Characteristics And Structural Interpretation Of Magnetic Anomalies In The Shallow Sea Area Of The Northeast Of San Shan Island

China has become the world's first gold producer and gold consumer nation for many years,and its consumption is far greater than gold production.Therefore,it is important to increase gold production.Jiaodong Laizhou region is rich in gold resources,which is closely related to the fault structure and magmatic activities in Jiaozhou region.At present,China's gold exploration technology for land has been quite mature,but in recent years,land-openable mining deposits have been decreasing.China has turned its exploration direction to the sea and used high-precision magnetic survey data to find the distribution of fault zones.The First Institute of Oceanography of the State Oceanic Administration carried out magnetic surveying work in the shallow waters off the northeast of Sanshan Island.The purpose is to identify possible anomalies that may reveal deep faults in strata or upper bedrocks in the shallow waters of the northeastern Sanshan Island,such as shallow faults,sedimentary uplift or depression anomalies,and magnetic anomalies.It is necessary to conduct surveys of high-precision magnetic surveys in shallow sea areas to synthesize The various anomalies that may be caused by deep fractures and their occurrence characteristics are evaluated in the site area.The purpose of this paper is to use high-precision magnetic measurement data to infer the distribution of fault zones in the shallow waters of northeastern Sanshan Island and provide geophysical evidence for later exploration.Based on the magnetic data of the study area,this paper carries out work such as data inversion,polarization,extension,and so on,and on this basis,carries out data interpretation to partition the Sanshan Island sea area.Combining seismic profile data analysis and inferring the possible presence of deep faults in the bedrock in the upper strata of the study area,studies have shown that:(1)Magnetic isotopic contour maps and plane section diagrams in the shallow sea area of the northeastern part of Sanshan Island identify the high magnetic anomalies in the sea area to extend in the southeast direction,and are determined based on the analysis of the magnetic anomaly,continuation,and inversion results of the poles.The position of the magnetic rock mass divides the study into six magnetic anomalies.The bedrocks in the eastern and southern parts of the study area are relatively weak in magnetism,and the basement rocks in the western and northern parts of the study area have strong magnetic properties,and the northern part of the study area has the strongest bedrock magnetic properties.(2)Perform derivative conversion of magnetic anomalies,highlight local anomalies,and combine magnetic anomalies with analytical maps such as continuation and polarization to speculate that there are 6 NW trending faults and 1 NE trending fault.It is speculated that this fault may be three mountains.Island break in the shallow sea area.(3)Comprehensive seismic and borehole exploration data,determine the bedrock lithology of the magnetic anomaly zoning,and obtain the fractured bedrock fall from the seismic data,determine the fracture trend,and further determine the location and characteristics of the magnetic anomaly to explain the fracture.