Haobugao Cu-polymetallic deposit, Bairin Left Banner (Balin Zuoqi), Chifeng City (Ulanhad League; Chifeng Prefecture), Inner Mongolia, Chinai

Regional Level Types
Haobugao Cu-polymetallic deposit	Deposit
Bairin Left Banner (Balin Zuoqi)	County
Chifeng City (Ulanhad League; Chifeng Prefecture)	Prefecture-level City
Inner Mongolia	Autonomous Region
China	Country

Large-sized polymetallic skarn deposit, located in the northwestern limb of the northern part of the Huanggang-Ganzhuermiao anticlinorium. The ore bodies occur in the contact zone between the Haobugao granitic intrusive and rocks of the early Permian Dashizhai Formation. The main controlling structures for the deposit and the granitic intrusive are NE-striking fracture zones. There are three episodes of late Yanshannian igneous intrusions: (1) a first stage of porphyroid biotite-amphibole adamellite (Xiaohanshan granite); (2) a second stage of biotite moyite (Wulanba and Wulanchulute granite); and (3) a third stage of granite porphyry (Haobugao granite). Wallrock alteration is dominated by skarn. Locally, silica, beresite, epidote, and chlorite alterations occur.

The estimated Zn resource is 0.36 million tonnes (@ 4.00 wt% Zn). There are 7.72 million tonnes of Fe ore, with an average grade of 32.41 wt% Fe. Sn mineralization occurred in this deposit, but no grade data were reported. In addition, this deposit contains 15,766 tonnes of Cu (0.90 wt%) and 6760 tonnes of Pb (1.73 wt%). The wallrocks of the mining district include the lower Permian Dashizhai Formation and the Upper Jurassic Manketou Ebo Formation. The lower part of the Dashizhai Formation is composed of siltstone and shale with limestone interlayers that are partly metamorphosed to hornfels, slate, and marble; the upper part includes andesite and andesitic tuff. The rhyolitic pyroclastic rocks of the Manketou Ebo Formation unconformably overlie those of the Dashizhai Formation. The Haobugao orebodies are spatially zoned (Fig. 1c). From northeast to southwest, the orebodies change from Fe–Sn (orebody I) to Cu–Zn (orebody II), Zn–Ag (orebody III), Pb–Ag (orebody IV), and Pb–Zn–Cu (orebody V). There is a high garnet/pyroxene ratio and Fe-Cu-Mo mineralization at depth near the biotite granite, whereas pyroxene and wollastonite are the main skarn minerals, and Pb–Zn mineralization developed upward. Five skarn mineralization stages are recognized: (1) the early skarn stage, (2) the late skarn stage, (3) the oxide stage, (4) the quartz-sulfide stage, and (5) the calcite stage.

Other Regions, Features and Areas containing this locality

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