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Recent exploration has led to definition of a Middle–Late Jurassic copper belt with an extent of ~2000 km along the southeast China coast. The 171–153 Ma magmatic-hydrothermal copper systems consist of porphyry, skarn, and vein-style deposits. These systems developed along several northeast-trending transpressive fault zones formed at the margins of Jurassic volcanic basins, although the world-class 171 Ma Dexing porphyry copper system was controlled by a major reactivated Neoproterozoic suture zone in the South China block. The southeast China coastal porphyry belt is parallel to the northeast-trending, temporally overlapping, 165–150 Ma tin-tungsten province, which developed in the Nanling region in a back-arc transtensional setting several hundred kilometers inboard. A new geodynamic-metallogenic model linking the two parallel belts is proposed, which is similar to that characterizing the Cenozoic metallogenic evolution of the Central Andes.

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.

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