Early Yanshanian post-orogenic granitoids in the Nanling region?? Petrological constraints and geodynamic settings

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

“…Jurassic: Th~107 Ma Tunchang-Fengmu intrusive rocks contain 168-160 Ma magmatic zircons, which are consistent with the widespread occurrence of 165-155 Ma I-and A-type granites and syenites following the initiation of intraplate basaltic and/or bimodal igneous magmatism at 190-170 Ma in central South China (e.g., Zhao et al, 1998Zhao et al, , 2001Chen et al, 2002;Li et al, 2003Li et al, , 2004aLi et al, , b, 2007Wang et al, , 2008cHe et al, 2010;Zhu et al, 2010) and Jurassic gabbros in the Hainan area (e.g., Liu, 1991). These Jurassic igneous rocks are considered to represent a major anorogenic magmatic event linked to foundering of an early Mesozoic subducted flat-slab beneath the SE China continent or lithospheric or back-arc extension induced by Jurassic subduction of the Paleo-Pacific Plate (e.g., Zhou et al, 2006a;He et al, 2010;Zhao et al, 2012).…”

Relict Proterozoic basement in the Nanling Mountains (SE China) and its tectonothermal overprinting

“…The Guidong complex is a multistage intrusive granitic complex, with different members formed during both Indosinian and Yanshanian time. It is a late orogenic to postorogenic granitic complex, related to the extensional tectonic setting that developed after the Indosinian event [Chen et al, 2002]. Therefore the coexistence of Indosinian and Yanshanian granites here may reflect the change from Indosinian to Yanshanian tectonics in this region.…”

Phanerozoic tectonics of the South China Block: Key observations and controversies

“…In contrast, the Jurassic sequence to the east of the fault is dominated by the lower-middle Jurassic terrestrial siliciclastics (only some remnants of early Jurassic neritic rocks are preserved in the Meizhou area of eastern Guangdong). The middle Jurassic bimodal volcanic sequence is additionally observed in western Fujian, southern Jiangxi and eastern Hunan Provinces in the eastern SCB along the E-W trending Nanling Range (e.g., Chen et al, 1999Chen et al, , 2002aChen et al, , 2002bLi et al, 2003Li et al, , 2004Deng et al, 2004a;Wang et al, 2005bWang et al, , 2008Chen et al, 2008a;Shu et al, 2008aShu et al, , b, 2009a. In the eastern SCB, upper Jurassic strata are commonly absent with the exception of sparse exposures in the Yongding-Meizhou basin (e.g., Guangdong BGMR, 1988;Shu et al, 2009a, b).…”

“…One is a roughly east-westerly trending volcanic zone along the Nanling Range from southern Hunan (e.g., Daoxian, Ningyuan and Changchengling) through southern Jiangxi (e.g, Linjiang-Dongkeng and Huichang) and finally to southeastern Fujian (e.g., Pankeng and Meilin) (e.g., Jiangxi BGMR, 1984;Zhao et al, 1998;Chen et al, 1999Chen et al, , 2002aLi et al, 2003Li et al, , 2004Wang et al, 2003bWang et al, , 2005cWang et al, , 2005bDeng et al, 2004a;Xie et al, 2005a;Zhou et al, 2005Zhou et al, , 2006aZhu et al, 2005;Chen et al, 2008a;Yu et al, 2009bYu et al, , 2010bHe et al, 2010). These rocks formed in the early-middle Jurassic (dominantly at , and are compose of 45% basaltic and 50% rhyolitic rocks along with a small amount of andesite (e.g., Zhao et al, 1998;Chen et al, 1999Chen et al, , 2002aWang et al, 2003bWang et al, , 2005b. They are spatially associated with subsequently emplaced calc-alkaline granite, A-type granite and syenite (e.g., Zhou and Li, 2000;Li et al, 2003Li et al, , 2004Li et al, , 2009cXie et al, 2005a;Zhou et al, 2005).…”

“…Chen et al (2008b) suggested that the Jurassic mantle beneath the Cathaysia Block was rather homogeneous and undisturbed, and hence was not affected by the paleo-Pacific subduction system. The postorogenic extension of the Indosinian orogeny between the SCB and Indochina Block might be the cause for vast Jurassic granitic magmatism in the eastern SCB (e.g., Chen et al, 2002aChen et al, , 2002bWang and Zhou, 2002;Zhou et al, 2006aZhou et al, , 2006bZhou et al, , 2007Chen et al, 2008a). Zhou et al (2006aZhou et al ( , 2006bZhou et al ( , 2007) suggested that (1) the tectonic transformation of the SCB from the Tethyan to Pacific regime initially occurred in the early Jurassic (ca.…”