A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution
Based on recent detailed mapping, a revised stratigraphic column is proposed for the rocks of the Archean Yellowknife Supergroup in the Yellowknife greenstone belt. The mafic volcanic rocks of the Kam Formation, previously thought to represent the oldest supracrustal rocks of the belt, overlap remna...
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Canadian Science Publishing
1986
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crcansciencepubl:10.1139/e86-049 2024-10-06T13:53:23+00:00 A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution Helmstaedt, H. Padgham, W. A. 1986 http://dx.doi.org/10.1139/e86-049 http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-049 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 23, issue 4, page 454-475 ISSN 0008-4077 1480-3313 journal-article 1986 crcansciencepubl https://doi.org/10.1139/e86-049 2024-09-12T04:13:26Z Based on recent detailed mapping, a revised stratigraphic column is proposed for the rocks of the Archean Yellowknife Supergroup in the Yellowknife greenstone belt. The mafic volcanic rocks of the Kam Formation, previously thought to represent the oldest supracrustal rocks of the belt, overlap remnants of an earlier volcanic–sedimentary sequence, here referred to as the Octopus Formation. As its enormous thickness makes it too unwieldy to be described as a single formation, the Kam Formation is raised to group status and subdivided into four formations. It is proposed that the Kam Group should replace the Beaulieu Group in the Yellowknife area. The Chan Formation, at the base of the Kam Group, consists of multiple gabbroic intrusions that were emplaced into a carapace of pillowed flows. The intrusions locally resemble sheeted mafic dyke complexes in Phanerozoic ophiolites, thought to represent evidence for sea-floor spreading. The Crestaurum Formation, which overlies the Chan Formation, is characterized by massive and pillowed flows interlayered with a number of laterally continuous cherts and felsic tuffs. The Townsite Formation consists of rhyodacite breccias interbedded with felsic tuffs and pillowed dacites. The Yellowknife Bay Formation, at the top of the Kam Group and comprising massive and pillowed flows with pillow breccias and numerous interflow sediments, contains all the important gold deposits mined at Yellowknife. The Banting Formation, directly overlying the Kam Group and consisting of mafic to felsic volcanics, is also given group status and subdivided into two formations. Conglomerates and sandstones of the Jackson Lake Formation, formerly thought to separate the Kam and Banting groups, are considered to represent the youngest rocks of the Yellowknife Supergroup near Yellowknife. Gold-bearing shear zones clearly postdate deposition of the Banting Group, making the rocks of this group a potential target for gold exploration. The presence of remnants of a possible spreading center at the base of ... Article in Journal/Newspaper Yellowknife Canadian Science Publishing Yellowknife Yellowknife Bay ENVELOPE(-114.336,-114.336,62.367,62.367) Canadian Journal of Earth Sciences 23 4 454 475 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Based on recent detailed mapping, a revised stratigraphic column is proposed for the rocks of the Archean Yellowknife Supergroup in the Yellowknife greenstone belt. The mafic volcanic rocks of the Kam Formation, previously thought to represent the oldest supracrustal rocks of the belt, overlap remnants of an earlier volcanic–sedimentary sequence, here referred to as the Octopus Formation. As its enormous thickness makes it too unwieldy to be described as a single formation, the Kam Formation is raised to group status and subdivided into four formations. It is proposed that the Kam Group should replace the Beaulieu Group in the Yellowknife area. The Chan Formation, at the base of the Kam Group, consists of multiple gabbroic intrusions that were emplaced into a carapace of pillowed flows. The intrusions locally resemble sheeted mafic dyke complexes in Phanerozoic ophiolites, thought to represent evidence for sea-floor spreading. The Crestaurum Formation, which overlies the Chan Formation, is characterized by massive and pillowed flows interlayered with a number of laterally continuous cherts and felsic tuffs. The Townsite Formation consists of rhyodacite breccias interbedded with felsic tuffs and pillowed dacites. The Yellowknife Bay Formation, at the top of the Kam Group and comprising massive and pillowed flows with pillow breccias and numerous interflow sediments, contains all the important gold deposits mined at Yellowknife. The Banting Formation, directly overlying the Kam Group and consisting of mafic to felsic volcanics, is also given group status and subdivided into two formations. Conglomerates and sandstones of the Jackson Lake Formation, formerly thought to separate the Kam and Banting groups, are considered to represent the youngest rocks of the Yellowknife Supergroup near Yellowknife. Gold-bearing shear zones clearly postdate deposition of the Banting Group, making the rocks of this group a potential target for gold exploration. The presence of remnants of a possible spreading center at the base of ... |
format |
Article in Journal/Newspaper |
author |
Helmstaedt, H. Padgham, W. A. |
spellingShingle |
Helmstaedt, H. Padgham, W. A. A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
author_facet |
Helmstaedt, H. Padgham, W. A. |
author_sort |
Helmstaedt, H. |
title |
A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
title_short |
A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
title_full |
A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
title_fullStr |
A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
title_full_unstemmed |
A new look at the stratigraphy of the Yellowknife Supergroup at Yellowknife, N.W.T. — implications for the age of gold-bearing shear zones and Archean basin evolution |
title_sort |
new look at the stratigraphy of the yellowknife supergroup at yellowknife, n.w.t. — implications for the age of gold-bearing shear zones and archean basin evolution |
publisher |
Canadian Science Publishing |
publishDate |
1986 |
url |
http://dx.doi.org/10.1139/e86-049 http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-049 |
long_lat |
ENVELOPE(-114.336,-114.336,62.367,62.367) |
geographic |
Yellowknife Yellowknife Bay |
geographic_facet |
Yellowknife Yellowknife Bay |
genre |
Yellowknife |
genre_facet |
Yellowknife |
op_source |
Canadian Journal of Earth Sciences volume 23, issue 4, page 454-475 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e86-049 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
23 |
container_issue |
4 |
container_start_page |
454 |
op_container_end_page |
475 |
_version_ |
1812182087354023936 |