Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension
Mafic dykes (Groups A–D) intruded into Mesoproterozoic basement amphibolites, gneisses, and granitoids of the Cape Meredith Complex on the southern tip of West Falkland, provide an important record of at least three periods of lithospheric extension during Palaeozoic and Jurassic times. Group A dyke...
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crcambridgeupr:10.1017/s0016756897007085 2024-03-03T08:37:59+00:00 Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension THISTLEWOOD, L. LEAT, P. T. MILLAR, I. L. STOREY, B. C. VAUGHAN, A. P. M. 1997 http://dx.doi.org/10.1017/s0016756897007085 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007085 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 134, issue 3, page 355-367 ISSN 0016-7568 1469-5081 Geology journal-article 1997 crcambridgeupr https://doi.org/10.1017/s0016756897007085 2024-02-08T08:36:09Z Mafic dykes (Groups A–D) intruded into Mesoproterozoic basement amphibolites, gneisses, and granitoids of the Cape Meredith Complex on the southern tip of West Falkland, provide an important record of at least three periods of lithospheric extension during Palaeozoic and Jurassic times. Group A dykes are calc-alkaline lamprophyres that were generated by partial melting of an enriched subcontinental lithospheric mantle in Cambro-Ordovician times. Group B dykes are Ordovician dolerites derived from an asthenospheric mantle source, perhaps during the same extensional episode as Group A dykes. Group C dykes were also derived from an asthenospheric source and are possibly of Silurian age. The youngest, Group D, dykes are part of the widespread Jurassic Gondwana province. This group contains an oceanic island basalt-like sample and an enriched sample similar to both Group A lamprophyres and to the Jurassic Ferrar province in Antarctica. These correlations have interesting implications for the composition and evolution of mantle sources through time; the co-existence of Cambrian lamprophyres and Jurassic Ferrar-type magmas in the Cape Meredith Complex demonstrate for the first time that the enriched lithospheric mantle source postulated for the Ferrar magmas existed as far back as Cambrian times. Article in Journal/Newspaper Antarc* Antarctica Cambridge University Press Meredith ENVELOPE(67.717,67.717,-71.200,-71.200) Geological Magazine 134 3 355 367 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Geology |
spellingShingle |
Geology THISTLEWOOD, L. LEAT, P. T. MILLAR, I. L. STOREY, B. C. VAUGHAN, A. P. M. Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
topic_facet |
Geology |
description |
Mafic dykes (Groups A–D) intruded into Mesoproterozoic basement amphibolites, gneisses, and granitoids of the Cape Meredith Complex on the southern tip of West Falkland, provide an important record of at least three periods of lithospheric extension during Palaeozoic and Jurassic times. Group A dykes are calc-alkaline lamprophyres that were generated by partial melting of an enriched subcontinental lithospheric mantle in Cambro-Ordovician times. Group B dykes are Ordovician dolerites derived from an asthenospheric mantle source, perhaps during the same extensional episode as Group A dykes. Group C dykes were also derived from an asthenospheric source and are possibly of Silurian age. The youngest, Group D, dykes are part of the widespread Jurassic Gondwana province. This group contains an oceanic island basalt-like sample and an enriched sample similar to both Group A lamprophyres and to the Jurassic Ferrar province in Antarctica. These correlations have interesting implications for the composition and evolution of mantle sources through time; the co-existence of Cambrian lamprophyres and Jurassic Ferrar-type magmas in the Cape Meredith Complex demonstrate for the first time that the enriched lithospheric mantle source postulated for the Ferrar magmas existed as far back as Cambrian times. |
format |
Article in Journal/Newspaper |
author |
THISTLEWOOD, L. LEAT, P. T. MILLAR, I. L. STOREY, B. C. VAUGHAN, A. P. M. |
author_facet |
THISTLEWOOD, L. LEAT, P. T. MILLAR, I. L. STOREY, B. C. VAUGHAN, A. P. M. |
author_sort |
THISTLEWOOD, L. |
title |
Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
title_short |
Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
title_full |
Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
title_fullStr |
Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
title_full_unstemmed |
Basement geology and Palaeozoic–Mesozoic mafic dykes from the Cape Meredith Complex, Falkland Islands: a record of repeated intracontinental extension |
title_sort |
basement geology and palaeozoic–mesozoic mafic dykes from the cape meredith complex, falkland islands: a record of repeated intracontinental extension |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s0016756897007085 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007085 |
long_lat |
ENVELOPE(67.717,67.717,-71.200,-71.200) |
geographic |
Meredith |
geographic_facet |
Meredith |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Geological Magazine volume 134, issue 3, page 355-367 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756897007085 |
container_title |
Geological Magazine |
container_volume |
134 |
container_issue |
3 |
container_start_page |
355 |
op_container_end_page |
367 |
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1792503323735097344 |