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| Titel |
The Architecture of the European-Mediterranean Lithosphere seen in osmium isotopes |
| VerfasserIn |
Jose Maria Gonzalez-Jimenez, Carlos Villaseca, William L. Griffin, Zoltán Konc, Elena Belousova, Eumenio Anochea, Suzanne Y. O'Reilly, Carlos J. Garrido, Norman J. Pearson, Fernando Gervilla |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077502
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| Zusammenfassung |
| A growing body of work, based on the study of -Pb ages of magmatic zircons, Hf model ages
of inherited zircons and whole-rock Nd model ages of crustal igneous and metamorphic rocks
have provide constrain forthe timing of formation and evolution of the Iberian microplate.
However, there is little robust information on the age of its underlying mantle; it is the
missing key for a full understanding of the geological framework of the Iberian
microplate. In this work we have now been filled this gap by analysing in-situ, using
LA-MC-ICPMS, the Re-Os isotope systematics of sulfides in spinel herzolites and
wehrlites from the olivine melilite mar of El Aprisco in the Calatrava Volcanic
Field, central Spain. The 68 analysed sulfides (-¥50 μm) were enclosed in olivine
and pyroxenes, rarely at the triple junctions between the main silicates, and more
commonly in the interstitial glass. However, there is no difference in Re-Os isotope
compositions between included and interstitial sulfides. Re-depletion model ages (TRD)
calculated for these sulfides show magmatic events in the mantle at ~1.8, 1.1, 0.9,
0.6 and 0.3 Ga, which are correlated with main events of growth of the Iberian
crust. A synthesis of Re-depletion model ages (TRD) for both whole-rock samples
and in situ-analysed of individual sulfides from mantle-derived rocks, including
xenoliths and peridotite massifs, widesrpread thorough the Mediterranean area
show the existence of different mantle domains across the Mediterranean. Thus, the
Re-Os data identify identify the existence of a common Paleo-Proterozoic (~ 1.8
Ga) mantle on both sides of the Mediterranean realm, and an older (~2.2-2.6 Ga)
lithospheric mantle sitting within the more recent Maghrebide-Appenine- Betic front
generated during the Alpine-Betic orogeny. The Mediterranean basin may contain
several buoyant Archean microplates, which could have impeded the northward
movement of Africa and contributed to complex tectonics in the Mediterannean basin. |
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