EXPLORATION AND MINING DIVISION IRELAND ZINC • LEAD • COPPER • GOLD • SILVER • BARYTES • GYPSUM • COAL • DOLOMITE • TALC THE “TOP 555”5” DEPOSITS Department of Communications, Marine and Natural Resources The Mining Heritage Ireland is richly endowed with a diversity of mineral deposits, with a mining heritage extending for over 4,000 years. Although much of the information is shrouded in time, enough remains to show that the country was firmly established as a significant metal producer at several distinct stages in history. During the Final Neolithic/Early Bronze Age (c.2400-1500 B.C.) Irish mines were an important source of copper, while alluvial gold may have been used for some of the abundant gold ornaments of this period. The 16th and 17th centuries were a time of extensive iron production, while the 19th century saw continuous copper, lead and silver output for over 70 years, as well as a “gold rush” around the start of the century. And finally, the period since the 1960s have seen Ireland enjoy the status of a world-ranked producer of zinc, lead and barite, and become one of the most promising exploration territories in Europe. Historical Record The first evidence of mineral deposits as an important resource in Ireland after the Stone Age is to be found in Bronze Age times (c.2300-500 B.C.) or a little earlier. Recent research has established that primitive copper mines were worked in SW Ireland in the period c.2400-1500 B.C., with the bulk of those dated during the period c.1700-1500 B.C. These mines were located both in mineralized quartz veins and sedimentary copper beds, as workings which rarely exceeded 10m in depth. Near-site smelting is likely, and the copper production made Ireland an important European producer of bronze axes and other utilitarian products during this time. The subsequent decline was probably due to the exhaustion of accessible mineralization. It is also likely that gold was first discovered during the Bronze Age, Bronze Age copper mine at Muckross, Killarney, Co. Kerry. since there is reference to gold being found in c.1600 B.C. By the end of the 1880s however, a bleak period of some 70 and worked at a site to the south of Dublin. years was to ensue. The exhaustion of deposits, falling metal prices and the lack of new discoveries saw the virtual Few records remain of mining activity prior to the major cessation of metal mining. Up to the 1950s the only mining period of mining in the 19th century. Sparse texts attest to of note was a period of bauxite production in Northern iron working at Avoca in the 2nd century, to iron and Ireland, pyrite for sulphur from Avoca, and phosphate from copper mines in the 9th century, alum mining in the 12th the west of Ireland, reflecting economic demand during the century and lead-silver workings and copper mining war years, barite from Benbulben (1942-1960) and gypsum around 1500. Better information exists for the 16th and mining from the Kingscourt area from 1936 onwards. Coal 17th centuries however, which were marked by widespread mining continued from the Arigna, Rossmore and iron production. Although iron ores were probably mined Ballingarry areas from thin seams, but output otherwise and smelted from shortly after the Bronze Age (500 B.C.), largely consisted of limestone for agricultural use and Irish production did not rise to prominence until this time, materials for the Irish construction industry. when iron became an important export to England. The ores worked were gossans from Avoca, carbonate ore The stage however had been set for the finest period in Irish (‘ironstones’) from the coalfields, haematite, and the mining history. A comprehensive Minerals Development widespread ‘bog iron’ ore. As charcoal sources were Act (1940), followed by significant tax measures in the 1956 exhausted the industry declined. The last charcoal furnace Finance Act, had a catalytic effect on mineral exploration closed in 1765. Lead and silver were also mined in the 17th by attracting a number of Canadian exploration companies century at several locations (e.g. Silvermines). to the country. Encouraged by the State discovery of economic reserves at the lead-zinc deposit in Lower The flowering of the metal mining industry in the late 18th Carboniferous rocks at Abbeytown (in production from and 19th centuries was triggered by the needs of the 1950-1962), a surge of exploration focused in this Industrial Revolution in Britain. Copper mining boomed in stratigraphical level. Early confirmation of the existence of SW Ireland, especially at Allihies, but there was considerable significant mineralization came with the discovery of the lead, copper (e.g. Avoca) and silver mining elsewhere, with Ballyvergin copper deposit in 1957, followed by the almost every coastal county having at least one mine, based Tynagh zinc-lead-silver orebody in 1961. It was the on high-grade low-tonnage vein deposits (e.g. Bunmahon). discovery of this latter deposit, in a geological setting which This period also saw the main phase of coal mining had not previously produced any significant mineralization, (Rossmore and Ballingarry areas) and slate quarrying as well that set off a chain of discoveries (see Table). In 1962 the as pyrite from Avoca and manganese and barite production Silvermines zinc-lead orebody was discovered; this was from southern Ireland, with mining employment at peaks followed by the world-class Ballynoe barite deposit, in its never to be reached again. Fortunes were made and lost, not time the fifth largest barite producer in the world, and in least during the “gold rush” between 1795 and 1830 at the 1964 the Gortdrum copper-silver-mercury deposit was Gold Mines River, where an estimated 7-9,000 oz of gold found. All of these became profitable mines. was extracted from alluvial gravels. “Top 55” Commodity List Base Metal Deposits Gold Deposits Industrial Minerals (Incl. Lignite) Abbeytown (Zn, Pb) Bohaun Ballymoney, Aclare (Li) Carnew N. Ireland (Lignite) Aherlow (Cu, Ag) Cavanacaw, N. Ireland Ballynoe (Barite) Allihies (Cu) Clontibret Benbulben (Barite) Avoca (Cu) Cregganbaun Bennettsbridge (Dolomite) Ballinalack (Zn, Pb) Curraghinalt, N. Ireland Clonakilty (Barite) Ballyvergin (Cu) Gold Mines River Crumlin, N. Ireland (Lignite) Bunmahon (Cu) Inishturk Glangevlin (Gypsum) Carrickittle (Zn, Pb) Kildare Kedrah (Dolomite) Charlestown (Cu) Kilgeever Kilbreckan (Calcite) Courtbrown (Zn, Pb) Kilmacoo Kilroot, Derrykearn (Zn, Pb) Lecanvey N. Ireland (Salt) Duncormick (Zn, Pb) Kingscourt (Gypsum) Galmoy (Zn, Pb) Portroe (Slate) Gortdrum (Cu, Ag, Hg) Sandy Braes, Harberton Bridge (Zn, Pb) N. Ireland (Perlite) Inishannon (Zn, Pb) Tomduff (Andalusite) Keel (Zn, Pb, Barite) Westport (Talc) Lisheen (Zn, Pb) Mallow (Cu, Ag) Moyvoughly (Zn, Pb) Murvey (Mo) Navan (Zn, Pb) Newtown Cashel (Zn, Pb) Oldcastle (Zn, Pb) Silvermines (Zn, Pb) Tatestown (Zn, Pb) Tynagh (Pb, Zn, Cu, Ag, Barite) Upper Carboniferous & Younger Lower & Middle Carboniferous Devonian N Lower Palaeozoic Dalradian (Late Proterozoic / Cambrian) ■ Ballymoney Pre-Dalradian DERRY Lignite Granite Sandy Braes ■ Curraghinalt Perlite ■ Kilroot Au ▲ Crumlin Salt ■ Lignite ▲ BELFAST Cavanacaw Au Benbulben ■ Barite ■ Glangevlin ▲ Abbeytown Gypsum Clontibret Zn, Pb Arigna■ Au Coal Kingscourt Gypsum ■ Lecanvey Charlestown Kilgeever Au ■ Westport ▲ Cu Au▲ Talc Oldcastle ▲ Keel ▲ Zn, Pb Inishturk Cregganbaun Zn, Pb, Barite Tatestown Au Au Zn, Pb ▲ Newtown Cashel Ballinalack Navan Bohaun Zn, Pb Zn, Pb Zn, Pb Au Moyvoughly Zn, Pb Murvey DUBLIN Mo GALWAY Harberton Bridge Zn, Pb Kish Basin Coal Tynagh Kildare Pb, Zn Cu, Ag, Barite Au Kilmacoo Silvermines Derrykearn Ballyvergin Au▲ Zn, Pb Zn, Pb Rossmore Cu Portroe ■ Galmoy Gold Mines ▲ ■ ■ Coal Kilbreckan Slate Zn, Pb ■ River Au Avoca Calcite Ballynoe Bennettsbridge Cu LIMERICK Aclare Barite Dolomite ▲ Lisheen Li Gortdrum ■ Carnew Courtbrown Zn, Pb ■ ■ Cu, Ag, Hg Ballingarry Tomduff Au Zn, Pb Carrickittle Coal Andalusite Zn, Pb Aherlow ■Kedrah Cu, Ag Dolomite Duncormick Zn, Pb Mallow Bunmahon Cu, Ag Cu CORK City Active Inishannon Disused mine Zn, Pb Base metal deposit ■ Allihies ▲ Gold deposit Cu Clonakilty ■ Undeveloped gold deposit Barite 0101 20304050 km Industrial mineral deposit ■ Coal deposit (some intermittently worked) EMD 2003 Data Availability A substantial amount of information is available from earth science information and advice. Relevant data two Divisions, both within the Department of sources include: Communications, Marine and Natural Resources. • Paper geological maps at various scales. 1:100,000 scale maps with selected mineral • Exploration and Mining Division localities described in associated reports. The Exploration and Mining Division (EMD) deals with 1:25,000 and 1:10,560 scale ms maps with minerals policy, the administration of the State mining outcrop data. Smaller-scale mineral deposit and prospecting system and minerals promotion. The and metallogenic maps of Ireland. • Digital maps. Seamless geological map, based Division comprises both administrative and technical on 1:100,000 scale paper maps. All outcrops on staff, and is a key reference point with a full support 1:10,560 scale ms maps have been digitised. service on all regulatory matters, including: • Mineral Exploration Open File. Assessment reports submitted by exploration companies • Legislative provisions under the terms of their Prospecting Licences • Reference information on the geographical and released upon surrender of the licence or areas of all prospecting licences six years after lodgement, whichever