Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada
Abstract The Abitau Lake area, N.W.T., chiefly consists of medium-to-coarse-grained quartzo-feldspathic gneisses. Many of these are granoblastic, presenting little or no microscopic evidence of deformation. Others are highly tectonized and foliated varieties that sometimes form pseudomigmatites easi...
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Language: | English |
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Cambridge University Press (CUP)
1959
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Online Access: | http://dx.doi.org/10.1017/s0016756800059185 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800059185 |
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crcambridgeupr:10.1017/s0016756800059185 2024-03-03T08:47:32+00:00 Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada Harry, W. T. 1959 http://dx.doi.org/10.1017/s0016756800059185 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800059185 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 96, issue 1, page 25-32 ISSN 0016-7568 1469-5081 Geology journal-article 1959 crcambridgeupr https://doi.org/10.1017/s0016756800059185 2024-02-08T08:24:40Z Abstract The Abitau Lake area, N.W.T., chiefly consists of medium-to-coarse-grained quartzo-feldspathic gneisses. Many of these are granoblastic, presenting little or no microscopic evidence of deformation. Others are highly tectonized and foliated varieties that sometimes form pseudomigmatites easily mistaken in the field for true migmatites formed by lit-par-lit injection of pink granite into more basic grey gneiss. The last, however, are found after detailed examination to be granitic rocks that owe their misleading appearance and distinctive fabric to deformation during isochemical amphibolite fades metamorphism. Surprisingly they are not mylonites. Their fabric, like that of the other foliated gneisses is dominated by the parallelism of dark minerals and elongated quartz crystals. It resembles that of typical European granulites and often seems largely due to compression acting in a direction normal to the foliation plane with little or no transport in that plane. Tectoniza-tion did not promote the formation of myrmekite or microperthite but may have assisted to some extent the production of epidote from hornblende in certain specimens. Article in Journal/Newspaper Northwest Territories Cambridge University Press Northwest Territories Canada Abitau Lake ENVELOPE(-107.251,-107.251,60.450,60.450) Geological Magazine 96 1 25 32 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Geology |
spellingShingle |
Geology Harry, W. T. Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
topic_facet |
Geology |
description |
Abstract The Abitau Lake area, N.W.T., chiefly consists of medium-to-coarse-grained quartzo-feldspathic gneisses. Many of these are granoblastic, presenting little or no microscopic evidence of deformation. Others are highly tectonized and foliated varieties that sometimes form pseudomigmatites easily mistaken in the field for true migmatites formed by lit-par-lit injection of pink granite into more basic grey gneiss. The last, however, are found after detailed examination to be granitic rocks that owe their misleading appearance and distinctive fabric to deformation during isochemical amphibolite fades metamorphism. Surprisingly they are not mylonites. Their fabric, like that of the other foliated gneisses is dominated by the parallelism of dark minerals and elongated quartz crystals. It resembles that of typical European granulites and often seems largely due to compression acting in a direction normal to the foliation plane with little or no transport in that plane. Tectoniza-tion did not promote the formation of myrmekite or microperthite but may have assisted to some extent the production of epidote from hornblende in certain specimens. |
format |
Article in Journal/Newspaper |
author |
Harry, W. T. |
author_facet |
Harry, W. T. |
author_sort |
Harry, W. T. |
title |
Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
title_short |
Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
title_full |
Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
title_fullStr |
Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
title_full_unstemmed |
Pseudomigmatites in the Abitau Lake Area, District of Mackenzie, Northwest Territories, Canada |
title_sort |
pseudomigmatites in the abitau lake area, district of mackenzie, northwest territories, canada |
publisher |
Cambridge University Press (CUP) |
publishDate |
1959 |
url |
http://dx.doi.org/10.1017/s0016756800059185 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800059185 |
long_lat |
ENVELOPE(-107.251,-107.251,60.450,60.450) |
geographic |
Northwest Territories Canada Abitau Lake |
geographic_facet |
Northwest Territories Canada Abitau Lake |
genre |
Northwest Territories |
genre_facet |
Northwest Territories |
op_source |
Geological Magazine volume 96, issue 1, page 25-32 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756800059185 |
container_title |
Geological Magazine |
container_volume |
96 |
container_issue |
1 |
container_start_page |
25 |
op_container_end_page |
32 |
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1792503753586245632 |