The generation and reworking of continental crust during early Paleozoic in Gondwanan affinity terranes from the Tibet Plateau

摘要: Abstract The central–south Tibet Plateau represents an important part of the northern segment Gondwana supercontinent during early Paleozoic. Here, we statistically analyze Lu–Hf isotopic data Phanerozoic granitoids from this area, with a view to gain insights on Paleozoic geotectonic evolution margin. zircon granitoids, combined field evidence, provide into involvement Paleo-Mesoproterozoic crustal materials in Plateau. variable Hf data, dominated by negative eHf(t) values, reveal temporal and spatial heterogeneities continental crust. Our results suggest that crust formation occurred at ~1.7 Ga, ~1.4–1.6 Ga, ~1.1–1.3 Ga, ~0.8 Ga, ~0.5–0.6 Ga, ~0.3 Ga. A large volume juvenile crusts Lhasa Himalaya terranes are identified, whereas south Qiangtang terrane east ancient In addition, reworking plays role throughout Reworking old occurs mainly advancing accretionary orogens internal collisional orogens. However, subduction-related magmatism resulted marked excursions composition toward depleted mantle-like features, which produced positive values. Postcollisional associated delamination, orogenic collapse, or lithospheric extension leads melting underthrust fragment, thereby driving collapse eventual rifting generally accompanied relatively minor volumes mafic generation, is consistent our inferences. Therefore, concluded Cambrian–Ordovician magmatic rocks might have developed within postcollision extensional, even rift setting, following Pan-African orogenesis.