Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion
The Sixtymile gold district, Yukon, Canada has been mined for placer gold since the late 19th century. However, increasing demand for gold has prompted exploration of new lode deposits. Previous studies in the nearby Klondike gold district have shown correlation between placer deposits and bedrock o...
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ftmdpi:oai:mdpi.com:/2075-163X/12/3/291/ 2023-08-20T04:06:44+02:00 Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion Jeremy Rimando Alexander L. Peace Meixia Geng Jacob Verbaas Harley Slade agris 2022-02-25 application/pdf https://doi.org/10.3390/min12030291 EN eng Multidisciplinary Digital Publishing Institute Mineral Exploration Methods and Applications https://dx.doi.org/10.3390/min12030291 https://creativecommons.org/licenses/by/4.0/ Minerals; Volume 12; Issue 3; Pages: 291 Sixtymile gold district structural controls 3D magnetic susceptibility Text 2022 ftmdpi https://doi.org/10.3390/min12030291 2023-08-01T04:17:31Z The Sixtymile gold district, Yukon, Canada has been mined for placer gold since the late 19th century. However, increasing demand for gold has prompted exploration of new lode deposits. Previous studies in the nearby Klondike gold district have shown correlation between placer deposits and bedrock occurrences. Poor bedrock exposure and a complex deformation history, however, make it difficult to determine structural controls on gold mineralization. Through structural analysis involving mesoscopic-scale field observations of fractures, faults, foliation, and folds, and 3D geophysical inversion, the goal of this study was to determine the structural setting of the Sixtymile district to enhance discovery success. Structural measurements in the Glacier Creek, Miller Creek, Bedrock Creek, and Sixtymile River areas show the relationships among the orientations of foliation, fractures, and veins. In most localities, veins are found both parallel and at high angles to foliation, and there is generally a weaker correlation between fractures and veins compared to between foliation and veins. This correlation between foliation and veins is corroborated by inferred gold-bearing horizons from gold assay data. Outcrops of oblique reverse and strike-slip faults, possibly related to a larger-scale thrust-zone, and to the left-lateral Sixtymile-Pika Fault, respectively, were documented for the first time in this study. The results of the 3D probabilistic inversion of total magnetic intensity data for magnetic susceptibility show that magnetic susceptibility highs are preferentially associated with volcanics, but also point to possible intrusive bodies or hydrothermal alteration zones associated with mineralization. A geologic cross-section through the lithologies demonstrates highly variable deformation styles, including extensive folding, possibly indicative of a multiphase deformational history necessitating further, more detailed investigations of the area. Text glacier* Yukon MDPI Open Access Publishing Yukon Canada Glacier Creek ENVELOPE(-128.737,-128.737,54.666,54.666) Sixtymile ENVELOPE(-140.750,-140.750,64.027,64.027) Bedrock Creek ENVELOPE(-140.867,-140.867,63.967,63.967) Minerals 12 3 291 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
Sixtymile gold district structural controls 3D magnetic susceptibility |
spellingShingle |
Sixtymile gold district structural controls 3D magnetic susceptibility Jeremy Rimando Alexander L. Peace Meixia Geng Jacob Verbaas Harley Slade Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
topic_facet |
Sixtymile gold district structural controls 3D magnetic susceptibility |
description |
The Sixtymile gold district, Yukon, Canada has been mined for placer gold since the late 19th century. However, increasing demand for gold has prompted exploration of new lode deposits. Previous studies in the nearby Klondike gold district have shown correlation between placer deposits and bedrock occurrences. Poor bedrock exposure and a complex deformation history, however, make it difficult to determine structural controls on gold mineralization. Through structural analysis involving mesoscopic-scale field observations of fractures, faults, foliation, and folds, and 3D geophysical inversion, the goal of this study was to determine the structural setting of the Sixtymile district to enhance discovery success. Structural measurements in the Glacier Creek, Miller Creek, Bedrock Creek, and Sixtymile River areas show the relationships among the orientations of foliation, fractures, and veins. In most localities, veins are found both parallel and at high angles to foliation, and there is generally a weaker correlation between fractures and veins compared to between foliation and veins. This correlation between foliation and veins is corroborated by inferred gold-bearing horizons from gold assay data. Outcrops of oblique reverse and strike-slip faults, possibly related to a larger-scale thrust-zone, and to the left-lateral Sixtymile-Pika Fault, respectively, were documented for the first time in this study. The results of the 3D probabilistic inversion of total magnetic intensity data for magnetic susceptibility show that magnetic susceptibility highs are preferentially associated with volcanics, but also point to possible intrusive bodies or hydrothermal alteration zones associated with mineralization. A geologic cross-section through the lithologies demonstrates highly variable deformation styles, including extensive folding, possibly indicative of a multiphase deformational history necessitating further, more detailed investigations of the area. |
format |
Text |
author |
Jeremy Rimando Alexander L. Peace Meixia Geng Jacob Verbaas Harley Slade |
author_facet |
Jeremy Rimando Alexander L. Peace Meixia Geng Jacob Verbaas Harley Slade |
author_sort |
Jeremy Rimando |
title |
Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
title_short |
Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
title_full |
Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
title_fullStr |
Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
title_full_unstemmed |
Structural Setting of the Sixtymile Gold District, Yukon, Canada: Insights into Regional Deformation and Mineralization from Field Mapping and 3D Magnetic Inversion |
title_sort |
structural setting of the sixtymile gold district, yukon, canada: insights into regional deformation and mineralization from field mapping and 3d magnetic inversion |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/min12030291 |
op_coverage |
agris |
long_lat |
ENVELOPE(-128.737,-128.737,54.666,54.666) ENVELOPE(-140.750,-140.750,64.027,64.027) ENVELOPE(-140.867,-140.867,63.967,63.967) |
geographic |
Yukon Canada Glacier Creek Sixtymile Bedrock Creek |
geographic_facet |
Yukon Canada Glacier Creek Sixtymile Bedrock Creek |
genre |
glacier* Yukon |
genre_facet |
glacier* Yukon |
op_source |
Minerals; Volume 12; Issue 3; Pages: 291 |
op_relation |
Mineral Exploration Methods and Applications https://dx.doi.org/10.3390/min12030291 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/min12030291 |
container_title |
Minerals |
container_volume |
12 |
container_issue |
3 |
container_start_page |
291 |
_version_ |
1774718016085295104 |