Abstract:

Jiande copper deposit in Zhejiang Province was found in the 1960, and it is located in the northeastern part of
Qinzhou-Hangzhou suture belt between Yangtze and Cathaysia blocks. Research about ore-forming fluids on it is still lacking. This
study made a systematic investigation of fluid inclusions in the Jiande copper deposit. Based on petrographic observations of
ore-bearing quartz collected from the massive ores, there are three types of primary inclusions of Jiande deposit: two-phase liquid-rich
(type I), two-phase vapor-rich (type II), and halite-bearing (type III) fluid inclusions. Type I inclusions occur widely in the Jiande

deposit and show homogenization temperatures of 220~377℃ and salinities of 0.63~8.00 wt.%NaCl equivalent. Type II and type III
inclusions primarily coexist in ore veins. Homogenization temperatures of type II and type III reveal peak temperatures at 296~334℃
and 290~326℃ , respectively, and their salinities at 1.22~2.00 wt.% NaCl and 31.87~38.16 wt.% NaCl, respectively. The results
indicate that fluid boiling process took place, and metal precipitation was probably induced by extensive fluid boiling events during the
ore stage. Raman analysis of fluid inclusions indicates that, in the gaseous phase, water is dominant with small amount of CO2, CH4, and
N2. Our study suggests that the Jiangde copper deposit is a Yanshanian Skarn deposit rather than a Hycernian Sedex Cu deposit.

Key words: fluid inclusion, microthermometry, raman spectroscopy, jiande copper deposit, Zhejiang Province