Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides
The early major products of Tertiary volcanicity in both Skye and Mull are transitional basic lavas, similar in their major-element chemistry to world-wide alkali basalt series. In contrast, their contents of incompatible trace elements bear more resemblance to those of olivine tholeiites. The Mull...
Published in: | Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences |
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crroyalsociety:10.1098/rsta.1980.0212 2024-09-09T19:57:14+00:00 Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides 1980 http://dx.doi.org/10.1098/rsta.1980.0212 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1980.0212 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences volume 297, issue 1431, page 229-244 ISSN 0080-4614 2054-0272 journal-article 1980 crroyalsociety https://doi.org/10.1098/rsta.1980.0212 2024-07-29T04:23:19Z The early major products of Tertiary volcanicity in both Skye and Mull are transitional basic lavas, similar in their major-element chemistry to world-wide alkali basalt series. In contrast, their contents of incompatible trace elements bear more resemblance to those of olivine tholeiites. The Mull basalts have similar ranges of silica saturation, Mg/(Mg+Fe), Y and Yb, but lower overall abundance ranges of strongly incompatible elements than the Skye basalts. The variation of incompatible elements in the Mull and Skye lavas is consistent with a model of a mantle source from which a small amount of melt (no more than 1 % ?) had been extracted, with the pre-Tertiary upper-mantle fusion beneath Mull slightly greater than beneath Skye. Chemical and tectonic considerations suggest that this mantle was neither residual from the formation of the Archaean Lewisian complex, nor emplaced as a result of tension associated with the Gainozoic rifting of the North Atlantic. Data on major and trace elements for a mafic alkalic dyke of the Permian swarms that pass through western Scotland show that these have the requisite geochemical characteristics to have caused this depletion. Such dykes are more abundant in the region of Mull than Skye. Article in Journal/Newspaper North Atlantic The Royal Society Mull ENVELOPE(-63.058,-63.058,-74.536,-74.536) Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences 297 1431 229 244 |
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Open Polar |
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The Royal Society |
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crroyalsociety |
language |
English |
description |
The early major products of Tertiary volcanicity in both Skye and Mull are transitional basic lavas, similar in their major-element chemistry to world-wide alkali basalt series. In contrast, their contents of incompatible trace elements bear more resemblance to those of olivine tholeiites. The Mull basalts have similar ranges of silica saturation, Mg/(Mg+Fe), Y and Yb, but lower overall abundance ranges of strongly incompatible elements than the Skye basalts. The variation of incompatible elements in the Mull and Skye lavas is consistent with a model of a mantle source from which a small amount of melt (no more than 1 % ?) had been extracted, with the pre-Tertiary upper-mantle fusion beneath Mull slightly greater than beneath Skye. Chemical and tectonic considerations suggest that this mantle was neither residual from the formation of the Archaean Lewisian complex, nor emplaced as a result of tension associated with the Gainozoic rifting of the North Atlantic. Data on major and trace elements for a mafic alkalic dyke of the Permian swarms that pass through western Scotland show that these have the requisite geochemical characteristics to have caused this depletion. Such dykes are more abundant in the region of Mull than Skye. |
format |
Article in Journal/Newspaper |
title |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
spellingShingle |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
title_short |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
title_full |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
title_fullStr |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
title_full_unstemmed |
Lateral chemical heterogeneity in the Palaeocene upper mantle beneath the Scottish Hebrides |
title_sort |
lateral chemical heterogeneity in the palaeocene upper mantle beneath the scottish hebrides |
publisher |
The Royal Society |
publishDate |
1980 |
url |
http://dx.doi.org/10.1098/rsta.1980.0212 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1980.0212 |
long_lat |
ENVELOPE(-63.058,-63.058,-74.536,-74.536) |
geographic |
Mull |
geographic_facet |
Mull |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences volume 297, issue 1431, page 229-244 ISSN 0080-4614 2054-0272 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rsta.1980.0212 |
container_title |
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences |
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297 |
container_issue |
1431 |
container_start_page |
229 |
op_container_end_page |
244 |
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1809928140529598464 |