Results 71 to 80 of about 127 (117)
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Alkaline‐ultramafic lamprophyres and kimberlites of the Kola Peninsula
Polar Geography and Geology, 1994Abstract The distribution of the alkaline lamprophyres (dikes and diatremes) of the central and southern parts of the Kola Peninsula and of the kimberlite pipes on its southeastern coast is controlled by the Onega‐Kandalaksha graben zone. In the western part of this zone the dikes and diatremes are confined to alkaline‐ultramafic plutons, but in the ...
S. K. Simakov +2 more
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Geochronology of the Qeqertaa Diamondiferous Ultramafic Lamprophyre, West Greenland
International Kimberlite Conference Extended Abstracts: 2024Mark T Hutchison
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Late Cretaceous ultramafic lamprophyres and carbonatites from the Delitzsch Complex, Germany
Chemical Geology, 2013The Delitzsch Complex consists of late Cretaceous ultramafic lamprophyres and carbonatitic rocks. They form dikes and diatremes, emplaced into Palaeozoic to lower Permian volcanic and sedimentary rocks, and are covered by up to 120 m thick sequences of Tertiary sedimentary rocks. The complex includes a diversity of magmatic and subvolcanic rocks.
Krüger, J., Romer, R., Kämpf, H.
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Alkaline mafic and ultramafic lamprophyres from the Aillik Bay area, Labrador
Canadian Journal of Earth Sciences, 1986The Aillik Bay lamprophyric dyke swarm comprises abundant sannaites, plus rarer olivine sannaites, aillikites and carbonatites. Sannaites are characterized by phenocrysts of Ti–Al titansalite plus rarer olivine and phiogopite in a groundmass dominated by pyroxene, biotite, titanomagnetite, and K-feldspar.
Foley, SF, King, AF, Malpas, J
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Torngat ultramafic lamprophyres and their relation to the North Atlantic Alkaline Province
Lithos, 2004Geological mapping and diamond exploration in northern Quebec and Labrador has revealed an undeformed ultramafic dyke swarm in the northern Torngat Mountains. The dyke rocks are dominated by an olivine-phlogopite mineralogy and contain varying amounts of primary carbonate.
Sebastian Tappe +6 more
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Ultramafic Lamprophyres of the Ferrar Large Igneous Province: Evidence for a HIMU Mantle Component
Lithos, 2003Abstract Ultramafic lamprophyre (UML) dykes from the Ferrar Province (Pensacola Mountains) of Antarctica preserve trace element and isotope signatures similar to Bouvet volcanic rocks, which are considered to reflect the palaeo composition of the Bouvet mantle plume.
Ian Parkinson, Teal R Riley, Philip Leat
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Geochemistry of ultramafic and calc-llkaline lamprophyres from the Lac Shortt area, Quebec
Mineralogy and Petrology, 1991Petrographic and geochemical data are presented for the Lac Shortt lamprophyre dyke swarm. The primary mineralogy in all samples has been largely destroyed either by alteration at the time of emplacement or by subsequent metamorphism. Most of the dykes are ultramafic lamprophyres.
J. H. Bourne, J. Boss�
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Mineralogical Magazine, 2000
AbstractAn ultramafic lamprophyre dyke is described from the otherwise tholeiitic Ferrar magmatic province of Antarctica. We report an Ar-Ar age of 183 ± 2.2 Ma for the dyke, indistinguishable from those of the Ferrar tholeiites. However, the dyke has mineralogical and major and trace element compositions, and radiogenic isotopes ratios, very different
Simon P. Kelley, Teal R Riley
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AbstractAn ultramafic lamprophyre dyke is described from the otherwise tholeiitic Ferrar magmatic province of Antarctica. We report an Ar-Ar age of 183 ± 2.2 Ma for the dyke, indistinguishable from those of the Ferrar tholeiites. However, the dyke has mineralogical and major and trace element compositions, and radiogenic isotopes ratios, very different
Simon P. Kelley, Teal R Riley
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Mineralogy and Petrology, 1993
Dykes of alkaline and ultramafic carbonate lamprophyres (monchiquite-ouachitite and aillikite) intrude the Carboniferous sediments of Central Bohemia. Their characteristic feature is the presence of substantial amounts of a sodalite group mineral (presumably hauyne), carbonate and barite. Isotopic compositions ofδ13C (−3.4 to −6.2‰) andδ18O ( + 13.5 to
J. Ulrych +4 more
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Dykes of alkaline and ultramafic carbonate lamprophyres (monchiquite-ouachitite and aillikite) intrude the Carboniferous sediments of Central Bohemia. Their characteristic feature is the presence of substantial amounts of a sodalite group mineral (presumably hauyne), carbonate and barite. Isotopic compositions ofδ13C (−3.4 to −6.2‰) andδ18O ( + 13.5 to
J. Ulrych +4 more
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Petrology of the Ultramafic Lamprophyre and Associated Rocks at Coral Rapids, Abitibi River, Ontario
Canadian Journal of Earth Sciences, 1994An ultramafic lamprophyre sill and dikes, and an olivine–melilite-rich dike rock intrude Lower to Middle Devonian sediments and low- to high-grade Archean metamorphic rocks on the west bank of the Abitibi River, Coral Rapids, Ontario. Although previously considered to be kimberlitic, all these rocks contain olivine + clinopyroxene + phlogopite ...
A. D. Edgar +2 more
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