Geological Characteristics and Genesis of Songmuzhuang Iron Deposit ofEastern Hebei Province

The Precambrian banded iron formation (BIF) is the most important iron deposit type in the world. Eastern Hebei is one of the most important iron ore provinces in China. The Songmuzhuang iron deposit, located at Qian’an, is a large and typical BIF-type iron deposit. The Songmuzhuang iron ore is located in the north of Qian"an in Eastern Hebei Province. It is a large iron ore deposit and the most typical BIF iron ore in this area. The iron ore body occurs in the metamorphic rock strata of the second member of the santunying formation of the Qianxi group of the Archaean. The surrounding rock of the ore body is mainly migmatite and biotite hornblende plagiogneiss. The ore body is bedlike, and the occurrence is basically consistent with the surrounding rock. The ore structure is mainly granular and crystalloblastic structure, and the structure is mainly striped, banded and gneissic. The mineral composition is simple. The metal minerals are mainly magnetite and a small amount of false hematite. Gangue minerals are mainly quartz, perilla pyroxene and augite, with a small amount of amphibole, garnet, diopside and pyrite. Altered minerals include chlorite and calcite. The results of element combination analysis show that (CaO + MgO) / (SiO2 + Al2O3) = 0.12 < 0.5, and the ore belongs to acid ore. According to spectral analysis, the content of other elements in the ore is low. The ore minerals of the deposit are relatively simple. It is speculated that the songmuzhuang iron mine may be formed by the submarine volcanic eruption, carrying a large amount of siliceous iron, which is formed by sedimentation, and then enriched by regional metamorphism. The iron source during the formation of magnetite quartzite should be related to volcanic activities. To sum up, Muzhuang iron ore belongs to Anshan type sedimentary metamorphic iron ore.