Two Late Cretaceous A-type granites related to the Yingwuling W–Sn polymetallic mineralization in Guangdong province, South China: Implications for petrogenesis, geodynamic setting, and mineralization

Abstract

Major and trace elements, whole rock Sr-Nd-Pb isotopes, LA-ICP-MS U-Pb zircon dating, zircon trace elements and Hf isotope data are reported for a suite of A-type granites from Yingwuling pluton in western Guangdong province, South China. Zircon U-Pb ages obtained by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) show that biotite granite and alkali feldspar granite were emplaced in 81.3 ± 0.6 Ma and 80.6 ± 0.5 Ma, respectively. Both of the two suites have the petrographic and geochemical characteristics of A-type granite. These granitic rocks are metaluminous to weakly peraluminous and have pronounced contents of total alkalis (Na 2 O + K 2 O = 7.80-8.84%), Fe 2 O 3 T /MgO and Ga/Al ratios. They exhibit low MgO, CaO and TiO 2 contents, enrichment in some LILEs and HFSEs (except for Zr, Eu and Y), depletion in Ba, Sr, P and Ti. They show A 2 subtype affinity and were probably formed a temperature of ~800°C. The Yingwuling biotite granite has relatively high (87 Sr/ 86 Sr) i ratios of 0.70655 to 0.70928, low ε Nd (t) values of-5.8 to-4.2 and zircon ε Hf (t) values (-5.70-1.37). Whole-rock Nd isotopic and zircon Hf isotopic two-stages model ages mostly vary from 1057 to 1506 Ma. The alkali feldspar granite display bulk rock ε Nd (t) values and (87 Sr/ 86 Sr) i ratios in the range of-6.6 to-6.1 and 0.70640 to 0.71077, respectively, and zircon ε Hf (t) values from-5.44 to 0.54, with Mesoproterozoic T 2DM for both Nd and Hf isotopes. Geochemical and isotopic data indicate the Yingwuling A-type granitic magmas were drived from mantle-crust interaction. Zircon grains of Yingwuling granites have relatively low Eu/Eu* and Ce 4+ /Ce 3+ ratios, indicating low oxygen fugacity. The visible tetrad effect in the Yingwuling granites indicates that it experienced strong fractionation and is close relationship to the W-Sn mineralization. Our new data together with previous published data indicate that Late Mesozoic A-type granitiods or alkaline intrusive rocks in South China can be grouped into four pulses: 195-180 Ma, 180-149 Ma, 136-116 Ma and 110-79 Ma. After 135 Ma, with a change in the polarity of the subduction 3 of paleo-Pacific plate, the crust and lithospheric mantle in eastern China became progressively thinned causing the upwelling of asthenosphere, which would have triggered crustal rocks to partially melt and generate Yingwuling A-type granitic magmas.

Mesozoic multi‐stage W–Sn polymetallic mineralization in the Nanling Range, South China: An example from the Dengfuxian–Xitian ore field

“…The third episode of magmatism and ore formation has been rarely reported in the Nanling Range (Cai et al, ), though we have found ~80 Ma zircons in the Xianghualing Sn polymetallic deposits (Li, Wu, et al, ). However, the Cretaceous (~80 Ma) hydrothermal event that corresponds to some world‐class Sn–W polymetallic deposits has been reported from other parts of South China (Figure ), such as the Gejiu Sn polymetallic ore field in southern Yunnan Province (82.7 ± 0.7 Ma, muscovite 40 Ar– 39 Ar age; Cheng, Mao, & Yang, ); the Yingwuling W–Sn polymetallic mineralization in western Guangdong Province (79–81 Ma, LA‐ICPMS cassiterite and zircon age; Zheng, Mao, Zhao, Zhao, & Yu, ; Zhang et al, ); the Xishan Sn–W deposit in western Guangdong Province (79.4 ± 4.5 Ma, molybdenite Re–Os isochron age; Zhang et al, ); and the Yinyan Sn deposit in western Guangdong Province (78–80 Ma, molybdenite Re–Os model ages; Zheng, Mao, et al, ). Thus, we infer that widespread Cretaceous W–Sn mineralization developed after the Jurassic world‐class W–Sn mineralization in South China, not only in the western Cathaysia Block but also in the Nanling Range.…”

“…Yunnan Province (82.7 ± 0.7 Ma, muscovite 40 Ar-39 Ar age;Cheng, Mao, & Yang, 2012); the Yingwuling W-Sn polymetallic mineralization in western Guangdong Province (79-81 Ma, LA-ICPMS cassiterite and zircon age;Zheng, Mao, Zhao, Zhao, & Yu, 2017;Zhang et al, 2018); the Xishan Sn-W deposit in western Guangdong Province (79.4 ± 4.5 Ma, molybdenite Re-Os isochron age;; and the Yinyan Sn deposit in western Guangdong Province(78)(79)(80) …”

Geochemistry and chronology of the granites in Alasituo, west Tianshan Orogen: Implications for a magma mixing origin

“…The petrogenetic classification of intrusive rocks relies on the foundation of granitic research (Zheng, Mao, Zhao, Zhao, & Yu, 2017). A-type granites have been studied for a long time because of their unique geochemical characteristics and tectonic kinetic significance (Eby, 1990(Eby, , 1992Jia, Wang, & Tang, 2009;Wang, Jiao, Tong, & Yao, 2013;Whalen, Currie, & Chappell, 1987;Zhang, 2013;Zhang, Ran, & Li, 2012).…”

Petrogenesis of the Early Cretaceous Tiantangshan A-Type Granite, Cathaysia Block, SE China: Implication for the Tin Mineralization

“…They are enriched in Nb, Zr, Ce, Y and HFSEs with relatively high alkali contents [7,12]. Most can be further classified as A 2 type granite [13,14]. They have been interpreted as derived from the partial melting of Precambrian crustal rocks [15].…”