Ore-Fluid Evolution of the Sizhuang Orogenic Gold Deposit, Jiaodong Peninsula, China

Abstract

The Sizhuang gold deposit with a proven gold resource of >120 t, located in northwest Jiaodong Peninsula in China, lies in the southern part of the Jiaojia gold belt. Gold mineralization can be divided into altered rock type, auriferous quartz vein type, and sulfide-quartz veinlet in K-feldspar altered granite. According to mineral paragenesis and mineral crosscutting relationships, three stages of metal mineralization can be identified: early stage, main stage, and late stage. Gold mainly occurs in the main stage. The petrography and microthermometry of fluid inclusion shows three types of inclusions (type 1 H2O–CO2 inclusions, type 2 aqueous inclusions, and type 3 CO2 inclusions). Early stage quartz-hosted inclusions have a trapped temperatures range 303–390 °C. The gold-rich main stage contains a fluid-inclusion cluster with both type 1 and 2 inclusions (trapped between 279 and 298 °C), and a wide range of homogenization temperatures of CO2 occurs to the vapor phase (17.6 to 30.5 °C). The late stage calcite only contains type 1 inclusions with homogenization temperatures between 195 and 289 °C. With evidences from the H–O isotope data and the study of water–rock interaction, the metamorphic water of the Jiaodong Group is considered to be the dominating source for the ore-forming fluid. The ore-fluid belonged to a CO2–H2O–NaCl system with medium-low temperature (160–360 °C), medium-low salinity (3.00–11.83 wt% NaCl eq.), and low density (1.51–1.02 g/cm3). Fluid immiscibility caused by pressure fluctuation is the key mechanism in inducing gold mineralization in the Sizhuang gold deposit.

Fluid Inclusion Study of the Penjom, Tersang, and Selinsing Orogenic Gold Deposits, Peninsular Malaysia

“…The interpretation of metamorphic source is to be taken with caution as elevated CO 2 contents are not exclusively diagnostic of metamorphic origin of ore-forming fluids. Sizhuang, orogenic gold deposit, Jiaodong Peninsular in China [13] in which homogenisation temperatures range from 160 to 360 °C and salinity varies between 3.00 and 11.83 wt % NaCl equiv. The interpretation of metamorphic source is to be taken with caution as elevated CO2 contents are not exclusively diagnostic of metamorphic origin of ore-forming fluids.…”

A Geological-Geophysical Prospecting Model for Deep-Seated Gold Deposits in the Jiaodong Peninsula, China

“…Among them, geological methods mainly serve to delineate ore-prospecting target areas or directly discover orebodies according to ore-bearing regularity and prospecting indicators. Based on a large number of studies on gold mineralization [23][24][25][26][27][28][29][30][31][32][33][34], the main ore-bearing regularity and prospecting indicators are proposed as follows: the ore-bearing regularity of faults; the altered mineral indicators characterized by pyrite sericites and quartz veins; the equal-distance distribution laws of deposits; the laws of deposit paragenesis and ore deposit type zoning; and the pitch, pinch-out, and reappearance and arrangement laws of the orebodies.…”

40Ar–39Ar geochronology and palaeostress analysis using lamprophyre dikes and quartz veins in the Sizhuang gold deposit: new implications for Early Cretaceous stress regime in the Jiaodong Peninsula, North China Craton

“…The mine is established on the Linglong granite (Fig. 2b), which was replete with many irregular and discontinuous lamprophyre dikes, and a great number of quartz veins (Wei et al 2019; Fig. 2c).…”