Geological characteristics and genesis of the iron deposits in the Taxkorgan area, west Kunlun

The Taxkorgan area located in west of Kunlun and Arkin metallogenic belt, it hosts a few iron deposits with Fe reserves up to large scale, such as the Zankan, Mokaer, Laobing and Ylike iron deposits. The discovery of these deposits is one of the major breakthroughs in ore exploration in the area and of great academic significance. The main strata in the Taxkorgan district are biotite quartz schist and biotite plagioclase gneiss of Paleoproterozoic Bulunkuole Group. Magnetite ore bodies are layered or layer-like. The metallic minerals are magnetite and pyrite and the main gangue minerals are anhydrite (gypsum), biotite, chlorite and quartz. The ores are characterized by magnetite-anhydrite-pyrite assemblage. The ore textures include euhedral-subhedral granular texture, anhedral granular texture, metasomatic pseudomorphic texture. The formation of the Taxkorgan iron deposits can be divided into four stages: initial sedimentary stage, regional metamorphic stage, hydrothermal transformation stage and supergene oxidation stage. The preliminary study showed that most of the magnetite and anhydrite (gypsum) formed in the initial sedimentary stage. Most of the pyrite may be the result of post-hydrothermal reaction with anhydrite (gypsum). It can be concluded that the magnetite deposits in the Taxkorgan area were closely related to submarine volcanic hydrothermal sedimentary-metamorphic processes, however, there were a lot of terrigenous clastic participated in the forming processes, which is clearly different to the typical BIF type.