Abstract:
The Gangli region in Fujian is located in the northern section of the Changle-Nan’ao fault zone, with the Gangli metamorphic rocks in the southeastern side of the Changle-Nanao fault zone and the volcanic rocks of the Nanyuan Formation in its northwestern side. The study conducted comparative analysis on geochemical features and zircon U-Pb ages of the Gangli metamorphic rocks and the Nanyuan Fm. volcanic rocks. The results show that the zircons from both the Gangli metamorphic rocks and the Nanyuan Fm. volcanic rock have concordant ages of 139.7±1.8 Ma and 132.7±1.2 Ma, respectively, suggesting the both are early Cretaceous in age. The both belong to cal-alkaline series, characterized by high SiO
2, low Ba, Nb, Sr, and high Pb and Nd, and low total REE content, enrichment in LREE, and medium Eu depletion in REE distribution diagram. This reflects the geochemical features of the middle Cretaceous volcanic rocks on both side of the fault zone.