ZHAO Ze-nan1, WANG Yin-hong1, WANG Jian-ping1, DONG Li-shuai2, WANG Hong2, ZHANG Fang-fang1, LIU Bin1
(1. China University of Geosciences, Beijing 100083, China;
2 . No.11 Geological Party of Hebei Bureau of Geology and Mineral Resources, Xingtai 054000, China)
Abstract：The Tuwu copper deposit is located in the middle of the Late Paleozoic Dananhu island arc, and the main part of the ore bodies occurred in diorite porphyrite. The diorite porphyrite belongs to sodium sub-alkaline series, and has the following compositional ranges: SiO2 (51.56%－56.98%), Al2O3 (16.41%－19.17%), Na2O (2.6%－5.42%), K2O (0.582%－2.24%) and full alkali (Na2O+K2O) (3.182%－6.205%), with K2O/Na2O ratios ranging from 0.144 to 0.78). The spider diagram has a curve inclined to the right representing LILE enrichment, HREE depletion, and negative Nb and Ta anomalies. The ΣREE contents range from 50.64×10-6 to 117.73×10-6, and LREE/HREE ratios range from 3.40 to 5.98. The δEu values vary from 0.65 to 1.10. These characteristics indicate that there is no obvious plagioclase crystal fractionation. The δCe values, ranging from 0.90 to 0.99, show that oxidizing conditions are weak. The geochemistry and geochronology of the diorite porphyrite, combined with the tectonic environment, indicate that the diorite porphyrite was formed in the active continental margin of the Kazakhstan-Junggar plate.
Key words: porphyry copper deposit; diorite porphyrite; geochemistry; U-Pb zircon age; geological significance; Tuwu copper deposit
ACTA MINERALOGICA SINICA Vol. 34, No. 4, 2014, Page 512-520
