Geochemical Characteristics And Tectonic Significance Of The Gudian Area In Northern Shanxi Province

The study area is located at the northern margin of the North China plate,in the eastern section of the Yinshan Mountain range at the junction of Jin,Ji and Mongolia provinces(regions)in northern Shanxi Province,with a general northeast-to-southwest trend,the north located at the southeastern margin of the Inner Mongolia fault block,and the south located at the eastern branch of the Datong Basin.The Precambrian metamorphic basement structure and Mesozoic-Cenozoic structure are widely developed in the area.Since the Archean,they have experienced multiple tectonic movements and formed complex geological conditions.The previous work in this area is mainly focused on prospecting using geochemical exploration,but the relationship between structure and the distribution and aggregation of elements is still inadequate.Therefore,this paper takes the geochemical characteristics and tectonic significance of Gudian area in northern Shanxi Province as the topic,Starting from1 : 5000 river sediment measurements,field surveys and previous geological data collection.The elemental geochemistry characteristics and deformation characteristics of Mesozoic-Cenozoic faulted structures in Gudian area are studied in detail,and the tectonic significance indicated by them is preliminarily discussed on the basis of in-depth analysis of geochemical integrated anomaly characteristics.The analysis results of 1 : 50000 river sediment samples in Gudian region show that Au,Ag,Pb,Zn,W and Mo are the main metallogenic elements in the study area.The variation coefficient of each major metallogenic element is basically greater than one,and the distribution is also extremely uneven.The maximum value and standard deviation of most elements are large,and higher than the background value of elements.According to the distribution characteristics of strata and magmatic rocks,the geological units in the study area are divided into thirteen,among which the neo-archean magmatic rocks and quaternary samples account for a large proportion,the geochemical characteristics of the elements in the region are mainly shown in neoarchean magmatic rocks and quaternary units.The geochemical integrated anomalies in the study area mainly include AS4,AS9,AS10,AS12,AS31 and AS36.The in-depth analysis of these six integrated abnormal characteristics and the study combined with the deformation characteristics of the faultedstructures in the area shows that the zoning and concentration of the element anomalies are mainly controlled by the NE-trending and NW-trending fault structures in the area,and a small part is controlled by the NS-trending faults.Among them,Au anomalies are obviously controlled by NW-trending faults,and most of the other ore-forming elements are distributed in NW direction.In particular,the distribution of Ag,Pb,W,Mo,Cd and Bi elements are especially controlled by NW-trending faults.At the intersection of fault structure cutting,the concentration of elements tends to be higher,and the abnormal range is larger,which is the most favorable position to find hidden ore bodies.