Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India
An early Cretaceous potassic lamprophyre dyke, exposed near Rongjeng, East Garo Hills, Shillong plateau, north-eastern India, is a highly porphyritic rock with large phenocrysts of clinopyroxene, phlogopite, amphibole and olivine. Reversely zoned phlogopite and clinopyroxene grains indicate that som...
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Online Access: | http://hdl.handle.net/11588/652600 https://doi.org/10.18520/cs/v110/i4/649-658 |
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ftunivnapoliiris:oai:www.iris.unina.it:11588/652600 2024-02-04T09:55:31+01:00 Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India Srivastava, Rajesh K. MELLUSO, LEONE Sinha, Anup K. Srivastava, Rajesh K. Melluso, Leone Sinha, Anup K. 2016 http://hdl.handle.net/11588/652600 https://doi.org/10.18520/cs/v110/i4/649-658 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000370491500037 volume:110 issue:4 firstpage:649 lastpage:658 numberofpages:10 journal:CURRENT SCIENCE http://hdl.handle.net/11588/652600 doi:10.18520/cs/v110/i4/649-658 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84959495418 info:eu-repo/semantics/article 2016 ftunivnapoliiris https://doi.org/10.18520/cs/v110/i4/649-658 2024-01-09T23:44:49Z An early Cretaceous potassic lamprophyre dyke, exposed near Rongjeng, East Garo Hills, Shillong plateau, north-eastern India, is a highly porphyritic rock with large phenocrysts of clinopyroxene, phlogopite, amphibole and olivine. Reversely zoned phlogopite and clinopyroxene grains indicate that some degree of interaction between magma batches of variable composition took place somewhere during the crystallization of the lamprophyre. Mineral composi-tions indicate its derivation from an alkaline magma comparable with those that filled the nearby Jasra potassic intrusion. Moreover, the geochemistry of the Rongjeng lamprophyre is distinctly different from that of the Damodar Valley lamproites, the Sung Val-ley carbonatitic-ijolitic intrusion, and the Antarctic ultramafic lamprophyres. The contrasting geochemi-cal affinity is suggestive of heterogenous lithospheric mantle sources, rather than input of plume-related magmatism. Article in Journal/Newspaper Antarc* Antarctic IRIS Università degli Studi di Napoli Federico II Antarctic The Antarctic Current Science 110 4 649 |
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Open Polar |
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IRIS Università degli Studi di Napoli Federico II |
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ftunivnapoliiris |
language |
English |
description |
An early Cretaceous potassic lamprophyre dyke, exposed near Rongjeng, East Garo Hills, Shillong plateau, north-eastern India, is a highly porphyritic rock with large phenocrysts of clinopyroxene, phlogopite, amphibole and olivine. Reversely zoned phlogopite and clinopyroxene grains indicate that some degree of interaction between magma batches of variable composition took place somewhere during the crystallization of the lamprophyre. Mineral composi-tions indicate its derivation from an alkaline magma comparable with those that filled the nearby Jasra potassic intrusion. Moreover, the geochemistry of the Rongjeng lamprophyre is distinctly different from that of the Damodar Valley lamproites, the Sung Val-ley carbonatitic-ijolitic intrusion, and the Antarctic ultramafic lamprophyres. The contrasting geochemi-cal affinity is suggestive of heterogenous lithospheric mantle sources, rather than input of plume-related magmatism. |
author2 |
Srivastava, Rajesh K. Melluso, Leone Sinha, Anup K. |
format |
Article in Journal/Newspaper |
author |
Srivastava, Rajesh K. MELLUSO, LEONE Sinha, Anup K. |
spellingShingle |
Srivastava, Rajesh K. MELLUSO, LEONE Sinha, Anup K. Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
author_facet |
Srivastava, Rajesh K. MELLUSO, LEONE Sinha, Anup K. |
author_sort |
Srivastava, Rajesh K. |
title |
Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
title_short |
Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
title_full |
Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
title_fullStr |
Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
title_full_unstemmed |
Petrogenesis of an early Cretaceous potassic lamprophyre dyke from Rongjeng, East Garo Hills, Shillong plateau, north-eastern India |
title_sort |
petrogenesis of an early cretaceous potassic lamprophyre dyke from rongjeng, east garo hills, shillong plateau, north-eastern india |
publishDate |
2016 |
url |
http://hdl.handle.net/11588/652600 https://doi.org/10.18520/cs/v110/i4/649-658 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000370491500037 volume:110 issue:4 firstpage:649 lastpage:658 numberofpages:10 journal:CURRENT SCIENCE http://hdl.handle.net/11588/652600 doi:10.18520/cs/v110/i4/649-658 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84959495418 |
op_doi |
https://doi.org/10.18520/cs/v110/i4/649-658 |
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Current Science |
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110 |
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4 |
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649 |
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1789959532897632256 |