Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage
New 40Ar-39Ar ages of 5.6 to 1.3 Ma for lavas from the fossil Phoenix Ridge in the Drake Passage show that magmatism continued for at least 2 Ma after the cessation of spreading at 3.3 ± 0.2 Ma. The Phoenix Ridge lavas are incompatible element-enriched relative to average MORB and show an increasing...
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Online Access: | https://oceanrep.geomar.de/id/eprint/10116/ https://oceanrep.geomar.de/id/eprint/10116/2/2011_Haase_Hauff_etal_ChemGeo.pdf https://oceanrep.geomar.de/id/eprint/10116/3/2011_Haase_Hauff_etal_ChemGeo_SuppMat.xls https://doi.org/10.1016/j.chemgeo.2010.11.002 |
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ftoceanrep:oai:oceanrep.geomar.de:10116 2023-10-09T21:51:04+02:00 Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage Haase, Karsten Beier, Christoph Fretzdorff, Susanne Leat, P. T. Livermore, R. A. Barry, T. L. Pearce, J. A. Hauff, Folkmar 2011 text other https://oceanrep.geomar.de/id/eprint/10116/ https://oceanrep.geomar.de/id/eprint/10116/2/2011_Haase_Hauff_etal_ChemGeo.pdf https://oceanrep.geomar.de/id/eprint/10116/3/2011_Haase_Hauff_etal_ChemGeo_SuppMat.xls https://doi.org/10.1016/j.chemgeo.2010.11.002 en eng Elsevier https://oceanrep.geomar.de/id/eprint/10116/2/2011_Haase_Hauff_etal_ChemGeo.pdf https://oceanrep.geomar.de/id/eprint/10116/3/2011_Haase_Hauff_etal_ChemGeo_SuppMat.xls Haase, K., Beier, C., Fretzdorff, S., Leat, P. T., Livermore, R. A., Barry, T. L., Pearce, J. A. and Hauff, F. (2011) Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage. Chemical Geology, 280 . pp. 115-125. DOI 10.1016/j.chemgeo.2010.11.002 <https://doi.org/10.1016/j.chemgeo.2010.11.002>. doi:10.1016/j.chemgeo.2010.11.002 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2011 ftoceanrep https://doi.org/10.1016/j.chemgeo.2010.11.002 2023-09-24T23:21:40Z New 40Ar-39Ar ages of 5.6 to 1.3 Ma for lavas from the fossil Phoenix Ridge in the Drake Passage show that magmatism continued for at least 2 Ma after the cessation of spreading at 3.3 ± 0.2 Ma. The Phoenix Ridge lavas are incompatible element-enriched relative to average MORB and show an increasing enrichment with decreasing age, corresponding to progressively decreasing degrees of partial melting of spinel peridotite after spreading stopped. The low-degree partial melts increasingly tap a mantle source with radiogenic Sr and Pb but unradiogenic Nd isotope ratios implying an ancient enrichment. The post-spreading magmas apparently form by buoyant ascent of enriched and easily fusible portions of the upper mantle. Only segments of fossil spreading ridges underlain by such enriched and fertile mantle show post-spreading volcanism frequently forming bathymetric highs. The Phoenix Ridge lavas belong to the Pacific, rather than the Atlantic, mantle domain in regional Sr-Nd-Pb space. Our new data show that the southern Pacific Ocean mantle is heterogeneous containing significant enriched portions that are preferentially tapped at low melt fractions. Isotopic mapping reveals that Pacific-type upper mantle flows eastward through Drake Passage and surrounds the subducting Phoenix Plate beneath the Bransfield Basin. Article in Journal/Newspaper Drake Passage OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Drake Passage Pacific Chemical Geology 280 1-2 115 125 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
New 40Ar-39Ar ages of 5.6 to 1.3 Ma for lavas from the fossil Phoenix Ridge in the Drake Passage show that magmatism continued for at least 2 Ma after the cessation of spreading at 3.3 ± 0.2 Ma. The Phoenix Ridge lavas are incompatible element-enriched relative to average MORB and show an increasing enrichment with decreasing age, corresponding to progressively decreasing degrees of partial melting of spinel peridotite after spreading stopped. The low-degree partial melts increasingly tap a mantle source with radiogenic Sr and Pb but unradiogenic Nd isotope ratios implying an ancient enrichment. The post-spreading magmas apparently form by buoyant ascent of enriched and easily fusible portions of the upper mantle. Only segments of fossil spreading ridges underlain by such enriched and fertile mantle show post-spreading volcanism frequently forming bathymetric highs. The Phoenix Ridge lavas belong to the Pacific, rather than the Atlantic, mantle domain in regional Sr-Nd-Pb space. Our new data show that the southern Pacific Ocean mantle is heterogeneous containing significant enriched portions that are preferentially tapped at low melt fractions. Isotopic mapping reveals that Pacific-type upper mantle flows eastward through Drake Passage and surrounds the subducting Phoenix Plate beneath the Bransfield Basin. |
format |
Article in Journal/Newspaper |
author |
Haase, Karsten Beier, Christoph Fretzdorff, Susanne Leat, P. T. Livermore, R. A. Barry, T. L. Pearce, J. A. Hauff, Folkmar |
spellingShingle |
Haase, Karsten Beier, Christoph Fretzdorff, Susanne Leat, P. T. Livermore, R. A. Barry, T. L. Pearce, J. A. Hauff, Folkmar Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
author_facet |
Haase, Karsten Beier, Christoph Fretzdorff, Susanne Leat, P. T. Livermore, R. A. Barry, T. L. Pearce, J. A. Hauff, Folkmar |
author_sort |
Haase, Karsten |
title |
Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
title_short |
Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
title_full |
Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
title_fullStr |
Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
title_full_unstemmed |
Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage |
title_sort |
magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil phoenix ridge, drake passage |
publisher |
Elsevier |
publishDate |
2011 |
url |
https://oceanrep.geomar.de/id/eprint/10116/ https://oceanrep.geomar.de/id/eprint/10116/2/2011_Haase_Hauff_etal_ChemGeo.pdf https://oceanrep.geomar.de/id/eprint/10116/3/2011_Haase_Hauff_etal_ChemGeo_SuppMat.xls https://doi.org/10.1016/j.chemgeo.2010.11.002 |
geographic |
Drake Passage Pacific |
geographic_facet |
Drake Passage Pacific |
genre |
Drake Passage |
genre_facet |
Drake Passage |
op_relation |
https://oceanrep.geomar.de/id/eprint/10116/2/2011_Haase_Hauff_etal_ChemGeo.pdf https://oceanrep.geomar.de/id/eprint/10116/3/2011_Haase_Hauff_etal_ChemGeo_SuppMat.xls Haase, K., Beier, C., Fretzdorff, S., Leat, P. T., Livermore, R. A., Barry, T. L., Pearce, J. A. and Hauff, F. (2011) Magmatic evolution of a dying spreading axis: evidence for the interaction of tectonics and mantle heterogeneity from the fossil Phoenix Ridge, Drake Passage. Chemical Geology, 280 . pp. 115-125. DOI 10.1016/j.chemgeo.2010.11.002 <https://doi.org/10.1016/j.chemgeo.2010.11.002>. doi:10.1016/j.chemgeo.2010.11.002 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.chemgeo.2010.11.002 |
container_title |
Chemical Geology |
container_volume |
280 |
container_issue |
1-2 |
container_start_page |
115 |
op_container_end_page |
125 |
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1779314166374334464 |