Geochemical Features And Ore Prediction Of Stream Sediment Survey In Bamian Area,Fujian Province

The paper is extended by the research of “ Investigation of Au-Cu-polymetallic factors in Suichang,Zhejiang-Shanghang,Fujian Area(No.DD20160037)” and national key project “3D integrated detection and deep mineralization prediction in Dehua,Wuyi-Yongtai,Youxi mineral concentrated area(No.2016YFC0600210)” in the 13 th Five-Year Period.With the summary and in-depth analysis of previous data,main outcomes and knowledge are obtained by systematic study of regional geology,petrology and geochemistry in Banmian area,Fujian Province.And the results are listed as follows:(1)Pb,Cd,W and Mo are rich and unevenly distributed in study area,which is related to magmatic hydrothermal events,having high metallogenetic potential.Ni,Cr,Co,Cu and Mn are relatively poor,which is related to less basic magmatic activities.Au is enriched in the particular layer,which has metallogenetic potential to some extent.(2)Cr,Mn,Co,Ni,Cu,W,Au are enriched and unevenly distributed in Presinian strata,relating to intermediate-basic rocks contained in this strata and its Au-bearing features,which is a important ore forming layer in the study area.Pb,Zn,Cd are most enriched in Lower Permian Strata,relating to the Pb-Zn Ore in it.Ba is most enriched in Silurian rock mass,caused by its high background value.Mo is most enriched in Cretaceous rock mass and has the potential of Mo mineralization.(3)Combining R type clustering analysis and factorial analysis with geological background in study area,12 elements are divided into three groups to evaluate anomaly assemblage.Mn,Cr,Ni,Cu and Co are chalcophile or siderophile elements,and their anomaly are mainly distributed in Presinian,lower Permian and upper Jurassic in the southwest of the map,which is significant for Fe,Cu ore prospecting.Au,W,Mo compose a set of magmatic-hydrothermal metallogenic elements,mainly controlled by Presinian strata and small rock mass,which is significant for Au,W,Mo ore prospecting.Pb,Zn,Cd make up a set of epithermal metallogenic elements,and their anomalies are mainly distributed in the Presinian,lower Permian and upper Jurassic in the southwest of the map,which is significant to Pb and Zn ore prospecting.(4)Seven anomalies are marked out.Two of them are Class A anomaly and the rest five are Class B anomaly.Evaluation and interpretation are made respectively to give specific suggestions for the next step of the project.Among them,HS-3-Class A1,HS-7-Class A1 have good potential of ore prospecting.On the basis listed above,ore prospective areas are divided into two,one is class I,the other is Class II,pointing out the direction of ore prospecting.It was found that Cu and W accompany Pb-Zn Ores in study area,enhancing the economic value of this kinds of ores.Combined anomalies with geological characteristics,this kind of deposits are considered as magmatic hydrothermal deposits,closely related to intrusive bodies.Great care should be put in next-step work,especially for the less studied small rock mass.Au and Fe are obviously strata-bound,so Presinian is the main target in mineral exploration.