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Geochemistry of Pyrite from the Gangcha Gold Deposit, West Qinling Orogen, China: Implications for Ore Genesis
Author(s) -
NIE Xiao,
SHEN Junfeng,
LIU Haiming,
DU Baisong,
WANG Shuhao,
LI Jie,
XU Liwei,
WANG Ran
Publication year - 2017
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.13456
Subject(s) - pyrite , geology , electron microprobe , geochemistry , trace element , mineral , electron probe microanalysis , ore genesis , mineralogy , isotope geochemistry , fluid inclusions , isotope , quartz , metallurgy , materials science , paleontology , physics , quantum mechanics
The Gangcha gold deposit was discovered in 2011 in the Xiahe‐Hezuo region, West Qinling Orogen, China. Five types of pyrite have been identified in the ore according to the detailed mineral paragenetic studies. Geochemical data are presented for type I pyrite (py1) rim‐core zonation and for the different types of pyrite based on in‐situ laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) and electron probe microanalysis (EPMA). The results show that pyrites are characterized with heterogeneous Au concentrations, which indicate that Au occurs mainly as micro‐ or nano‐particle native inclusions. Time‐resolved depth profiles demonstrate that As, Co and Ni occur as solid solutions in pyrite, whereas Cu, Pb, Zn and Ag occur mainly as inclusions. Trace element concentrations differ between rims and cores in py1, and the differences also exist within different pyrite types. These differences indicate complex chemical evolution of the ore‐forming fluids, and the overall geology, geochronology, and stable isotope and pyrite data suggest that the ore‐forming fluids were closely linked to magmatic activity during the Triassic Period in West Qinling orogenic belt.