The Application Of High Accuracy Magnetic Survey In The Magnetite Exploration In Western Australia

In geophysical survey methods,Magnetic survey is developed earliest and used most widely.High precision magnetic survey is mainly used in direct prospecting and indirect prospecting in solid mineral exploration.This paper studies the magnetic data of the western Australia area by high precision magnetic survey theory and method.The study is mainly about magnetic data processing and magnetic anomaly interpretation.Firstly,the paper briefly describes the present application situation of high precision magnetic survey,the significance and content of the study,and introduces the processes of how to determine the noise and consistent of magnetometer and measurement locations’ quality check;and then we ordered and pre-processed the data.The whole process of data acquisition and processing is in accordance with the ground high-precision magnetic survey standard.At last,we measured the parameters of specimens,and made a statistic analysis to study geophysical nature of the area.In the Δ Τ contour map,the magnetic anomalies can be clearly divided into three classes which are smooth positive anomalies,smooth negative anomalies and local anomalies.The smooth positive anomalies are widely distributed in north measured area,while the smooth negative anomalies are widely distributed in south measured area.Local anomalies are banded.The length of their is different,and the extension too.These local anomalies are scattered distributed in smooth positive and negative anomalies.The three constitute regional magnetic anomaly characteristics as a whole.Local magnetic anomalies are banded and mainly distributed in the north,east and south of the measured area.We select eight anomalies and numbered them C1、C2、C3、C4、C5、C6、C7、C8 from west to east.The anomalies have obviously extension direction,mainly distributed in the Cenozoic colluvium and Cenozoic red soil,limonite tuberculosis,especially Cenozoic red soil and limonite tuberculosis.Their border strictly controlled by the stratigraphic boundaries.In order to study the regional tectonic framework,we had a regularization filter processing of magnetic survey data.According to the results,we delineated five fracture structure,numbered F1,F2,F3,F4 and F2-1 from west to east.The measured area is above the archean erathem old formation background,regional metamorphism can make the iron in the old formation activate,precipitate along the crack and form ore deposits.By now,there are 60-70% of the world iron ore deposits were found in the old strata,it suggests that the geological environment is advantageous to iron ore formation.Based on the characteristics of geological environment and magnetic anomaly in the area,we screened two magnetic iron ore deposit prospecting target areas,which provide a basis for further ore-prospecting work.