Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics
Cornwallis Lead-Zinc District in the central Canadian Arctic includes occurrences of galena and sphalerite with similar geological settings and controls on mineralization. It includes the Polaris deposit, with 25 million tons of about 19% grade ore, representing 4.7 million tons of metal.The distric...
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crcansciencepubl:10.1139/e77-124 2024-04-07T07:50:44+00:00 Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics Kerr, J. Wm. 1977 http://dx.doi.org/10.1139/e77-124 http://www.nrcresearchpress.com/doi/pdf/10.1139/e77-124 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 14, issue 6, page 1402-1426 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1977 crcansciencepubl https://doi.org/10.1139/e77-124 2024-03-08T00:37:37Z Cornwallis Lead-Zinc District in the central Canadian Arctic includes occurrences of galena and sphalerite with similar geological settings and controls on mineralization. It includes the Polaris deposit, with 25 million tons of about 19% grade ore, representing 4.7 million tons of metal.The district occurs in and was controlled by the Cornwallis Fold Belt, a steep-sided anticlinorium of Proterozoic to Devonian formations, that overlies a basement horst.Four controls on mineralization are: (A) deposits are stratabound within the Ordovician Thumb Mountain Formation; (B) ore occurs in breciated dolomite, in contrast to usual limestone of the host formation; (C) deposits are located close to shale of the Cape Phillips Formation; and (D) the host formation was subject to erosion and karstification in Early Devonian time during Pulse 3 of the Cornwallis Disturbance.Mineralization is of Mississippi Valley-type, having formed in carbonate rock by epigenetic processes. The sequence of stratigraphic and tectonic events leading to mineral formation was as follows:(1) An Ordovician to Lower Devonian geosynclinal sequence was deposited, containing formations that could be a source of Zn, Pb, Fe, and S, as well as a potential host formation.(2) The sequence was folded by three pulses of the Cornwallis Disturbance.(3) Uplift in Early Devonian time allowed deep erosion that exposed the host Thumb Mountain Formation in anticlinal culminations.(4) Caverns and pores developed in the upper part of that formation, by karst-type solution.(5) During subsidence an unconformable sedimentary cover buried the host formation and its caverns to a considerable depth.(6) Two formation fluids developed, with metal ions in one and sulphur ions in the other.(7) These two brines migrated laterally and upward, and met in cavities in the Thumb Mountain Formation.(8) In these cavities temperatures and other conditions were suitable and the brines precipitated the sulphides, galena, sphalerite, and pyrite.Deposition probably occurred between ... Article in Journal/Newspaper Arctic Canadian Science Publishing Arctic Thumb ENVELOPE(-64.259,-64.259,-65.247,-65.247) Cornwallis ENVELOPE(-54.464,-54.464,-61.072,-61.072) Cape Phillips ENVELOPE(-62.600,-62.600,-84.750,-84.750) The Thumb ENVELOPE(-126.747,-126.747,56.163,56.163) Thumb Mountain ENVELOPE(-81.465,-81.465,79.035,79.035) Canadian Journal of Earth Sciences 14 6 1402 1426 |
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Open Polar |
collection |
Canadian Science Publishing |
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crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Kerr, J. Wm. Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
topic_facet |
General Earth and Planetary Sciences |
description |
Cornwallis Lead-Zinc District in the central Canadian Arctic includes occurrences of galena and sphalerite with similar geological settings and controls on mineralization. It includes the Polaris deposit, with 25 million tons of about 19% grade ore, representing 4.7 million tons of metal.The district occurs in and was controlled by the Cornwallis Fold Belt, a steep-sided anticlinorium of Proterozoic to Devonian formations, that overlies a basement horst.Four controls on mineralization are: (A) deposits are stratabound within the Ordovician Thumb Mountain Formation; (B) ore occurs in breciated dolomite, in contrast to usual limestone of the host formation; (C) deposits are located close to shale of the Cape Phillips Formation; and (D) the host formation was subject to erosion and karstification in Early Devonian time during Pulse 3 of the Cornwallis Disturbance.Mineralization is of Mississippi Valley-type, having formed in carbonate rock by epigenetic processes. The sequence of stratigraphic and tectonic events leading to mineral formation was as follows:(1) An Ordovician to Lower Devonian geosynclinal sequence was deposited, containing formations that could be a source of Zn, Pb, Fe, and S, as well as a potential host formation.(2) The sequence was folded by three pulses of the Cornwallis Disturbance.(3) Uplift in Early Devonian time allowed deep erosion that exposed the host Thumb Mountain Formation in anticlinal culminations.(4) Caverns and pores developed in the upper part of that formation, by karst-type solution.(5) During subsidence an unconformable sedimentary cover buried the host formation and its caverns to a considerable depth.(6) Two formation fluids developed, with metal ions in one and sulphur ions in the other.(7) These two brines migrated laterally and upward, and met in cavities in the Thumb Mountain Formation.(8) In these cavities temperatures and other conditions were suitable and the brines precipitated the sulphides, galena, sphalerite, and pyrite.Deposition probably occurred between ... |
format |
Article in Journal/Newspaper |
author |
Kerr, J. Wm. |
author_facet |
Kerr, J. Wm. |
author_sort |
Kerr, J. Wm. |
title |
Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
title_short |
Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
title_full |
Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
title_fullStr |
Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
title_full_unstemmed |
Cornwallis Lead–Zinc District; Mississippi Valley-type deposits controlled by stratigraphy and tectonics |
title_sort |
cornwallis lead–zinc district; mississippi valley-type deposits controlled by stratigraphy and tectonics |
publisher |
Canadian Science Publishing |
publishDate |
1977 |
url |
http://dx.doi.org/10.1139/e77-124 http://www.nrcresearchpress.com/doi/pdf/10.1139/e77-124 |
long_lat |
ENVELOPE(-64.259,-64.259,-65.247,-65.247) ENVELOPE(-54.464,-54.464,-61.072,-61.072) ENVELOPE(-62.600,-62.600,-84.750,-84.750) ENVELOPE(-126.747,-126.747,56.163,56.163) ENVELOPE(-81.465,-81.465,79.035,79.035) |
geographic |
Arctic Thumb Cornwallis Cape Phillips The Thumb Thumb Mountain |
geographic_facet |
Arctic Thumb Cornwallis Cape Phillips The Thumb Thumb Mountain |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Canadian Journal of Earth Sciences volume 14, issue 6, page 1402-1426 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e77-124 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
14 |
container_issue |
6 |
container_start_page |
1402 |
op_container_end_page |
1426 |
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1795665465837617152 |