Galmoy Mine, Johnstown, Co. Kilkenny, Ireland
|Latitude & Longitude (WGS84):||52° 48' 19'' North , 7° 35' 49'' West|
|Latitude & Longitude (decimal):||52.80528,-7.59722|
|Köppen climate type:||Cfb : Temperate oceanic climate|
A lead-zinc underground mine.
The orebody, in Lower Carboniferous rocks, was discovered in the 1960's when significant soil geochemical anomalies were found. More surveys were conducted in the 1980's and finally, mineralization was found.
The mine began production in 1997 and various satellite orebodies have been found.
The ore is breccia-hosted and forms generally stratabound lenses of predominantly massive sulphides consisting of sphalerite, Ag-bearing galena, and pyrite/marcasite.
'Room and pillar' extraction methods are used and unfortunately backfilling as well, making collecting difficult.
Requests to the geology department for specimens, or even access to the mine, have been consistently ignored or refused on the grounds that mineral "specimens are the property of the company and cannot be allowed off site", a policy strongly defended by the chief geologist. They seem to have had no interest in preserving their natural mineralogical heritage for future generations.
The mine closed in summer 2009 but reopened shortly after to permit removal of some remaining high-grade ore for processing at the nearby Lisheen mine. Of the three modern Irish zinc mines (Galmoy, Lisheen, and Tara), Galmoy was the best for vugs and crystallised material, but for the aforementioned reasons, almost nothing has been saved. The few pieces obtained from employees indicate that this mine may have been the greatest Irish mineralogical treasure trove since Silvermines.
36 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Permian - Carboniferous|
252.17 - 358.9 Ma
|Carboniferous-Permian sedimentary rocks|
Balassone, G., Rossi, M., Boni, M., Stanley, G., and McDermott, P. (2008) Mineralogical and geochemical characterization of nonsulfide Zn–Pb mineralization at Silvermines and Galmoy (Irish Midlands). Ore Geology Reviews 33, 168-186.
Barrie, C.D., Boyce, A.J., Boyle, A.P., Williams, P.J., Blake, K., Wilkinson, J.J., Lowther, M., McDermott, P., and Prior, D.J. (2009) On the growth of colloform textures: A case study of sphalerite from the Galmoy ore body, Ireland. Journal of the Geological Society 166(3), 563-582.