Citation:

Hu, P.Y., Zhai, Q.G., Cawood, P.A., Zhao, G.C., Wang, J., Tang, Y., Zhu, Z.C., Wang, W., & Wu, H. (2021). Cambrian magmatic flare-up, central tibet: magma mixing in proto-tethyan arc along north gondwanan margin. Geological Society of America Bulletin. 133(9-10), 2171–2188.

Literature information
Title Cambrian magmatic flare-up, central Tibet: Magma mixing in proto-Tethyan arc along north Gondwanan margin
Year 2021
Description

Accompanying Gondwana assembly, widespread but diachronous Ediacaran–early Paleozoic magmatism of uncertain origin occurred along the supercontinent’s proto- Tethyan margin. We report new geochemical, isotopic, and geochronological data for Cambrian magmatic rocks (ca. 500 Ma) from the Gondwana-derived North Lhasa terrane, located in the present-day central Tibetan Plateau. The magmatic rocks are composed of basalts, gabbros, quartz monzonites, granitoids (with mafic microgranular enclaves), and rhyolites. Nd-Hf isotopic and whole-rock geochemical data indicate that these rocks were probably generated by mixing of mantlederived mafic and crust-derived felsic melts. The mantle end-member volumes of mafic, intermediate, and felsic rocks are ∼75%–100%, 50%–60%, and 0–30%, respectively. Integration of our new data with previous studies suggests that the North Lhasa terrane experienced long-term magmatism through the Ediacaran to Ordovician (ca. 572–483 Ma), with a magmatic flare-up at ca. 500 Ma. This magmatism, in combination with other Ediacaran–early Paleozoic magmatism along the proto-Tethyan margin, was related to an Andean-type arc, with the magmatic flare-up event related to detachment of the oceanic slab following collisional accretion of Asian microcontinental fragments to northern Gondwana. Diachroneity of the proto-Tethyan arc system along the northern Gondwanan margin (ca. 581–531 Ma along the Arabian margin and ca. 512–429 Ma along the Indian-Australian margin) may have been linked to orogenesis within Gondwana. The North Lhasa terrane was probably involved in both Arabian and Indian-Australian proto-Tethyan Andeantype orogens, based on its paleogeographic location at the northern end of the East African orogen.

PDF This literature is not included PDF(How to submit?)