The Structural Deformation And Metallogenic Prediction Of Banshigou Iron Ore Of Baishan City, Jiiin Province

Banshigou iron ore, located in the east section of the north margin of the North ChinaPlatform, the south wing of the Longgang duplex anticline, is typical Archeanmetamorphic complex exposed area in China. Banshigou iron ore suffered intensemetamorphism and deformation. This area is abundant in mineral resources. The iron oremainly is Anshan type iron ore. Large and medium-sized iron ore are mainly distributed inthe Archean Yangjiadian formation. Banshigou region is the favorable area of Anshan typeiron ore output. Studying on iron ore metallogenic prediction in the Banshigou region, hascertain significance for exploration deployment of iron ore.Based on the field research and analysis in the lab, this thesis has made thoroughresearch to the iron ores and surrounding rocks in the geochemical, geochronology andstructural ore-control characteristics. And main inclusions are as follows:The iron ore mainly is magnetite quartzite, secondly for amphibolite magnetite quartzite.The surrounding rocks of Banshigou iron ore are amphibolite, hornblende schist, bearingbiotite plagioclase gneiss. The magnetite quartzite and amphibolite rock are closelyassociated. Magnetite quartzite showed unequal thickness of lenticular and banding,intermittent distribution in the amphibolite rocks. The average content of silicon and ironoxide reached92.97%, and the REE distribution curve is consistent with Anshan-Benximagnetite quartzite, showing significant positive Eu and Y abnormal. The magnetitequartzite is result of seawater and hydrothermal fluid mixing chemical deposits.Banshigou iron ore occurrence in Archean Eon Yangjiadian formation, strictlycontrolled by the horizon. The original rock of formation rock is medium acid-basicvolcanic rock. The iron ore is magnetite quartzite containing higher iron, which has thecharacteristics of metamorphic rocks. The strong negative anomalies of high field strengthelements Nb, Zr, Hf and Ti, shows its mineralization relates to the volcanic action. The zircon LA-ICP-MS U-Pb age of amphibolite weighted average, which closelyassociated with Banshigou iron ore, is2548±11Ma, representing the formation age ofBanshigou iron ore. It is consistent with the age of Anshan iron ore.There are5mining areas and16ore formations in the Banshigou area. The orebody ofsouthern16,17and19ore formations north dipping, and northern7-8,14-15,6and othersore formations south dipping. These ore formations form the axial mine northwest ofduplex synform structure, which the turning point in Mutonggou area. The8ore formationorebody is duplex “syncline” fold plunging to SWW, composed by a series of sub-levelanticline and syncline structure. The Mutonggou orebody is NE trending, SE dipping, dipbetween10°~45°. The Mutonggou region has two ore-bearing strata, one is thin, and theother occurs fold deformation, resulting in local multilayer orebody of illusion.The iron ore and surrounding rock experienced three stage deformation metamorohism:the first phase is the early bedding extensional glide deformation, and this deformationmakes the Mutonggou orebody becaming the wider bedding glide fold. The second phaseis based in the first phase deformation surface, subjected the nearly N-S-trending extrusion,forming the nearly E-W-trending clement Banshigou duplex syncline, which is the mainstructure of Banshigou. The third phase is based in the second phase main tectonic outline,partial subjected NW-SE-trending extrusion, the second structure surface partial deformed,the local part of the orebody is transtormed into nearly S-N-trending.Banshigou iron occurrences in the core of fold tectonic. The ore body is thickness in thecore, and thinner or none in the wing. According to the festures of tectonic deformationand aeromagnetic anomaly, we select the lower part of8ore formation, the northeast ofMutonggou and the south and noutheast of17ore formation as the important mineralexploration prospect.The future prospecting direction: the core of fole deformation structure; looking for theblind orebody in the low and even magnetic anomaly area of the aeromagnetic anomalycoincide with the synclinal structure.