Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland.
Tertiary peralkaline acid rocks (comendites) are described from East Greenland. These are dike rocks, which may be aphyric, carry sparse phenocrysts of alkali feldspar, or more abundant quartz, alkali feldspar and katophorite phenocrysts. Regarded as being closely related, are a group of peralkaline...
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Kommissionen for Videnskabelige Undersøgelser i Grønland
1976
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ftsbaarhusojs:oai:ojs.tidsskrift.dk:article/147765 2024-09-15T18:04:14+00:00 Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. Brooks, C. K. Rucklidge, J. C. 1976-01-01 application/pdf https://tidsskrift.dk/meddrgroenland/article/view/147765 eng eng Kommissionen for Videnskabelige Undersøgelser i Grønland https://tidsskrift.dk/meddrgroenland/article/view/147765/190828 https://tidsskrift.dk/meddrgroenland/article/view/147765 Copyright (c) 1976 Copyright for all papers published by Kommisionen for videnskagelige Undersøgelser i Grønland is vested in the Commission. Those who aske for permission to reproduce material from the Commission's publications are, however, informed that the author's permission must also be obtained if he is still alive. Meddelelser om Grønland; Vol. 197 No. 3 (1976): Meddelelser om Grønland; 28 pp. Meddelelser om Grønland; Årg. 197 Nr. 3 (1976): Meddelelser om Grønland; 28 pp. 2794-6827 0025-6676 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Fagfællebedømt artikel 1976 ftsbaarhusojs 2024-07-30T23:38:35Z Tertiary peralkaline acid rocks (comendites) are described from East Greenland. These are dike rocks, which may be aphyric, carry sparse phenocrysts of alkali feldspar, or more abundant quartz, alkali feldspar and katophorite phenocrysts. Regarded as being closely related, are a group of peralkaline granitic rocks associated with the nordmarkitic syenites of the area, which contain quartz, alkali feldspars, arfvedsonite, pyroxenes ranging from hedenbergitic to acmitic, and assessories including zircon, Mn-rich ilmenite, astrophyllite and chevkinite. Analyses are presented for most of these phases and the chemistry of the rocks and that of the crystallization process in the dike centres is discussed. These rocks have an origin clearly distinct from that of the nearby Skaergaard granophyres, which show no peralkaline tendencies, and it is postulated that the comendites have arisen from magmas of nordmarkitic composition which, in turn, arose at depth from a transitional basalt. This suite of rocks seems to reflect closely the tectonic setting, occurring in many areas of crustal attenuation, a situation in accordance with that believed to be present here. Tertiary peralkaline acid rocks (comendites) are described from East Greenland. These are dike rocks, which may be aphyric, carry sparse phenocrysts of alkali feldspar, or more abundant quartz, alkali feldspar and katophorite phenocrysts. Regarded as being closely related, are a group of peralkaline granitic rocks associated with the nordmarkitic syenites of the area, which contain quartz, alkali feldspars, arfvedsonite, pyroxenes ranging from hedenbergitic to acmitic, and assessories including zircon, Mn-rich ilmenite, astrophyllite and chevkinite. Analyses are presented for most of these phases and the chemistry of the rocks and that of the crystallization process in the dike centres is discussed. These rocks have an origin clearly distinct from that of the nearby Skaergaard granophyres, which show no peralkaline tendencies, and it is postulated that the ... Article in Journal/Newspaper East Greenland Greenland Aarhus University: OJS at The State and University Library |
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Aarhus University: OJS at The State and University Library |
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ftsbaarhusojs |
language |
English |
description |
Tertiary peralkaline acid rocks (comendites) are described from East Greenland. These are dike rocks, which may be aphyric, carry sparse phenocrysts of alkali feldspar, or more abundant quartz, alkali feldspar and katophorite phenocrysts. Regarded as being closely related, are a group of peralkaline granitic rocks associated with the nordmarkitic syenites of the area, which contain quartz, alkali feldspars, arfvedsonite, pyroxenes ranging from hedenbergitic to acmitic, and assessories including zircon, Mn-rich ilmenite, astrophyllite and chevkinite. Analyses are presented for most of these phases and the chemistry of the rocks and that of the crystallization process in the dike centres is discussed. These rocks have an origin clearly distinct from that of the nearby Skaergaard granophyres, which show no peralkaline tendencies, and it is postulated that the comendites have arisen from magmas of nordmarkitic composition which, in turn, arose at depth from a transitional basalt. This suite of rocks seems to reflect closely the tectonic setting, occurring in many areas of crustal attenuation, a situation in accordance with that believed to be present here. Tertiary peralkaline acid rocks (comendites) are described from East Greenland. These are dike rocks, which may be aphyric, carry sparse phenocrysts of alkali feldspar, or more abundant quartz, alkali feldspar and katophorite phenocrysts. Regarded as being closely related, are a group of peralkaline granitic rocks associated with the nordmarkitic syenites of the area, which contain quartz, alkali feldspars, arfvedsonite, pyroxenes ranging from hedenbergitic to acmitic, and assessories including zircon, Mn-rich ilmenite, astrophyllite and chevkinite. Analyses are presented for most of these phases and the chemistry of the rocks and that of the crystallization process in the dike centres is discussed. These rocks have an origin clearly distinct from that of the nearby Skaergaard granophyres, which show no peralkaline tendencies, and it is postulated that the ... |
format |
Article in Journal/Newspaper |
author |
Brooks, C. K. Rucklidge, J. C. |
spellingShingle |
Brooks, C. K. Rucklidge, J. C. Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
author_facet |
Brooks, C. K. Rucklidge, J. C. |
author_sort |
Brooks, C. K. |
title |
Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
title_short |
Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
title_full |
Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
title_fullStr |
Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
title_full_unstemmed |
Tertiary peralkaline rhyolite dikes from the Skærgaard area, Kangerdlugssuaq, East Greenland. |
title_sort |
tertiary peralkaline rhyolite dikes from the skærgaard area, kangerdlugssuaq, east greenland. |
publisher |
Kommissionen for Videnskabelige Undersøgelser i Grønland |
publishDate |
1976 |
url |
https://tidsskrift.dk/meddrgroenland/article/view/147765 |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_source |
Meddelelser om Grønland; Vol. 197 No. 3 (1976): Meddelelser om Grønland; 28 pp. Meddelelser om Grønland; Årg. 197 Nr. 3 (1976): Meddelelser om Grønland; 28 pp. 2794-6827 0025-6676 |
op_relation |
https://tidsskrift.dk/meddrgroenland/article/view/147765/190828 https://tidsskrift.dk/meddrgroenland/article/view/147765 |
op_rights |
Copyright (c) 1976 Copyright for all papers published by Kommisionen for videnskagelige Undersøgelser i Grønland is vested in the Commission. Those who aske for permission to reproduce material from the Commission's publications are, however, informed that the author's permission must also be obtained if he is still alive. |
_version_ |
1810441740734169088 |