Jinxiantou Au–Cu deposit, Qibaoshan polymetallic ore field, Wulian Co., Rizhao, Shandong, Chinai

Regional Level Types
Jinxiantou Au–Cu deposit	Deposit
Qibaoshan polymetallic ore field	Ore Field
Wulian Co.	County
Rizhao	Prefecture-level City
Shandong	Province
China	Country

Southern part of the Qibaoshan subvolcanic complex where the ore body is mainly controlled by a breccia pipe. The breccia pipe is elliptical in plan, with a NW-SE trend, plunge 68-70° SE, about 400 m long, 120–300 m wide and 600 m deep. Based on the cross-cutting relationships of the veins and the sequence of mineral formation, the formation of the deposit can be divided into a quartz-pyrite stage, a gold-bearing quartz-siderite- hematite stage, a gold-pyrite-chalcopyrite-quartz-carbonate stage, and a late quartz-carbonate stage.

The exposed strata predominantly consist of the Bamudi and Fanggezhuang Formations, which are of the Cretaceous period. Mesozoic sub-volcanic complexes are extensively developed in the Cu-Au deposit, predominantly composed of pyroxene diorite, quartz diorite porphyry and andesite porphyry. These igneous rocks are important host rocks, with the Cretaceous quartz diorite porphyry exhibiting particularly close genetic relationships with Cu-Au mineralization.
The Jinxiantou Cu-Au deposit, containing 10.96 Mt of Cu reserves with an average grade of 0.58 % Cu, is a medium-scale Cu deposit in the ore district and is mainly characterized by crypto-explosive breccia Cu-Au mineralization and irregular cylindrical orebodies in space. The deposit also hosts substantial Au resources, with an average Au grade of 4.97 g/t and proven Au reserves of 1,422 kg. The Jinxiantou Cu-Au deposit comprises 134 individual orebodies, which can be classified into 5 groups based on spatial–temporal relationships. Among these, the main orebody in the southeastern part of Jinxiantou contains the majority of the reserves and has the highest economic value. Au mineralization dominates at shallow levels, whereas Cu mineralization dominates at greater depth, displaying a clear vertical metal zonation. The open-pit primarily hosts two types of orebodies: (1) veinlet-disseminated type pyrite vein, and (2) crypto-explosive breccia type Cu-Au orebodies. The Jinxiantou Cu-Au deposit displays distinct spatial zonation of alteration assemblages.

Other Regions, Features and Areas containing this locality

References