Jh. Yang et Xh. Zhou, Rb-Sr, Sm-Nd, and Pb isotope systematics of pyrite: Implications for the age and genesis of lode gold deposits, GEOLOGY, 29(8), 2001, pp. 711-714
Lode gold deposits commonly consist of pyrite and lesser amounts of lead an
d zinc sulfides accompanied by quartz and calcite. Their exact origin remai
ns controversial mainly because of the scarcity of reliable geochronologica
l data. Here we present direct Rb-Sr dating of pyrite from a lode gold depo
sit and propose the method as a useful geochronological technique for gold
mineralization for which age data are poor. A positive correlation between
present-day Sr-87/Sr-86 and Rb-87/Sr-86 ratios of pyrite (FeS2) subsamples
from the Linglong gold mine of China corresponds to an age of 122-123 Ma, w
hich dates the age of gold mineralization. The Sr, Nd, and Ph isotopic comp
ositions of pyrites and the associated rocks suggest that the hydrothermal
fluids responsible for the pyrite and gold mineralization were probably der
ived from a mixed source (i.e., degassing of mafic magmas and meteoric wate
r that had leached the country rocks).