Kongsberg MineralsVmposium 1999 Norsk Bergverksmuseum Skrift, 15,47-56 Minerals from the the Sulitjelma Copper Mines, North Norway Fred Steinar Nordrum The Sulitjelma Copper Mines (1891-1991) Mining history ranks as the largest mining enterprise in The first deposit discovered in SUlitjelma Norway in the 20th centrury. DUring the was found by a lapp, Mons Petter, about mining operations and also later, fine 1858. The Swedish consul Nils Persson mineral specimens have been collected in was granted a mining lease in 1886, and the district. after investigations and preliminary mining from 1887 he established a mining Introduction company, the Sulitelma Aktiebolag, in Copper has been mined in Norway for 1891. The Sulitjelma mines became the several hundred years, the first largest mining enterprise in Norway in the documented copper mine being the 20th century, with an estimate of 75 000 Verlohrne Sohn Mine in Kongsberg 1490. man years of labour. The largest number of Several types of copper ore deposits have employees was reached in 1913, been exploited, but the major ore type has amounting to 1 737. The company was been the Caledonian, massive, strata­ reorganized in 1933, under the name of bound sulphide deposits. Vigsnes, Stordl2J, AJS Sulitjelma Gruber, and from 1937 the Folldal, Rl2Jros, Ll2Jkken, and Grong are major shareholders were Norwegians. The other well-known ore districts with deposits mining operations ended June 28, 1991. of this type. In this paper, however, the Sulitjelma district will be focused on. It is Figur 1. Simplified geological map of the situated about 80 km east-southeast of the Su/itjelma area with the location ofthe most town Bodl2J in Nordland county. important sulphide deposits (after Cook et al. 1993). • Kjeldvatn Metadoleriles D FuruJund Group l~*fu Orebodies (projected) ~ Sulitjelma Ophiolite t:::j Furulund Granite :::~.::::::.::::::: ...... .. .. ..... .. 1::::1 Skaiti Supergroup ............................ .... .............................. .............................. .:::r~:: N ................................ :::'::'.. ................................ .. '/eI, ·_-Sulitjelma .............................. ............................ .. ............................... /::~:,:: ::.::~~,::: ...WfII!":~: ... 5km t 47 ........................ ........................ Kjeldvatn :. ....................... Sulitjelma was a very isolated mining Elmore processing plant was built in 1909. society, in a remote valley, about 35 km The first of three smelteries was built in from the nearest public road and the coast 1894, and the last one closed down in to the west, and 10 km from the Swedish 1987. The copper smeltery was the first border to the east. The transport took place one ever to be based on copper smelting partly by a railway line (built by the mining by electric power (Quale 1975). company) and partly by boats (on the lakes) from the coast. In the winter some Only about 900 people are now living in supplies were transported by horse Sulitjelma all the year. Many of the old wagons on the ice-covered lakes. The houses serve as holiday homes, while railway was completed in 1956. In 1972, others are used by organizations and after more than 80 years of mining, a road tourist enterprises focusing on wild life was finally finished, and the railway was activities. A small enterprise (Saulo) takes closed down. out drill cores of sulphide ore, using polished ore and brass to make different In the hills around Sulitjelma about twenty gift objects. There is also a small, nice five massive, stratabound copper deposits mining museum (founded in 1977), and a were prospected, and eighteen were part of the Giken mine is open to visitors by worked (see sketch map). The a mine train through the Grunnstoll adit. Jacobsbakken mine (1896-1968), the Since the smeltery closed down in 1987 a largest deposit, produced 4.5 million tons rapid return of vegetation has taken place. of sulphide ore; the Giken I mine (1892­ 1973), the second lagest, produced 3.2 Geology million tons. Altogether 26 million tons of The sulphide deposits are situated at the sulphide ore have been mined in the district contact between submarine basalts and (Ellingsen et al. 1996). overlying sediments of Upper Ordovicium The ore was processed and smelted to age. The deposits are interpreted to have blister copper in Suliljelma. The copper been formed by volcano-exhalative ingots contained about 99% copper and sedimentary processes at sea floor in a 600 grams of silver and 6-8 grams of gold fault-controlled basin during ocean closure. per ton. The mine for many years also The present sequence of basalts, gabbros, produced a zinc concentrate and a pyrite ultramafics and sheeted dykes has been concentrate. The smelting of the copper interpreted as a preserved ophiolite suite sulphide concentrates produced (as a part of an ancient sea floor considerable air pollution in the deep plate)(Boyle 1989). The Sulitjelma gabbro valley. Paint flashed off the houses after a has been dated to about 437 million years short time, and most of the vegetation died. (Pedersen et al. 1991). The rocks and Acidic, polluted water from the mines killed deposits have suffered strong regional the fish population in the lakes and the metamorphism and deformation. The river. SUlphide deposits are classified as The mining, processing and smelting belonging to the Cyprus type. took place in accordance with the most advanced technology, and some The sulphide deposits improvement of the processes were also The Sulitjelma district is about 100 km 2 in developed, e.g. the Knutsen converter in size. About 25 individual ore deposits with the smeltery (1902) which needed much a total sulphide mass of some 35 million less external energy as it used sulphur tons have been discovered. The sulphide from the ore as fuel. The world's largest bodies are tabular and elongated in shape, 48 reaching 1200 m in length and 300 m in Macroscopic minerals width. They rarely exceed 5 m in thickness, the average being about 2 m. Fine ore samples Massive pyritic ore (with some SUlitjelma is famous for its rich chalcopyrite, pyrrhotite, sphalerite and chalcopyrite (+ pyrrhotite) ore with a galena) (60-90% sulphides) accounts for at number of scattered, rounded pyrite least 80% of the total mass of sulphides crystals. Blocks of this ore type are found in (Cook 1996). many museums. The pyrite crystals are There is also some semi-massive usually around 1-2 cm, but may reach banded ore and disseminated ore, besides several centimetres. Most of this ore also some rich, remobilized pyrite­ comes from the Charlotta-Giken area. pyrrhotite-chalcopyrite ore and massive chalcopyrite ore. Pyrite On an average the mined ores contained Crystals of pyrite are widespread in the about 20% sulphur, 1.8% copper, 0.4% ores and the chlorite schists. Rounded zinc, 0.5 grams per ton of gold and 30 crystals loosened from chalcopyrite ore are grams per ton of silver. up to 10 cm in diameter. Pyrite in cavities Veins are also present, which Cook and in chlorite schists usually have sharp (1996) divides into two types: Chalcopyrite­ edges, and cubes up to 5-10 cm have been pyrrhotite ore veins with the gangue collected. Cube is by far the most common minerals quartz, actinolite, titanite and habitus, but also pentagon-dodecahedrons kyanite, and sUlphate-bearing veins with and (in Ny-Sulitjelma) octahedrons are anhydrite, quartz, calcite and minor present. Some cubic pyrite crystals are celestine and barite. elongated. Some pyrite porphyroblasts A chemically and mineralogically distinct have surrounded other pyrite crystals zone of hydrothermal alteration surrounds during growth. The cobalt content of pyrite each sUlphide body, containing chlorite and has been measured within the range 180­ albite and sometimes biotite andlor 2400 ppm. actinolite. Arsenopyrite Ore minerals Arsenopyrite crystals, often twinned, are The sUlphide ore consists mainly of commonly found as porphyroblasts up to 3 pyrite, pyrrhotite, chalcopyrite and mm in pyritic ore (Cook 1996). They have a sphalerite. Galena, arsenopyrite, cubanite, generally low content of cobalt and a quite molyb-denite and tetrahedrite are present low content of nickel (n.d. to 0.75%). In in minor amounts. Jakobsbakken, porphyroblasts of cobaltian Investigations with reflected light arsenopyrite ("danaite") crystals up to 2 cm microscopy and electron microprobe have occur in remobized ore or ore veins rich in yielded a large number of accessory ore galena, chalcopyrite, and sulphosalts. minerals (Cook 1996). They are almost Cook (1996) reports a cobalt content in the exclusively found in the rich, remobilized range 0.86 - 2.51 weight %. These crystals ores and the veins. These minerals are were first decribed by Stelzner (1891) and usually only visible in microscope by high Fletcher (1904), and later by Ramdohr magnitude and are merely listed here. (1938). Occasionally numerous, Many contain antimony, bismuth, lead, idiomorphic arsenopyrite crystals up to 1­ silver, gold andlor tellurium (Tabel 1). The 1.5 em in length have been found in association between antimony and chlorite rich layers (H.Chr. Olsen pers. goldlsilver is significant (Cook 1992). comm.1998). 49 Quite large crystals have also been clusters of a few crystals, but often as observed from other deposits, e.g. sheeted aggregates occurring at pocket Charlotta and Giken. walls. The crystal size is up to 3 cm in length and 1.3 cm in thickness, and the Chalcopyrite and pyrrhotite colour is white to watercoloured.