Styles of mineralization in the Nautanen IOCG deposit
Nautanen is an IOCG (Iron Oxide Copper Gold) deposit located in northern Sweden, 10 km north-east of the town Gällivare in the county of Norrbotten. It was mined for copper for seven years in the early 1900´s and is presently explored by Boliden Mineral AB. The deposit sits within a package of shosh...
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Format: | Bachelor Thesis |
Language: | English |
Published: |
Luleå tekniska universitet, Geovetenskap och miljöteknik
2020
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-77837 |
Summary: | Nautanen is an IOCG (Iron Oxide Copper Gold) deposit located in northern Sweden, 10 km north-east of the town Gällivare in the county of Norrbotten. It was mined for copper for seven years in the early 1900´s and is presently explored by Boliden Mineral AB. The deposit sits within a package of shoshonitic andesites of the Porphyrite group. The rocks have been suggested to be formed in a continental back arc setting and are now hosting the major shear zone NDZ (Nautanen Deformation Zone). The deposit is characterized by an early peripheral magnetite – amphibole alteration and a main mineralization event of pyrite – chalcopyrite – potassium alteration. The majority of the copper- and iron- sulphides occur as veins and stockwork-network textures in strongly potassium-garnet altered schist. The gold occurs as Ag-Au or Ag-Au-Hg mineral grains of 1-30 µm. They are mostly found in fissures within pyrite and magnetite which indicates a later redistribution. The element association and tectonic setting fits well with the general IOCG model, while the mineralogy is not typical for IOCG deposits. |
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