Ballynoe mine (Magcobar mine), Silvermines District, Tipperary County, Munster, Irelandi

Regional Level Types
Ballynoe mine (Magcobar mine)	Mine
Silvermines District	Mining District
Tipperary County	County
Munster	Province
Ireland	Country

Opencast barite mine, now abandoned and flooded. Extensive dumps with large quantities of rotting pyrite. Dolomite and calcite vugs contain various crystalline sulphides but are hard to find.

Immediately underlying the strongest base-metal and barite mineralisation at Silvermines, the Muddy Reef Limestone is extensively replaced by chert in the uppermost part of the succession, and black chert lenses up to 5 m thick are of common occurrence below the barite horizon. A similar thickness of chert is reported underlying the ‘Upper G Zone’ orebody.
The Muddy Reef Limestone is generally capped by an irregular development of green argillite, the “Green Shale” of previous authors, which also interdigitates with the barite horizon. The thickest development of this shale is found to occur in minor surface depressions at the top of the Muddy Reef Limestone, ranging from a few cm up to a maximum of around 1.2 m. Slump structures are evident in the thicker shale lenses and rare, angular micro-fragments of bioclastic limestone are sometimes incorporated into the slumped argillite. That based on its constituent mineralogy the green argillite may be divided into two facies: (a) a chlorite–illite–quartz shale ± barite, and (b) a siderite–chlorite–illite–quartz shale.
The basal Unit 1, typically 1–2 m in thickness, can be sub-divided into the following types: (1a) barite breccia; (1b) banded haematite–barite with massive jasper; (1c) replacement of the footwall by barite and pyrite.

Other Regions, Features and Areas containing this locality

References