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TitreZircon age determinations for the Ladakh batholith at Chumathang (Northwest India): Implications for the age of the India-Asia collision in the Ladakh Himalaya
AuteurSt-Onge, M R; Rayner, N; Searle, M P
SourceTectonophysics vol. 495, issue 3-4, 2010 p. 171-183, https://doi.org/10.1016/j.tecto.2010.09.010
Année2010
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090346
ÉditeurElsevier
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.tecto.2010.09.010
Mediapapier; en ligne; numérique
Formatspdf
Lat/Long OENS 76.0000 79.0000 34.5000 33.0000
Sujetscaractéristiques structurales; tectonique de plaques; milieux tectoniques; interprétations tectoniques; datation radiométrique; datation au uranium-plomb; roches ignées; batholites; Batholite de Ladakh ; Plaque Indienne; Plaque de l'Asie; Zone d'Indus Structure ; tectonique; géologie structurale; géochronologie
Illustrationslocation maps; photographs; photomicrographs; charts; Concordia diagrams
ProgrammeBases de données couvrant les trois territoires (Géologie du substratum rocheux), GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
The Ladakh batholith is part of the > 2500 km long Trans-himalayan batholith that forms the southern margin of the Asian plate and is unconformably overlain by the post-collision Indus Molasse Group sedimentary rocks. We present new U-Pb ID-TIMS zircon ages from a host hornblende-bearing granodiorite (57.7 ± 0.2 Ma) and a later intrusive leucocratic granite dyke (47.1 ± 0.1 Ma) from the Ladakh batholith at Chumathang in northeast Ladakh, India. Subduction-related granodioritic magmatism in eastern Ladakh is dominantly of late Paleocene - early Eocene age. The age of the Chumathang dyke gives a maximum age constraint on Indus Molasse Group basin formation along the northern margin of the Indus Suture Zone and a minimum age constraint on the India-Asia collision. Together with the age of youngest marine sedimentary rocks in the suture zone (Nummulitic Limestone; 50.5 Ma) we propose that by late Ypresian - early Lutetian (early Eocene) time, the two continents had collided, sedimentation in the suture zone became purely continental and subduction-related igneous intrusions had ceased.
GEOSCAN ID261531