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Ystrad Mine (Silurian Mine), Betws Garmon, Gwynedd, Wales, UKi
Regional Level Types
Ystrad Mine (Silurian Mine)Mine
Betws GarmonCommunity
GwyneddCounty
WalesCountry
UKCountry

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PhotosMapsSearch
Latitude & Longitude (WGS84):
53° 5' 36'' North , 4° 10' 50'' West
Latitude & Longitude (decimal):
UK National Grid Reference:
SH540574
Type:
Köppen climate type:
Nearest Settlements:
PlacePopulationDistance
Llanberis1,844 (2017)4.4km
Llanrug1,916 (2017)6.1km
Bontnewydd951 (2017)6.4km
Talysarn1,086 (2017)6.8km
Groeslon880 (2017)6.9km
Mindat Locality ID:
5169
Long-form identifier:
mindat:1:2:5169:2
GUID (UUID V4):
0
Other/historical names associated with this locality:
Caernarvonshire


The largest of the Gwynedd iron mines, all of which exploited sedimentary deposits precipitated as nodules within a cleaved mudstone, the Nant Ffrancon formation, that occurs widely across this area of north Wales.

The workings, variously known as Ystrad Mine or Silurian Mine run in a series of 8 large chambers in long gash for about 700 yards up the hillside of Moel Eilio at Betws Garmon ending on the 700ft contour. A smaller adjoining mine, Garregfawr Mine lies on the same vein or bed of ore as does the largely unsuccessful Tyddynbach Mine. A small surface trial, Cwm Buchan Mine, was located on a separate ore body about a mile to the south east of Betws Garmon on the slope of Craig Cwm Buchan.

Although instructions were first issued to sell leases for iron ore mining on the property in 1891, the mine was not worked until 1909. Until about 1912 the initial workings were at surface, thereafter the majority of the workings were underground. Mining peaked in 1917 when 35 men were employed ungerground and 8 men above ground. The mine closed in 1919.

The property leases were controlled by the Betws Garmon Iron Ore Company (1909-12), which evolved into the Phosphoric Iron Ore Company Ltd (1912-13). In 1913 the company was wound up and the lease obtained by the Silurian Iron Ore Company Ltd (1913-19), which also controlled other Caernarvonshire iron mining interests.

Although easily worked, the mine having no water problems and the undergroung workings not requiring timbering, the ore, like all of the Gwynedd iron mines had a high silica content which rendered it unattractive to distant ironmasters and which contributed to the mine's ultimate failure.

The site still shows the remains of an incline and winding houses.

Ref: Caernarvonshire Iron Ore, Jeremy S Wilkinson, British Mining No. 78, Memoirs 2005, Northern Mines Research Society.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


3 valid minerals.

Detailed Mineral List:

Allophane
Formula: (Al2O3)(SiO2)1.3-2 · 2.5-3H2O
Siderite
Formula: FeCO3
References:
Stilpnomelane
Formula: (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
References:

List of minerals arranged by Strunz 10th Edition classification

Group 5 - Nitrates and Carbonates
Siderite5.AB.05FeCO3
Group 9 - Silicates
Allophane9.ED.20(Al2O3)(SiO2)1.3-2 · 2.5-3H2O
Stilpnomelane9.EG.40(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O

List of minerals for each chemical element

HHydrogen
H Allophane(Al2O3)(SiO2)1.3-2 · 2.5-3H2O
H Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
CCarbon
C SideriteFeCO3
OOxygen
O Allophane(Al2O3)(SiO2)1.3-2 · 2.5-3H2O
O SideriteFeCO3
O Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
NaSodium
Na Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
MgMagnesium
Mg Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
AlAluminium
Al Allophane(Al2O3)(SiO2)1.3-2 · 2.5-3H2O
Al Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
SiSilicon
Si Allophane(Al2O3)(SiO2)1.3-2 · 2.5-3H2O
Si Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
KPotassium
K Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
CaCalcium
Ca Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O
FeIron
Fe SideriteFeCO3
Fe Stilpnomelane(K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O

Other Regions, Features and Areas containing this locality

British and Irish IslesGroup of Islands
Eurasian PlateTectonic Plate
EuropeContinent
UK

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