Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments
The sources of rare diamonds reported in northwestern British Columbia, southwestern Yukon, and parts of Alaska are enigmatic. We carried out a heavy-mineral survey of 17 streams draining bedrock in the AtlinNakina region in northwestern British Columbia to determine if high-pressure igneous and me...
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crcansciencepubl:10.1139/e05-069 2024-09-15T18:41:29+00:00 Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments Canil, D Mihalynuk, M MacKenzie, J M Johnston, S T Grant, B 2005 http://dx.doi.org/10.1139/e05-069 http://www.nrcresearchpress.com/doi/pdf/10.1139/e05-069 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 42, issue 12, page 2161-2171 ISSN 0008-4077 1480-3313 journal-article 2005 crcansciencepubl https://doi.org/10.1139/e05-069 2024-07-25T04:10:03Z The sources of rare diamonds reported in northwestern British Columbia, southwestern Yukon, and parts of Alaska are enigmatic. We carried out a heavy-mineral survey of 17 streams draining bedrock in the AtlinNakina region in northwestern British Columbia to determine if high-pressure igneous and metamorphic rocks exhumed in the area could be potential sources for the diamond. Heavy-mineral fractions returned flakes of gold but no diamond. The ferromagnetic fractions were examined optically and by electron microprobe analysis of key indicator minerals, namely olivine, orthopyroxene, clinopyroxene, garnet, spinel, and titanite. Detritus from a horizon of coarse pebble conglomerate in the Jurassic Laberge Group south of Atlin is the most likely source of the anomalous diamond. Garnets and pyroxenes in the latter sedimentary unit were derived by rapid erosion of peridotite and eclogite massif bodies exhumed from depths approaching the diamond stability field during collision and Pliensbachian uplift in the northern Cordillera. Evidence is shown for glacial transport of detritus from both the Laberge Group sediments and Neogene volcanics, the latter of which evidently covered a much wider area before the last glaciation. Article in Journal/Newspaper Alaska Yukon Canadian Science Publishing Canadian Journal of Earth Sciences 42 12 2161 2171 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
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The sources of rare diamonds reported in northwestern British Columbia, southwestern Yukon, and parts of Alaska are enigmatic. We carried out a heavy-mineral survey of 17 streams draining bedrock in the AtlinNakina region in northwestern British Columbia to determine if high-pressure igneous and metamorphic rocks exhumed in the area could be potential sources for the diamond. Heavy-mineral fractions returned flakes of gold but no diamond. The ferromagnetic fractions were examined optically and by electron microprobe analysis of key indicator minerals, namely olivine, orthopyroxene, clinopyroxene, garnet, spinel, and titanite. Detritus from a horizon of coarse pebble conglomerate in the Jurassic Laberge Group south of Atlin is the most likely source of the anomalous diamond. Garnets and pyroxenes in the latter sedimentary unit were derived by rapid erosion of peridotite and eclogite massif bodies exhumed from depths approaching the diamond stability field during collision and Pliensbachian uplift in the northern Cordillera. Evidence is shown for glacial transport of detritus from both the Laberge Group sediments and Neogene volcanics, the latter of which evidently covered a much wider area before the last glaciation. |
format |
Article in Journal/Newspaper |
author |
Canil, D Mihalynuk, M MacKenzie, J M Johnston, S T Grant, B |
spellingShingle |
Canil, D Mihalynuk, M MacKenzie, J M Johnston, S T Grant, B Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
author_facet |
Canil, D Mihalynuk, M MacKenzie, J M Johnston, S T Grant, B |
author_sort |
Canil, D |
title |
Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
title_short |
Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
title_full |
Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
title_fullStr |
Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
title_full_unstemmed |
Diamond in the AtlinNakina region, British Columbia: insights from heavy minerals in stream sediments |
title_sort |
diamond in the atlinnakina region, british columbia: insights from heavy minerals in stream sediments |
publisher |
Canadian Science Publishing |
publishDate |
2005 |
url |
http://dx.doi.org/10.1139/e05-069 http://www.nrcresearchpress.com/doi/pdf/10.1139/e05-069 |
genre |
Alaska Yukon |
genre_facet |
Alaska Yukon |
op_source |
Canadian Journal of Earth Sciences volume 42, issue 12, page 2161-2171 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e05-069 |
container_title |
Canadian Journal of Earth Sciences |
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42 |
container_issue |
12 |
container_start_page |
2161 |
op_container_end_page |
2171 |
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1810485884639772672 |