Genetic Types and Metallogenic Model for the Polymetallic Copper–Gold Deposits in the Tongling Ore District, Anhui Province, Eastern China

The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurrences. Those deposits are mainly clustered(from west to east) within the Tongguanshan, Shizishan, Xinqiao, Fenghuangshan, and Shatanjiao orefields. Until recently, the majority of these deposits were thought to be skarn-or porphyry–skarn-type deposits; however there have been recent discoveries of numerous vein-type Au, Ag, and Pb-Zn deposits that do not fall into either of these categories. This indicates that there is some uncertainty over this classification. Here, we present the results of several systematic geological studies of representative deposits in the Tongling ore district. From investigation of the ore-controlling structures, lithology of the host rock, mineral assemblages, and the characteristics of the mineralization and alteration within these deposits, three genetic types of deposits(skarn-, porphyry-, and vein-type deposits) have been identified. The spatial and temporal relationships between the orebodies and Yanshanian intrusions combined with the sources of the ore-forming fluids and metals, as well as the geodynamic setting of this ore district, indicate that all three deposit types are genetically related each other and constitute a magmatic–hydrothermal system. This study outlines a model that relates the polymetallic copper–gold porphyry-, skarn-, and vein-type deposits within the Tongling ore district. This model provides a theoretical basis to guide exploration for deep-seated and concealed porphyry-type Cu(–Mo, –Au) deposits as well as shallow vein-type Au, Ag, and Pb–Zn deposits in this area and elsewhere.

DIWA TYPE OF GOLD MINERALIZATION IN THE YINSHAN-YANSHAN-LIAO-JI ORE BELT,CHINA

DIWA TYPE OF GOLD MINERALIZATIONIN THE YINSHAN-YANSHAN-LIAO-JIORE BELT, CHINAWang Fuquan(Changsha Institute of Geotectonics, Academia Sinica, Changsha, 410013, Hunan, China)Yinshan-Yanshan-Liao-Ji gold ore belt diwa type of gold mineralization, diwa regime, diwa type oftectono-magmatismThis studied gold ore belt is giant and very important in China. Its regional tectonics and evolutional process are complicated. There are a few of view points on its geotec-tonic attribute in the Mesozoic and Cenozoic eras and on the type of its some gold ore deposits, especially, on one hosted in the pre-diwa geological bodies. On the basis of the diwa theory, the author discussed the regionalization, and its evolutional process, and some features of diwa tectono-magmatism and diwa type of gold mineralization in this belt. The author proposed that(1)the main body zone is a part of the diwa regime in the Mesozoic and Cenozoic eras, and(2)the diwa tectono-magmatism had a series of features such as

Minerogenetic mechanism of Rushan gold deposit, Shandong Province——Evidence of ore-forming fluid and H, O, Sr isotopes

THE Rushan gold deposit, being of quartz-vein type, is located in biotite monzonitic granite of Kunyushan complex pluton in eastern Shandong, China, and the orebody No. 2 is the largest mono-vein deposits found in China. The gold mineralization can be divided into three stages according to crisscross relations of the various microlodes in the deposit: Ⅰ. pre-ore stage of comb-structured milky-white quartz veins; Ⅱ. main mineralization stage of multi-metal sulphides and siderite-quartz veins; Ⅲ. post-ore stage of mottled cryptocrystalline quartz veins.