Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada
Small-volume, subaerial, subaqueous and subglacial basaltic eruptions occurred in the Wells Gray–Clearwater area during Quaternary time. Part of this time, significant thicknesses of glacial ice were present. Dating of intraglacial volcanic features corroborates other evidence of an Early Pleistocen...
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crcansciencepubl:10.1139/e95-070 2024-09-15T18:12:34+00:00 Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada Hickson, Catherine J. Moore, James G. Calk, Lewis Metcalfe, Paul 1995 http://dx.doi.org/10.1139/e95-070 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-070 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 32, issue 7, page 838-851 ISSN 0008-4077 1480-3313 journal-article 1995 crcansciencepubl https://doi.org/10.1139/e95-070 2024-07-25T04:10:06Z Small-volume, subaerial, subaqueous and subglacial basaltic eruptions occurred in the Wells Gray–Clearwater area during Quaternary time. Part of this time, significant thicknesses of glacial ice were present. Dating of intraglacial volcanic features corroborates other evidence of an Early Pleistocene, Cordilleran-wide ice sheet. Of the intraglacial volcanoes investigated, three were studied in detail and of these, two probably erupted during the Fraser glaciation (11–20 ka), when maximum ice level exceeded 2100 m elevation. Major-element and sulphur concentrations were measured in glass from the volcanoes to provide insight into vent conditions at the time of eruption. Hyalo Ridge (2102 m elevation, whole-rock K–Ar age of 0.02 ± 0.01 Ma) is a small volcanic edifice capped by lava flows with coherent pillowed lavas and interbedded hyaloclastite exposed over nearly 400 m altitude on its east flank. Low sulphur content (<0.03 wt.%) in pillow rim glasses indicates that the lavas are degassed. It is interpreted that the vent built above the water (or ice) surface then fed lava flows that crossed a shoreline and produced pillowed flows. Pyramid Mountain is a volcanic cone 240 m high, comprised of glassy, vesicular, lapilli-tuff breccia. The highly alkalic glass contains 0.1 wt.% S (considered high), and indicates a high original volatile content and drastic quenching, probably during phreatomagmatic eruption from a meltwater-flooded vent. East of the Clearwater River a sequence of massive pillowed flows and pillow joint-block breccias is exposed from 880 to 1320 m elevation (0.27 ± 0.05 Ma). The vent location is unknown. Moderate S content (0.040–0.055 wt.%) indicates that the lavas were erupted in shallow water and are largely degassed. The S content of glass in dykes cutting the pillow breccias is low. The dykes are interpreted as lava that has flowed laterally or down into cracks. Article in Journal/Newspaper Ice Sheet Canadian Science Publishing Canadian Journal of Earth Sciences 32 7 838 851 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Small-volume, subaerial, subaqueous and subglacial basaltic eruptions occurred in the Wells Gray–Clearwater area during Quaternary time. Part of this time, significant thicknesses of glacial ice were present. Dating of intraglacial volcanic features corroborates other evidence of an Early Pleistocene, Cordilleran-wide ice sheet. Of the intraglacial volcanoes investigated, three were studied in detail and of these, two probably erupted during the Fraser glaciation (11–20 ka), when maximum ice level exceeded 2100 m elevation. Major-element and sulphur concentrations were measured in glass from the volcanoes to provide insight into vent conditions at the time of eruption. Hyalo Ridge (2102 m elevation, whole-rock K–Ar age of 0.02 ± 0.01 Ma) is a small volcanic edifice capped by lava flows with coherent pillowed lavas and interbedded hyaloclastite exposed over nearly 400 m altitude on its east flank. Low sulphur content (<0.03 wt.%) in pillow rim glasses indicates that the lavas are degassed. It is interpreted that the vent built above the water (or ice) surface then fed lava flows that crossed a shoreline and produced pillowed flows. Pyramid Mountain is a volcanic cone 240 m high, comprised of glassy, vesicular, lapilli-tuff breccia. The highly alkalic glass contains 0.1 wt.% S (considered high), and indicates a high original volatile content and drastic quenching, probably during phreatomagmatic eruption from a meltwater-flooded vent. East of the Clearwater River a sequence of massive pillowed flows and pillow joint-block breccias is exposed from 880 to 1320 m elevation (0.27 ± 0.05 Ma). The vent location is unknown. Moderate S content (0.040–0.055 wt.%) indicates that the lavas were erupted in shallow water and are largely degassed. The S content of glass in dykes cutting the pillow breccias is low. The dykes are interpreted as lava that has flowed laterally or down into cracks. |
format |
Article in Journal/Newspaper |
author |
Hickson, Catherine J. Moore, James G. Calk, Lewis Metcalfe, Paul |
spellingShingle |
Hickson, Catherine J. Moore, James G. Calk, Lewis Metcalfe, Paul Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
author_facet |
Hickson, Catherine J. Moore, James G. Calk, Lewis Metcalfe, Paul |
author_sort |
Hickson, Catherine J. |
title |
Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
title_short |
Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
title_full |
Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
title_fullStr |
Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
title_full_unstemmed |
Intraglacial volcanism in the Wells Gray–Clearwater volcanic field, east-central British Columbia, Canada |
title_sort |
intraglacial volcanism in the wells gray–clearwater volcanic field, east-central british columbia, canada |
publisher |
Canadian Science Publishing |
publishDate |
1995 |
url |
http://dx.doi.org/10.1139/e95-070 http://www.nrcresearchpress.com/doi/pdf/10.1139/e95-070 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Canadian Journal of Earth Sciences volume 32, issue 7, page 838-851 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e95-070 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
32 |
container_issue |
7 |
container_start_page |
838 |
op_container_end_page |
851 |
_version_ |
1810450159484534784 |