The Heijianshan Fe–Cu (–Au) (or IOCG-like) deposit underwent five alteration and mineralization stages: Pre-ore epidote alteration (Stage I), syn-ore magnetite/iron mineralization (Stage II) followed by pyrite alteration (Stage III) and Cu (–Au) mineralization (Stage IV), and post-ore late veins (Stage V). The Heijianshan orebodies are commonly hosted by tuff, the middle member of the Matoutan Formation, and they are mainly stratiform or tabular, with the largest one being 30–50 m long and 8–10 m wide in the open pit.

The orebodies are mainly tabular or stratiform and are hosted within the basaltic to andesitic tuff and breccia tuff in the middle section of the Tugutubulak Formation. Three types of ore, such as iron ore, sulfide ore, and mixed iron-sulfide ore, are identified in Heijianshan and they mostly occur as massive, disseminated, and brecciated (magnetite clastic breccia) structures.

The Heijianshan iron deposit, containing a reserve of 12.06 Mt Fe and 0.38 Mt Cu ore with an average grade of 43.32 wt.% and 0.78 wt.%, respectively. The strata exposed in the deposit are composed of Upper Carboniferous Tugutubulak Formation, which can be divided into three lithological Units from the bottom upwards. Unit 1 is exposed in the northern and eastern portions of the deposit, encompassing sedimentary tuff, regular tuff, and basalt; Unit 2 is identified in the central and western sectors of the deposit, consisting of andesitic tuff, brecciated tuff, brecciated andesite lava, and basalt; Unit 3 is exposed in the central and western sections of the deposit, comprising andesitic tuff lava. The Heijianshan iron deposit is situated within Unit 2 and Unit 3. The Heijianshan orebody is usually stratified with a length of 4.4 km and a width of 2.4 km. The maximum thickness of the orebody is 9.6 m.

Other Regions, Features and Areas containing this locality

References