash, above the main Carboniferous Limestone. Pebbles and boulders in the beach are derived from the local limestone, the fault zone and also Late Carboniferous and Devonian sandstones eroded out from the glacial out-wash and presumably derived from exposures to the north. Occasionally you may find more exotic rocks, which were probably sourced from ballast jettisoned from a stream ship, SS. Tyne, which was grounded near bye, one hundred years ago.
Half a kilometer further to the west is Rotherslade Bay, with it's stack, locally known as the 'big rock'. In one corner of the bay there is another fault zone, which could also have been mined. A cave, which is now bricked up, once yielded elephant bones.
Some have suggested that the mine at Limeslade was initially excavated during Roman times, but I always wondered if this inference was based on direct evidence or analogy with similar mines, in places such as the Mendips and the Great Orme. New evidence from an archaeological excavation, of a midden, on nearby Mumbles Hill though does suggest, at least, a small scale Roman presence, in the third century AD, possibly associated with quarrying or mining. Further evidence of the Roman presence is indicated from pieces of mosaic excavated. at nearby Oystermouth Parish Church.
There is some evidence that the iron in this mines was used even earlier from the red staining of the ritually buried remains of the Paviland 'Lady', now regarded as male, discovered in a cave near to Port Eynon Bay and most recently dated as 33,000 BP.
I would be interested to know whether small scale operations such as those at Limeslade and Dr's Mine were for the extraction of ore for making iron and or ochre for paint.
………and am always interested to learn more about this fascinating and beautiful stretch of coastline......
ROBERT MEYRICK