Large-scale iron deposit, consisting of several layers in host metamorphic rock of the Archean Anshan Group occurring in an anticlinorium that was intruded and reworked during two periods of granite plutonism at about 2,100 to 2,300 Ma, and 1,700 to 1,900 Ma. Host metamorphic rocks ared biotite microgneiss, amphibolite, micaschist, biotite gneiss, and garnet-chlorite schist that are derived from volcanic and sedimentary units. There are one to eight deposit beds, and individual deposit beds range from several meters to several tens of meters thick, and from several hundred meters to 1 km long. Textures in the deposit layers are banded, paragneissic, and massive, and the ore minerals are coarse-grained magnetite, quartz and minor amphibole. Moderate amounts of rich ores, with over 50% Fe consist mainly of magnetite, maghemite, graphite, quartz, garnet, cummingtonite, pyrite, and pyrrhotite with mainly massive textures and local porous textures.
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http://pubs.usgs.gov/of/2004/1252/metallog_belt_map/metbelt_descript.doc11 entries listed. 7 valid minerals.
