Jinchang Au deposit (Jingchang Au deposit), Dongning County, Mudanjiang, Heilongjiang, Chinai

Regional Level Types
Jinchang Au deposit (Jingchang Au deposit)	Deposit
Dongning County	County
Mudanjiang	Prefecture
Heilongjiang	Province
China	Country

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Vein and breccia type gold mineralization, associated with a porphyry intrusion.
Diorite, graphic granite, and granite are widely exposed within the Jinchang Deposit and yield U–Pb ages of 209–185 Ma, indicating that they were emplaced after collision of the North China Craton and the Jiamusi–Xingkai Block. These rocks are the main hosts of the ore body and are extensively altered adjacent to the mineralization. The granodiorite, diorite porphyry, and granite porphyry yield U–Pb ages of 118–106 Ma, indicating that these rocks were emplaced during subduction of the Pacific Plate beneath the Eurasian Plate. Several diorite porphyry and granite porphyry dikes are crosscut by the ore body and are therefore interpreted to have formed prior to mineralization. Granodiorite is widespread, was emplaced in the deepest parts of the area (J11, J14, J17, and No. 18 orebodies), is extensively altered, and contains disseminated pyrite, suggesting a causal link between granodiorite emplacement and mineralization.

Jinchang is a large-scale porphyry Au-copper deposit, with 80 tons of Au and 4683 tons of copper. Twenty-three orebodies have been discovered. According to the occurrence and characteristics of ore bodies, they can be divided into breccia ore (such as J0, J1, J2, etc.); fracture-controlled ore (such as No.Ⅱ, No.Ⅲ, No.X, etc.) and veinlet disseminated ore (such as No.18). These three orebody types contribute 41%, 39% and 20% of the Au, respectively. The Re-Os age of molybdenite in J0 is 113 ± 1 Ma and pyrite in J1 is 114 ± 22 Ma. Copper mineralization mainly occurs in the J0 breccia orebody. J0 is a typical breccia orebody with Au-Cu mineralization, in which the average Au grade is 11.34 g/t and the average copper grade is 1.44%. The ore body is located at the intersection of NW-SE and E-W trending faults, which mainly occur in the contact zone between the Late Triassic diorite and the Early Jurassic monzogranite, and ore extends downward to Early Cretaceous diorite porphyrite. The J0 orebody presents an irregular pipe-like shape with its long axis facing northeast-southwest (15°), but it is a long cylinder inclined 80–85° eastward in real three-dimensional space.

The Jinchang deposit exhibits a complex mineralization style, encompassing crypto-explosive breccia pipe-hosted, disseminated, and vein-type mineralization. The Triassic Luoquanzhan Formation consists primarily of dacitic to rhyolitic lavas and tuffs (217–208 Ma), overlain by Quaternary sediments.


Note: "Jingchang" is a mis-nomer.

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

Mineral List

38 valid minerals.

Rock Types Recorded