2.1. Sedimentary - metamorphic iron ore deposits

This type of iron deposits is also called banded iron formation (BIF). The mineralization ages were mainly Archean and Paleoproterozoic. The reserves of proven mineral resources were probably more than 33 billion tons, accounting for 55% of the total reserves of the country, which is a very important iron ore in China. According to the ore and gouge mineral association, as well as geological features, it would be subdivided into metamorphic iron-siliceous iron ore deposits and metamorphic carbonate iron ore deposits. Their grades were about 25– 40% (w(TFe)).

The BIF were affected by regional metamorphism and associated with volcanic-iron-siliceous sedimentary deposits. They mainly developed in the Precambrian metamorphic rocks, mostly large deposits. The Anshan in Liaoning Province, Jidong in Hebei Province, Wutai-Lvliang in Shanxi Province, and central Inner Mongolia are mainly developed area where the iron ore deposits were thought the most representative. The southern margin of Yangtze plate, Qinling orogenic belt, Qilian orogenic belt, and the East Tianshan region were also distributed.

The metamorphic carbonate iron deposits were carbonate-type sedimentary iron deposits suffered to minor regional metamorphism. They mainly developed in the Proterozoic strata, and the southeast Jilin Province is known for yielding this deposit. That led to it also called "Dalizi type iron ore deposit" in China, although it is also developed in Yimen, Eshan, Huanian in Yunnan Province.

#### 2.2. Late magmatic iron ore deposits

This type of iron ore deposit is associated with the mafic-ultramafic magmatic intrusions of the iron and its iron minerals are rich in vanadium and titanium, commonly referred to as vanadium-titanium magnetite deposits. The mineralization ages are mainly Paleozoic and Proterozoic, with proven reserves of 9 billion tons, accounting for 15% of the total reserves of the country. According to the metallogensis, they can be subdivided into late magmatic differentiated deposits and late magmatic intrusive iron deposits. Late magmatic differentiated iron deposits are formed by the residual magma rich in iron, vanadium and titanium formed by late differentiation of magma crystals. These deposits are mostly of large in reserve and are mainly distributed in Panzhihua and Xichang area in Sichuan Province. They are often called "Panzhihua-type" iron deposits in China. Late magmatic intrusive iron deposits are latedifferentiated iron-bearing ore fluids that break into or along the rock mass. The reserve of this type deposit is generally medium to small, mainly distributed in the Damiao and Heishan in Hebei Province, which is called the "Damiao-type" iron deposit.
