Shrimp U–Pb zircon geochronology, geochemistry, and Nd–Sr isotopic study of contrasting granites in the Emeishan large igneous province, SW China

Origin of the early Permian Wajilitag igneous complex and associated Fe–Ti oxide mineralization in the Tarim large igneous province, NW China

“…In addition, the Tzr values for the syenites range from 843 to 981°C, consistent with those of basaltic magma-fractionated A-type granites in the Emeishan LIP (Zhong et al, 2007).…”

CA-TIMS zircon U–Pb dating of felsic ignimbrite from the Binchuan section: Implications for the termination age of Emeishan large igneous province

“…Constraining the age of this boundary is therefore important but the radiometric ages of claystones near the G-L boundary at GSSP (Global Boundary Stratotype Section and Point) in the Penglaitan section have shown that these deposits are redeposited clastic rocks rather than acidic Pb correlation of +0.9. Present day Th/U ratio is calculated from radiogenic Zhou et al (2002Zhou et al ( , 2006Zhou et al ( , 2008, Fan et al (2004), Zhong and Zhu (2006), He et al (2007), Luo et al (2007), Shellnutt and Zhou (2007), Zhong et al (2007), Xu et al (2008, Shellnutt et al (2012) Ar ages underestimate the emplacement age of the igneous rocks in the Emeishan LIP. tuffs or ashes, and are thus not suitable for the age determination of the G-L boundary (Zhong et al, 2013).…”

“…Although the Emeishan LIP has been dated by 40 Ar dating results yield MesozoicCenozoic ages (Ali et al, 2004;Lo et al, 2002), most likely as a result of open system behavior of the analyzed minerals and rocks due to Mesozoic and Cenozoic thermotectonic events in the western Yangtze Block. Consequently, the timing of the Emeishan LIP magmatism is mainly constrained by U-Pb zircon dates from mafic-ultramafic and felsic intrusions (e.g., Shellnutt et al, 2012;Xu et al, 2008;Zhong et al, 2007Zhong et al, , 2009Zhong et al, , 2011Zhou et al, 2002). It is assumed that these intrusive bodies are genetically related to the Emeishan LIP, and the acquired U-Pb ages imply that the main phase of the Emeishan LIP took place at 257-260 Ma (Shellnutt et al, 2012;Xu et al, 2008;Zhou et al, 2002).…”

Zircon U-Pb age, geochemical, and Sr-Nd-Pb isotopic constraints on the origin of alkaline intrusions in eastern Shandong Province, China

“…We use the wholerock two-stage Nd model ages to infer the possible age of the source. The two-stage Nd model ages (T DM2 =2.02-2.25 Ga) At present, there compete various petrogenetic models for the generation of alkaline felsic rocks (e.g., syenite and A-type granite) (Yang et al 2005a, b;Zhong et al 2007;Liu et al 2008a, b), such as (1) partial melting of lower-crustal rocks under the fluxing of volatiles, (2) fractionation of mantlederived magmas with or without crustal contamination, (3) mixing of basic and silicic melts and their differentiates, as well as, (4) partial melting of an enriched lithospheric mantle beneath an orogenic belt, due to hybridisation of melts derived from foundered lower crustal eclogite. Among them, the insignificant variations in Sr-Nd isotopes with SiO 2 for the alkaline rocks (Fig.…”