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| Titel |
Metamorphic history and geodynamic significance of the Early Cretaceous Sabzevar granulites (Sabzevar structural zone, NE Iran) |
| VerfasserIn |
M. Nasrabady, F. Rossetti, T. Theye, G. Vignaroli |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 2, no. 2 ; Nr. 2, no. 2 (2011-11-11), S.219-243 |
| Datensatznummer |
250000596
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| Publikation (Nr.) |
 copernicus.org/se-2-219-2011.pdf |
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| Zusammenfassung |
| The Iranian ophiolites are part of the vast orogenic suture zones that mark
the Alpine-Himalayan convergence zone. Few petrological and geochronological
data are available from these ophiolitic domains, hampering a full
assessment of the timing and regimes of subduction zone metamorphism and
orogenic construction in the region. This paper describes texture,
geochemistry, and the pressure-temperature path of the Early Cretaceous mafic
granulites that occur within the Tertiary Sabzevar ophiolitic suture zone of
NE Iran. Whole rock geochemistry indicates that the Sabzevar granulites are
likely derived from a MORB-type precursor. They are thus considered as
remnants of a dismembered dynamo-thermal sole formed during subduction of a
back-arc basin (proto-Sabzevar Ocean) formed in the upper-plate of the
Neotethyan slab. The metamorphic history of the granulites suggests an
anticlockwise pressure-temperature loop compatible with burial in a hot
subduction zone, followed by cooling during exhumation. Transition from a
nascent to a mature stage of oceanic subduction is the geodynamic scenario
proposed to accomplish for the reconstructed thermobaric evolution.
When framed with the regional scenario, results of this study point to
diachronous and independent tectonic evolutions of the different ophiolitic
domains of central Iran, for which a growing disparity in the timing of
metamorphic equilibration and of pressure-temperature paths can be expected
to emerge with further investigations. |
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