Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden
The Paleoproterozoic Falun Zn-Pb-Cu-(Au-Ag) pyritic sulfide deposit in the Bergslagen ore district, Sweden, is enveloped by hydrothermally altered rocks metamorphosed to the lower amphibolite facies. Immobile-element ratios suggest that the alteration precursors were volcanic rocks of mainly rhyolit...
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Luleå tekniska universitet, Geovetenskap och miljöteknik
2017
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-5137 https://doi.org/10.5382/econgeo.2017.4504 |
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ftluleatu:oai:DiVA.org:ltu-5137 2023-05-15T16:13:06+02:00 Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden Kampmann, Tobias Christoph Jansson, Nils Stephens, Michael Majka, Jarosław Lasskogen, Jonas 2017 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-5137 https://doi.org/10.5382/econgeo.2017.4504 eng eng Luleå tekniska universitet, Geovetenskap och miljöteknik Uppsala universitet, AGH University of Science and Technology, Mickiewicza Boliden Mineral AB Economic geology and the bulletin of the Society of Economic Geologists, 0361-0128, 2017, 112:5, s. 1111-1152 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-5137 doi:10.5382/econgeo.2017.4504 ISI:000426874300005 Scopus 2-s2.0-85021135933 Local 329616f3-a1ac-49e9-8cfe-bee49ce58aa3 info:eu-repo/semantics/openAccess Geology Geologi Article in journal info:eu-repo/semantics/article text 2017 ftluleatu https://doi.org/10.5382/econgeo.2017.4504 2022-10-25T20:54:02Z The Paleoproterozoic Falun Zn-Pb-Cu-(Au-Ag) pyritic sulfide deposit in the Bergslagen ore district, Sweden, is enveloped by hydrothermally altered rocks metamorphosed to the lower amphibolite facies. Immobile-element ratios suggest that the alteration precursors were volcanic rocks of mainly rhyolitic to dacitic composition. Least altered examples of these rocks plot along magmatic fractionation trends outlined by late- to post-ore feldspar-phyric metadacite dikes and post-ore granitoid plutons, consistent with a comagmatic relationship between these calc-alkaline, coeval (<10-m.y.) suites. Dolomite or calcite marble, as well as diopside-hedenbergite or tremolite skarn, form subordinate but important lithologic components in the hydrothermally altered zone. Marble occurs as fragments in the massive pyritic sulfide mineralization, suggesting that at least some mineralization formed by carbonate replacement. Mass-change calculations suggest that the hydrothermally altered volcanic rocks gained Mg and Fe and generally lost Ca, K, and Na. Proximal, quartz-anthophyllite-rich altered rocks additionally gained Si, whereas several types of biotite-rich altered rocks lost this element. These mass changes along with mineral chemical data for anthophyllite, biotite, cordierite, and garnet, and the common occurrence of quartz indicate that chloritization, sericitization, and silicification were the dominant premetamorphic alteration styles. A zonation from distal sericitized and silicified volcanic rocks to intermediate sericitized rocks, partly overprinted by chloritization (Mg-rich chlorite), and proximal siliceous and intensely chloritized (Fe-rich chlorite) rocks has been identified. Furthermore, mass changes in more peripheral parts of the altered zone toward the southeast of the deposit suggest that the alteration weakens gradationally toward the volcanic and subvolcanic rocks surrounding the deposit. These patterns represent vectors toward mineralization. Intensely chloritized rocks, largely represented by a ... Article in Journal/Newspaper Fennoscandian Luleå University of Technology Publications (DiVA) Economic Geology 112 5 1111 1152 |
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Luleå University of Technology Publications (DiVA) |
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English |
topic |
Geology Geologi |
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Geology Geologi Kampmann, Tobias Christoph Jansson, Nils Stephens, Michael Majka, Jarosław Lasskogen, Jonas Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
topic_facet |
Geology Geologi |
description |
The Paleoproterozoic Falun Zn-Pb-Cu-(Au-Ag) pyritic sulfide deposit in the Bergslagen ore district, Sweden, is enveloped by hydrothermally altered rocks metamorphosed to the lower amphibolite facies. Immobile-element ratios suggest that the alteration precursors were volcanic rocks of mainly rhyolitic to dacitic composition. Least altered examples of these rocks plot along magmatic fractionation trends outlined by late- to post-ore feldspar-phyric metadacite dikes and post-ore granitoid plutons, consistent with a comagmatic relationship between these calc-alkaline, coeval (<10-m.y.) suites. Dolomite or calcite marble, as well as diopside-hedenbergite or tremolite skarn, form subordinate but important lithologic components in the hydrothermally altered zone. Marble occurs as fragments in the massive pyritic sulfide mineralization, suggesting that at least some mineralization formed by carbonate replacement. Mass-change calculations suggest that the hydrothermally altered volcanic rocks gained Mg and Fe and generally lost Ca, K, and Na. Proximal, quartz-anthophyllite-rich altered rocks additionally gained Si, whereas several types of biotite-rich altered rocks lost this element. These mass changes along with mineral chemical data for anthophyllite, biotite, cordierite, and garnet, and the common occurrence of quartz indicate that chloritization, sericitization, and silicification were the dominant premetamorphic alteration styles. A zonation from distal sericitized and silicified volcanic rocks to intermediate sericitized rocks, partly overprinted by chloritization (Mg-rich chlorite), and proximal siliceous and intensely chloritized (Fe-rich chlorite) rocks has been identified. Furthermore, mass changes in more peripheral parts of the altered zone toward the southeast of the deposit suggest that the alteration weakens gradationally toward the volcanic and subvolcanic rocks surrounding the deposit. These patterns represent vectors toward mineralization. Intensely chloritized rocks, largely represented by a ... |
format |
Article in Journal/Newspaper |
author |
Kampmann, Tobias Christoph Jansson, Nils Stephens, Michael Majka, Jarosław Lasskogen, Jonas |
author_facet |
Kampmann, Tobias Christoph Jansson, Nils Stephens, Michael Majka, Jarosław Lasskogen, Jonas |
author_sort |
Kampmann, Tobias Christoph |
title |
Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
title_short |
Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
title_full |
Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
title_fullStr |
Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
title_full_unstemmed |
Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden |
title_sort |
systematics of hydrothermal alteration at the falun base metal sulfide deposit and implications for ore genesis and exploration, bergslagen ore district, fennoscandian shield, sweden |
publisher |
Luleå tekniska universitet, Geovetenskap och miljöteknik |
publishDate |
2017 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-5137 https://doi.org/10.5382/econgeo.2017.4504 |
genre |
Fennoscandian |
genre_facet |
Fennoscandian |
op_relation |
Economic geology and the bulletin of the Society of Economic Geologists, 0361-0128, 2017, 112:5, s. 1111-1152 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-5137 doi:10.5382/econgeo.2017.4504 ISI:000426874300005 Scopus 2-s2.0-85021135933 Local 329616f3-a1ac-49e9-8cfe-bee49ce58aa3 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5382/econgeo.2017.4504 |
container_title |
Economic Geology |
container_volume |
112 |
container_issue |
5 |
container_start_page |
1111 |
op_container_end_page |
1152 |
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1765998708083654656 |