Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Ergebnis 11 von 372

Details

Autor(en) / Beteiligte
Titel
Discovery of a dismembered metamorphic sole in the Saga ophiolitic mélange, South Tibet: Assessing an Early Cretaceous disruption of the Neo-Tethyan supra-subduction zone and consequences on basin closing
Ist Teil von
  • Gondwana research, 2012-09, Vol.22 (2), p.398-414
Ort / Verlag
Elsevier B.V
Erscheinungsjahr
2012
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
  • Blocks of strongly foliated garnet- and clinopyroxene-bearing amphibolites have recently been discovered in the Saga ophiolitic mélange, South Tibet. The Saga ophiolitic mélange is a sheared serpentinite matrix mélange that crops out along the Yarlung Zangbo Suture Zone (YZSZ), South Tibet. The YZSZ is the youngest and the southernmost of all sutures stretching across the Tibetan Plateau and contains the remnants of the Neo-Tethys ocean that once separated India from the Lhasa block. The garnet- and clinopyroxene-bearing amphibolite blocks are interpreted as parts of a dismembered sub-ophiolitic metamorphic sole. They are made mainly of hornblende, diopside and garnet and were strongly metasomatized during retrogression. Thermobarometry and 40Ar/39Ar dating on hornblende indicate that they were metamorphosed to peak conditions in excess of 12kbar and 850°C between 132 and 127Ma. Major and trace element geochemistry suggest an N- to E-MORB-type protolith, although a back- or inter-arc basin setting cannot be ruled out. This data supports a model in which the back-arc YZSZ ophiolites (central segment) were trapped in a fore-arc setting by the inception of a subduction at the back-/inter-arc ridge. The cause of this important Early Cretaceous tectonic event might be the presence of an oceanic plateau or hot-spot tracks in the Neo-Tethys, the collision of the Lhasa and Qiangtang blocks in the North and/or the onset of northward movement of the Indian continent in the South. The proposed conceptual model provides an explanation for the absence (or rarity) of Late Cretaceous ophiolites along the YZSZ which are mostly of Late Jurassic to Early Cretaceous age. [Display omitted] ► A dismembered metamorphic sole has been discovered in the Saga ophiolitic mélange. ► The protolith was basaltic with a N-MORB to BABB affinity. ► Peak conditions were in excess of 12kbar and 800°C around 123–127Ma. ► These rocks recorded the Early Cretaceous disruption of the Neo-Tethyan supra-subduction zone.
Sprache
Englisch
Identifikatoren
ISSN: 1342-937X
eISSN: 1878-0571
DOI: 10.1016/j.gr.2011.10.012
Titel-ID: cdi_crossref_primary_10_1016_j_gr_2011_10_012

Weiterführende Literatur

Empfehlungen zum selben Thema automatisch vorgeschlagen von bX