Geochronology and geochemistry of basaltic lavas in the Dongbo and Purang ophiolites of the Yarlung-Zangbo Suture zone: Plume-influenced continental margin-type oceanic lithosphere in southern Tibet

Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture‐zone magnetic anomalies

“…The Dongbo peridotite massif covers an area of ~400 km 2 identified by aeromagnetic data [ Jiang et al ., ; Yang et al ., ], but about one third of this massif is covered by Neogene‐Quaternary sediments (Figure b). The peridotite massif is in fault contact with surrounding Late Triassic to Late Cretaceous mélanges, consisting of carbonates, clastic rocks, basic lavas, and cherts [ F. Liu et al ., ]. Gabbro and pyroxenite dykes that intruded the peridotites yield crystallization ages of ~130–128 Ma (U‐Pb dating on zircons) [ Xiong et al ., ].…”

Melt evolution of upper mantle peridotites and mafic dikes in the northern ophiolite belt of the western Yarlung Zangbo suture zone (southern Tibet)

“…Geodynamic models explaining the geochemical evolution of the YZSZ ophiolites, their tectonic origin of magmatic construction within a broad Neotethys oceanic realm, and the paleography of this Mesozoic-Cenozoic ocean basin vary significantly Dai et al, 2013;C. Liu et al, 2014;Liu et al, 2015a;Gong et al, 2016;Lian et al, 2016;Xiong et al, 2016). These variations stem largely from (1) widespread, contractional, strike-slip and extensional deformation along and across the YZSZ that occurred during and after the initial India-Asia collision that significantly modified the primary structures and the original distribution of lithological units; (2) original heterogeneities in upper mantle compositions and in their crustal derivatives in the oceanic lithosphere, which developed in different tectonic settings within the Neotethys Ocean basin; and (3) major changes in intraocean basin tectonics and continental margin evolution of the Neotethys Ocean along its >3000 km length from the west to the east.…”

“…Disseminated and massive chromitite deposits are commonly associated with dunite occurrences within the harzburgites in the SB massifs. Geochemical and petrogenetic modeling of the melt evolution of the Purang and Dongbo peridotites has shown that they were the products of partial melting of garnet-bearing spinel lherzolites in the subcontinental lithospheric mantle below northern India or beneath the Zhongba terrane (Liu et al, 2015a).…”

Mineralogy, Petrology and Geochemistry of Peridotites from the Northern Ophiolititc Sub‐belt, Western Yarlung Zangbo Suture Zone, Tibet

“…These remnants of ancient oceanic lithosphere have recorded important information for the magmatic, tectonic and metamorphic processes associated with the evolution of ancient oceanic basins (Bezard et al, 2011;Dilek and Furnes, 2014;Liu et al, 2014;Saka et al, 2014;Tang et al, 2014). Peridotites are usually considered to be the solid residues of oceanic upper mantle left behind after varied degree of mantle meting and crust-mantle segregation (Aldanmaz et al, 2009).…”

“…Cretaceous ophiolitic massifs crop out discontinuously along the Yarlung Zangbo Suture Zone (YZSZ) (Allegre et al, 1984;Dubois-Cote et al, 2005;Guilmette et al, 2009;Liu et al, 2014;McDermid et al, 2002). Ophiolitic belts along the Yarlung Zangbo suture zone are typically divided into eastern (e.g., Luobusa ophiolite), central (e.g., Xigaze ophiolite) and western (e.g., Dongbo and Purang ophiolites) segments (Dubois-Cote et al, 2005;DuboisCote et al, 2005).…”