Petrogenesis and tectonic implications of Early Cretaceous S- and A-type granites in the northwest of the Gan-Hang rift, SE China

Zircon U–Pb, molybdenite Re–Os and muscovite Ar–Ar isotopic dating of the Xitian W–Sn polymetallic deposit, eastern Hunan Province, South China and its geological significance

“…However, some of them are recently classified as fractionationed I-type granites or A-type granites (Zhou and Li, 2000;Ma et al, 2004;Fu et al, 2004a;Bai et al, 2005;Jiang et al, 2005Jiang et al, , 2006Jiang et al, , 2009Jiang et al, , 2011Li et al, 2007e, 2014aHuang et al, 2011;Zhou et al, 2013). All these rocks constitute melts generated in an anorogenic, intraplate environment where regional lithospheric extension occurred in the Early Yanshanian Jiang et al, 2009Jiang et al, , 2011Zhou et al, 2013).…”

Late Early Cretaceous adakitic granitoids and associated magnesian and potassium‐rich mafic enclaves and dikes in the Tunchang–Fengmu area, Hainan Province (South China): Partial melting of lower crust and mantle, and magma hybridization

“…Cretaceous: the~107 Ma Tunchang-Fengmu suite contains 119-127 Ma magmatic zircons, which are consistent with the widespread presence of~122-129 Ma A-type granites in the interior of South China (e.g., Wang et al, 2005b) and lithospheric extension that may have resulted from the roll-back of subducted Paleo-Pacific plate (e.g., Wong et al, 2009;Jiang et al, 2011). In this scenario, the resulting continuous upwelling of unmetasomatized asthenospheric mantle would have triggered partial melting of overlying subducted oceanic sediment-metasomatized asthenospheric and lithospheric mantle or relatively juvenile lithospheric mantle (e.g., Pe-Piper et al, 2009;Jiang et al, 2011) or interactions between melts derived from metasomatized asthenospheric mantle and lithospheric mantle (e.g., Chung et al, 1994;Xu et al, 2005).…”

“…However, Wang et al (2007d) and Zhang et al (2011) suggest that the Middle Permian-Triassic evolution of South China was related to the amalgamation of the Indochina and South China Blocks as the result of Paleotethys oceanic plate subduction and subsequent continental collision. Irrespective of these different viewpoints on the Middle Permian-Triassic evolution of South China, there has been a consensus that subduction of the Paleo-Pacific Plate and associated geodynamic processes (slab foundering or roll back or back-arc extension) played an important role in the Jurassic-Cretaceous evolution of the area (e.g., Xu et al, 1999a;Zhou and Li, 2000;Wang et al, 2005b;Zhou et al, 2006a;Li et al, 2006a;Jiang et al, 2009Jiang et al, , 2011He et al, 2010;Zhao et al, 2012). These events can readily account for the combination of asthenospheric and lithosperic mantle wedge peridodite sources for the Tungchang-Fengmu intrusive suite and for their metasomatism by subducted oceanic sediments.…”

“…In this scenario, the resulting continuous upwelling of unmetasomatized asthenospheric mantle would have triggered partial melting of overlying subducted oceanic sediment-metasomatized asthenospheric and lithospheric mantle or relatively juvenile lithospheric mantle (e.g., Pe-Piper et al, 2009;Jiang et al, 2011) or interactions between melts derived from metasomatized asthenospheric mantle and lithospheric mantle (e.g., Chung et al, 1994;Xu et al, 2005). Basaltic magmas generated by these processes would have underplated, thickened and reworked the existing lower crust to form a new lower crust that itself was subject to melting as a result of continued basaltic magma underplating (Annen et al, 2006).…”

Early Cretaceous potassic volcanic rocks in the Jiangnan Orogenic Belt, East China: Crustal melting in response to subduction of the Pacific–Izanagi ridge?

“…Some geologists invoked a lithospheric delamination model to interpret the removal of the cold and thick lithosphere beneath the North China Craton (Wu et al, 2002;Gao et al, 2008), and even in the lower Yangtze region (e.g., Xu et al, 2002, Wang et al, 2006, 2007a. In SE China, the origin of the Mesozoic igneous events and mineralization was attributed to flat-slab subduction and subsequent foundering of the subducting slab Li et al, , 2013, or else formed in a back-arc extensional tectonic setting (Yan et al, 2008;Liu et al, 2010;Jiang et al, 2011;Tang et al, 2013;Xie et al, 2011;Yang et al, 2014). Alternatively, some recent studies have proposed a genetic link between the Mesozoic magmatism and mineralization in East Asia related to a slab window coupled with ridge subduction (Sun et al, 2007(Sun et al, , 2010Li et al, 2011Li et al, , 2012.…”