| Jinsuoqiao iron gold deposit is located in the western margin of the Yangziplatform.It’s a long-term uplift zone,which Pre Sinian metamorphic rocks asbase,Paleozoic marine deposits as cover layer. Huidong region experiencedJinning period magmaticactivity and mineralization,which bringing rich iron,copper,gold and other minerals from the interior of the earth.Have a good ore-forminggeological conditions.Further study on the geological characteristics of thisdeposit,summarizes the prospecting marks,the prospecting direction,has the importanttheory significance and practical value.Through the field mapping of Jinsuoqiao,collecting a representativesample,combining microscopic observation,geochemical analysis and inclusionsexperimental work,mainly achieved the following understanding:The Qinglongshan formation of the Middle Proterozoic is the ore-bearingstrata,composed mainly of stalline limestone and Sericite phyllite.Hypabyssalbody(dyke),such as granodiorite diorite porphyry,granodiorite porphyry,quartzporphyry is closely associated with iron or gold ore body in space.often become theroof or floor.Interformational fracture zone and tectonic weak belts often the outputpart of ore body.The ore bodies are mainly iron ore and gold,copper mineralizationin the local. Iron(gold)ore body mainly showed vein and lens shape distribution,Hasa trait is lateral en echelon,there are predicting deep ore mine.Gold mineralizationlater than iron mineralization,in the broken ore body and side band or fracturedplace,with quartz vein/mass and output.Output with the quartz vein/mass.Metal mineral in the ore are mainly hematite and limonite,a small amount ofmagnetite,siderite, pyrite,chalcopyrite, trace native gold or electrum.Our analysis ofthe data showed that the iron ore grade (Fe+Mn) most40%to55%,phosphorus0.03%to0.35%(average0.10%),sulfur0.03%to0.62%(average0.14%),ore quality overallgood,SiO2content of10.43~19.04%, as the main harmful ingredients,gold grade3.1~7.4g/t, associated silver13~41g/t.This area is peraluminous calc-alkaline acidic rocks in high degree ofdifferences,with mantle-derived granite characteristics. Relatively enriched in LREE,poored in HREE,Eu no abnormalities,indicating that the iron ore without crystallization differentiation.PGE in iron ore is relatively low (Ir,Ru,Rh,Pt,Pd totalof:1×10-9to1.84×10-9),has a significant positive Ru anomaly (δRu=1.67to5.18),higher Pd/Ir (15.1to30),PGE strong fractionation has occurred,which may berelated to hydrothermal mineralization.Deposit formed in Jinningian,rockLA-ICP-MS zircon U-Pb age of1455±38Ma.Quartz veins containing ore bodyinclusions study showed that the ore-forming fluid is medium-low(130℃to240℃),mean salinity is19.13wt%,mean density is1.18g/cm3.The gold mine concentrated in the center of hydrothermal activity,gold (orcopper) can be distributed in the periphery or the lower of the iron ore body,gold isoften superimposed on iron ore and constitutes gold-iron mineralization. Shallowrock, limonite, tectonic fracture zones and layers broken belt,old undergroundworkings and tunnels are prospecting criteria for gold-iron ore.Contact zones betweensurrounding rock and granodiorite diorite porphyry,granodiorite diorite porphyry,deepmining has been proven and the periphery of limonite ore belts and interlayer fracturezones in mining area can be the next step in the direction of prospecting.The miningareas in central of lower elevation,such as Shuangnongchang,Maosi andShengziyan,can be used as gold ore prospecting target area;In the peripheral miningarea of high elevation,such as Yewan,Caizid,can bbe used as iron ore region; In theperipheral mining area,such as the north of Laocunzi are founded copper vein,can beused as a copper ore prospective area. |
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