Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt
Magmas erupted at convergent margins consist of components from both mantle wedge and subducted slab. In an effort to quantify the relative contributions of these sources, we have determined 19 trace element partition coefficients (D values) for orthopyroxene and clinopyroxene, in equilibrium with s...
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/883c9300-353e-44ce-b6ec-77b77d840619 2024-05-19T07:48:43+00:00 Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt McDade, Paula Blundy, Jon D. Wood, Bernard J. 2003-11 https://researchers.mq.edu.au/en/publications/883c9300-353e-44ce-b6ec-77b77d840619 http://www.scopus.com/inward/record.url?scp=0346670104&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess McDade , P , Blundy , J D & Wood , B J 2003 , ' Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt ' , American Mineralogist , vol. 88 , no. 11-12 PART 1 , pp. 1825-1831 . article 2003 ftmacquarieunicr 2024-04-23T02:49:45Z Magmas erupted at convergent margins consist of components from both mantle wedge and subducted slab. In an effort to quantify the relative contributions of these sources, we have determined 19 trace element partition coefficients (D values) for orthopyroxene and clinopyroxene, in equilibrium with spinel and hydrous high-MgO melt under conditions appropriate to melting in the mantle wedge, i.e., 1.3 GPa, 1245 °C, and ∫ o2 of NNO + 1. All trace elements are more incompatible in clinopyroxene during hydrous melting than during anhydrous melting of fertile and depleted peridotite. Orthopyroxene D values are relatively insensitive to pressure, temperature, and phase composition. The new D values are used to calculate the trace-element composition of the mantle wedge, which produced primitive South Sandwich Islands and St. Vincent (Lesser Antilles) arc basalts. Both sources correspond to previously depleted mantle that has been enriched in LILEs and LREEs by slab-derived fluids. In the case of the South Sandwich Islands, the calculated source is in very close agreement with dredged fore-arc lherzolites. Our partitioning data confirm that hydrous melting of wedge peridotite itself cannot produce the characteristic enrichments of LILEs over REEs and HFSEs. Our estimates of the slab component in South Sandwich Islands and St. Vincent are consistent with estimates from other arcs, derived by alternative methods. Article in Journal/Newspaper South Sandwich Islands Macquarie University Research Portal |
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Macquarie University Research Portal |
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English |
description |
Magmas erupted at convergent margins consist of components from both mantle wedge and subducted slab. In an effort to quantify the relative contributions of these sources, we have determined 19 trace element partition coefficients (D values) for orthopyroxene and clinopyroxene, in equilibrium with spinel and hydrous high-MgO melt under conditions appropriate to melting in the mantle wedge, i.e., 1.3 GPa, 1245 °C, and ∫ o2 of NNO + 1. All trace elements are more incompatible in clinopyroxene during hydrous melting than during anhydrous melting of fertile and depleted peridotite. Orthopyroxene D values are relatively insensitive to pressure, temperature, and phase composition. The new D values are used to calculate the trace-element composition of the mantle wedge, which produced primitive South Sandwich Islands and St. Vincent (Lesser Antilles) arc basalts. Both sources correspond to previously depleted mantle that has been enriched in LILEs and LREEs by slab-derived fluids. In the case of the South Sandwich Islands, the calculated source is in very close agreement with dredged fore-arc lherzolites. Our partitioning data confirm that hydrous melting of wedge peridotite itself cannot produce the characteristic enrichments of LILEs over REEs and HFSEs. Our estimates of the slab component in South Sandwich Islands and St. Vincent are consistent with estimates from other arcs, derived by alternative methods. |
format |
Article in Journal/Newspaper |
author |
McDade, Paula Blundy, Jon D. Wood, Bernard J. |
spellingShingle |
McDade, Paula Blundy, Jon D. Wood, Bernard J. Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
author_facet |
McDade, Paula Blundy, Jon D. Wood, Bernard J. |
author_sort |
McDade, Paula |
title |
Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
title_short |
Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
title_full |
Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
title_fullStr |
Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
title_full_unstemmed |
Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt |
title_sort |
trace element partitioning between mantle wedge peridotite and hydrous mgo-rich melt |
publishDate |
2003 |
url |
https://researchers.mq.edu.au/en/publications/883c9300-353e-44ce-b6ec-77b77d840619 http://www.scopus.com/inward/record.url?scp=0346670104&partnerID=8YFLogxK |
genre |
South Sandwich Islands |
genre_facet |
South Sandwich Islands |
op_source |
McDade , P , Blundy , J D & Wood , B J 2003 , ' Trace element partitioning between mantle wedge peridotite and hydrous MgO-rich melt ' , American Mineralogist , vol. 88 , no. 11-12 PART 1 , pp. 1825-1831 . |
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info:eu-repo/semantics/restrictedAccess |
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1799467048050360320 |