Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis
Cumulus olivine, clinopyroxene, melilite and perovskite from silicate rocks and carbonatites of the Gardiner (East Greenland) and Kovdor (Kola Peninsula) ultramafic alkaline complexes contain primary melt inclusions crystallized into aggregates of daughter minerals. The petrography and homogenizatio...
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fthighwire:oai:open-archive.highwire.org:petrology:39/11-12/2015 2023-05-15T16:03:48+02:00 Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis Veksler, I. V. Nielsen, T. F. D. Sokolov, S. V. 1998-11-01 00:00:00.0 text/html http://petrology.oxfordjournals.org/cgi/content/short/39/11-12/2015 https://doi.org/10.1093/petroj/39.11-12.2015 en eng Oxford University Press http://petrology.oxfordjournals.org/cgi/content/short/39/11-12/2015 http://dx.doi.org/10.1093/petroj/39.11-12.2015 Copyright (C) 1998, Oxford University Press Articles TEXT 1998 fthighwire https://doi.org/10.1093/petroj/39.11-12.2015 2018-04-07T06:23:24Z Cumulus olivine, clinopyroxene, melilite and perovskite from silicate rocks and carbonatites of the Gardiner (East Greenland) and Kovdor (Kola Peninsula) ultramafic alkaline complexes contain primary melt inclusions crystallized into aggregates of daughter minerals. The petrography and homogenization temperatures of the inclusions constrain the fractionation paths and the formation of carbonatites in the complexes. Carbonated melanephelinite was parental to both complexes and early cumulates (dunite, olivinite, peridotite and melteigite) are comparable. The common occurrence of phlogopite and amphibole in the inclusions and in the host rocks indicates that these were important liquidus phases. In both complexes the fractionation of phlogopite and amphibole drove the melts towards Ca-rich (larnite-normative) compositions. At the ijolite stage the evolutionary trends are believed to separate and the evolved larnite-normative melt produced calcite-bearing ijolite in Kovdor and melilitolite in Gardiner. The two assemblages are related by decarbonation reactions. A fractional crystallization origin is suggested for the Kovdor carbonatite, whereas the Gardiner carbonatite formed by liquid immiscibility in the course of melilite fractionation. Na–K–Ca and Na–Mg carbonates are common daughter phases and especially abundant in late-stage inclusions. Thus, all carbonatite melts in the two complexes are alkaline. Calcite carbonatites appear to be cumulates. Text East Greenland Greenland kola peninsula HighWire Press (Stanford University) Gardiner ENVELOPE(-81.583,-81.583,50.683,50.683) Greenland Kola Peninsula Kovdor ENVELOPE(30.620,30.620,67.534,67.534) Journal of Petrology 39 11-12 2015 2031 |
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HighWire Press (Stanford University) |
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fthighwire |
language |
English |
topic |
Articles |
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Articles Veksler, I. V. Nielsen, T. F. D. Sokolov, S. V. Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
topic_facet |
Articles |
description |
Cumulus olivine, clinopyroxene, melilite and perovskite from silicate rocks and carbonatites of the Gardiner (East Greenland) and Kovdor (Kola Peninsula) ultramafic alkaline complexes contain primary melt inclusions crystallized into aggregates of daughter minerals. The petrography and homogenization temperatures of the inclusions constrain the fractionation paths and the formation of carbonatites in the complexes. Carbonated melanephelinite was parental to both complexes and early cumulates (dunite, olivinite, peridotite and melteigite) are comparable. The common occurrence of phlogopite and amphibole in the inclusions and in the host rocks indicates that these were important liquidus phases. In both complexes the fractionation of phlogopite and amphibole drove the melts towards Ca-rich (larnite-normative) compositions. At the ijolite stage the evolutionary trends are believed to separate and the evolved larnite-normative melt produced calcite-bearing ijolite in Kovdor and melilitolite in Gardiner. The two assemblages are related by decarbonation reactions. A fractional crystallization origin is suggested for the Kovdor carbonatite, whereas the Gardiner carbonatite formed by liquid immiscibility in the course of melilite fractionation. Na–K–Ca and Na–Mg carbonates are common daughter phases and especially abundant in late-stage inclusions. Thus, all carbonatite melts in the two complexes are alkaline. Calcite carbonatites appear to be cumulates. |
format |
Text |
author |
Veksler, I. V. Nielsen, T. F. D. Sokolov, S. V. |
author_facet |
Veksler, I. V. Nielsen, T. F. D. Sokolov, S. V. |
author_sort |
Veksler, I. V. |
title |
Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
title_short |
Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
title_full |
Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
title_fullStr |
Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
title_full_unstemmed |
Mineralogy of Crystallized Melt Inclusions from Gardiner and Kovdor Ultramafic Alkaline Complexes: Implications for Carbonatite Genesis |
title_sort |
mineralogy of crystallized melt inclusions from gardiner and kovdor ultramafic alkaline complexes: implications for carbonatite genesis |
publisher |
Oxford University Press |
publishDate |
1998 |
url |
http://petrology.oxfordjournals.org/cgi/content/short/39/11-12/2015 https://doi.org/10.1093/petroj/39.11-12.2015 |
long_lat |
ENVELOPE(-81.583,-81.583,50.683,50.683) ENVELOPE(30.620,30.620,67.534,67.534) |
geographic |
Gardiner Greenland Kola Peninsula Kovdor |
geographic_facet |
Gardiner Greenland Kola Peninsula Kovdor |
genre |
East Greenland Greenland kola peninsula |
genre_facet |
East Greenland Greenland kola peninsula |
op_relation |
http://petrology.oxfordjournals.org/cgi/content/short/39/11-12/2015 http://dx.doi.org/10.1093/petroj/39.11-12.2015 |
op_rights |
Copyright (C) 1998, Oxford University Press |
op_doi |
https://doi.org/10.1093/petroj/39.11-12.2015 |
container_title |
Journal of Petrology |
container_volume |
39 |
container_issue |
11-12 |
container_start_page |
2015 |
op_container_end_page |
2031 |
_version_ |
1766399493036572672 |