An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago
The Crozet archipelago, located midway between Madagascar and Antarctica, constitutes the emerged part of the easternmost bank of the Crozet plateau, which lies upon upper Cretaceous oceanic seafloor derived from the Southeast Indian Ridge. It forms an elongated chain of five islands and islets, div...
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ftunivpadovairis:oai:www.research.unipd.it:11577/2684869 2024-04-21T07:49:06+00:00 An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago MEYZEN, CHRISTINE MARIE MARZOLI, ANDREA BELLIENI, GIULIANO Meyzen, CHRISTINE MARIE Marzoli, Andrea Bellieni, Giuliano 2013 ELETTRONICO http://hdl.handle.net/11577/2684869 http://fallmeeting.agu.org/2013/ eng eng ispartofbook:AGU Fall meeting 2013 AGU Fall meeting 2013 firstpage:F2671 lastpage:F2671 numberofpages:1 http://hdl.handle.net/11577/2684869 http://fallmeeting.agu.org/2013/ info:eu-repo/semantics/conferenceObject 2013 ftunivpadovairis 2024-03-28T01:44:50Z The Crozet archipelago, located midway between Madagascar and Antarctica, constitutes the emerged part of the easternmost bank of the Crozet plateau, which lies upon upper Cretaceous oceanic seafloor derived from the Southeast Indian Ridge. It forms an elongated chain of five islands and islets, divided into two groups: an older eastern island group (< 9 Ma) composed by large-scale volcanic landmasses (i.e. East and Possession islands) and a younger western one (< 5.5 Ma) with pint-sized islands. The whole region exhibits some of the most typical gravimetric, seismic and bathymetric characteristics associated with upwelling hotter than average mantle including: a geoid high, a topographic swell, a deep low-velocity zone (up to 2350 km), an anomalous heat flow and a thickened crust (10–16.5 km). Most of these features are exacerbated by the near stationary absolute motion of the Antarctic plate. However, since thirty years, the chemical composition of Crozet archipelago magmas has beneficiated from little interest compared to that of other Earth’s hotspots. Because of the occurrence of both a thick and old lithosphere and of a near stagnant absolute plate motion, new data from the Crozet archipelago magmatic record will provide new critical perspective on oceanic island building processes. The data presented here are based on a basaltic suite of ~ 25 samples collected by a “Terres Australes et Antarctiques Francaises” expedition in 1969 from the northern part of East Island. Our alkali basalts from the Crozet archipelago are distinct from other oceanic within-plate magmatic rocks in showing ubiquitous large depletions in LILE with respect to other incompatible elements, although these rocks constitute one of the most incompatible-element-enriched suites among Earth’s oceanic island basalts (OIB). The similarity of their trace element ratios and parallelism of their rare earth element patterns indicate: (1) a mantle source homogeneity over at least 1 Ma; (2) an uniformity of the melting conditions (i.e. ... Conference Object Antarc* Antarctic Antarctica Antarctique* Possession Islands Padua Research Archive (IRIS - Università degli Studi di Padova) |
institution |
Open Polar |
collection |
Padua Research Archive (IRIS - Università degli Studi di Padova) |
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ftunivpadovairis |
language |
English |
description |
The Crozet archipelago, located midway between Madagascar and Antarctica, constitutes the emerged part of the easternmost bank of the Crozet plateau, which lies upon upper Cretaceous oceanic seafloor derived from the Southeast Indian Ridge. It forms an elongated chain of five islands and islets, divided into two groups: an older eastern island group (< 9 Ma) composed by large-scale volcanic landmasses (i.e. East and Possession islands) and a younger western one (< 5.5 Ma) with pint-sized islands. The whole region exhibits some of the most typical gravimetric, seismic and bathymetric characteristics associated with upwelling hotter than average mantle including: a geoid high, a topographic swell, a deep low-velocity zone (up to 2350 km), an anomalous heat flow and a thickened crust (10–16.5 km). Most of these features are exacerbated by the near stationary absolute motion of the Antarctic plate. However, since thirty years, the chemical composition of Crozet archipelago magmas has beneficiated from little interest compared to that of other Earth’s hotspots. Because of the occurrence of both a thick and old lithosphere and of a near stagnant absolute plate motion, new data from the Crozet archipelago magmatic record will provide new critical perspective on oceanic island building processes. The data presented here are based on a basaltic suite of ~ 25 samples collected by a “Terres Australes et Antarctiques Francaises” expedition in 1969 from the northern part of East Island. Our alkali basalts from the Crozet archipelago are distinct from other oceanic within-plate magmatic rocks in showing ubiquitous large depletions in LILE with respect to other incompatible elements, although these rocks constitute one of the most incompatible-element-enriched suites among Earth’s oceanic island basalts (OIB). The similarity of their trace element ratios and parallelism of their rare earth element patterns indicate: (1) a mantle source homogeneity over at least 1 Ma; (2) an uniformity of the melting conditions (i.e. ... |
author2 |
Meyzen, CHRISTINE MARIE Marzoli, Andrea Bellieni, Giuliano |
format |
Conference Object |
author |
MEYZEN, CHRISTINE MARIE MARZOLI, ANDREA BELLIENI, GIULIANO |
spellingShingle |
MEYZEN, CHRISTINE MARIE MARZOLI, ANDREA BELLIENI, GIULIANO An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
author_facet |
MEYZEN, CHRISTINE MARIE MARZOLI, ANDREA BELLIENI, GIULIANO |
author_sort |
MEYZEN, CHRISTINE MARIE |
title |
An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
title_short |
An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
title_full |
An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
title_fullStr |
An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
title_full_unstemmed |
An assessment of the record in compositional variations from mantle source to magmatism at East Island, Crozet archipelago |
title_sort |
assessment of the record in compositional variations from mantle source to magmatism at east island, crozet archipelago |
publishDate |
2013 |
url |
http://hdl.handle.net/11577/2684869 http://fallmeeting.agu.org/2013/ |
genre |
Antarc* Antarctic Antarctica Antarctique* Possession Islands |
genre_facet |
Antarc* Antarctic Antarctica Antarctique* Possession Islands |
op_relation |
ispartofbook:AGU Fall meeting 2013 AGU Fall meeting 2013 firstpage:F2671 lastpage:F2671 numberofpages:1 http://hdl.handle.net/11577/2684869 http://fallmeeting.agu.org/2013/ |
_version_ |
1796953186099003392 |