Zircon U-Pb age of the Lufengshan miarolitic granite inFujian Province and its geological significance

In comparison with the contemporary granite in eastern Taiwan, this paper analyzed the characteristics of tectonic and magmatic activities and tectonic environment of Fujian and Taiwan during late Mesozoic using petrography and zircon U-Pb isotope ages of Lufengshan miarolitic granite. Main rock type at Lufengshan is medium to fine-grained miarolitic alkali feldspar granite, which belongs to A-type granite with the characteristic miarolitic texture. LA-ICP-MS zircon U-Pb dating yielded three ages of 84.5±1.0 Ma, 81.8±0.6 Ma and 84.9±0.5 Ma for the Lufengshan miarolitic granite. Combined with the ages of other miarolitic granites in the area, it can be concluded that the miarolitic granites in the southeastern part of the Changle-Nan’ao fault zone formed at 93.8～81.8 Ma, belonging to late Cretaceous. The magmatic activity moved eastward, which might have been controlled by subduction retrogression of the paleo-Pacific Plate. Therefore, this tectonic-magmatic activity and felsic magmatism in eastern Taiwan should belong to the same tectonic-magmatic event.