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| Titel |
Tholeiitic ‘komatiite'-basalt and calc-alkaline andesite-dacite succession in the Archaean Kvanefjord Area (South-West Greenland): A composite oceanic and volcanic arc suite? |
| VerfasserIn |
Martin B. Klausen, Thomas F. Kokfelt, Nynke Keulen, Alfons Berger, John C. Schumacher |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250055056
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| Zusammenfassung |
| The Archaean Craton in South-West Greenland is made up of a series of predominantly
amphibolite facies crustal terranes, which in the Kvanefjord area (~62°S) are dominated by
foliated TTG gneisses and a number of inter-folded amphibolite belts. These ca. 4 km wide
and synfomally folded belts appear as dismembered parts of a presumed continuous
supracrustal sequence. One supracrustal belt on the Nigerlikasik peninsula was visited during
the 2010 GEUS-led (co-sponsored by Greenland Bureau of Mining and Petroleum) field
expedition in the area, with the intent of establishing a detailed stratigraphical log and a dense
sampling profile for geochemical and geochronological characterisation. The sequence at
Nigerlikasik is relatively well-preserved and undeformed, and describes a compositional
evolution from ultramafic serpentinites near the base (~30 m), to mafic amphibolites
through mid-section (~230 m), to felsic schists in the top-section (~300 m). All
rocks are of likely igneous origins based on examples of relict volcanic structures,
such as possible fiamme-textured ignimbrites, pyroclastic breccia-flows and rare
pillow-basalts. The sequence was intruded by some syn-volcanic gabbroic intrusions in
the mafic lower part of the section. The latest magmatic activity is represented by
vaguely oblique, cross-cutting aplite sheets ( |
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