Study On Distribution Characteristics And Attributes Of Magnetic Bodies In Hanzhong Basin And Its Adjacent Areas

The Hanzhong Basin has a complex structure and a lower geological and geophysical research.The Previous research mainly focused on tectonic evolution on the Hanzhong Basin and its adjacent areas,and very few research on the distribution characteristics of the magnetic bodies in the basin.The research on the distribution characteristics and attributes of magnetic bodies in the Hanzhong Basin,can provide a geophysical basis for further basic geology research in the Hanzhong Basin.Based on the 1:500,000 aeromagnetic data in the Hanzhong Basin,through analytical continuation,moving average,the vertical second derivative,the total horizontal gradient processed magnetic data,combined with previous research results on the geological structure of the Hanzhong Basin,seismic data interpretation and gravity data.this paper studies the magnetic anomalies in the Hanzhong Basin and its adjacent areas,analyzes the characteristics of magnetic anomalies,and discusses the distribution characteristics and attributes of magnetic bodies.This article has achieved the following main results and conclusions:(1)The magnetic anomaly in the Hanzhong Basin and its adjacent areas has obvious zoning,magnetic bodies are developed,and the lithology of the basement has changed greatly.Strong magnetic rocks have been developed along large fault zones,mainly Archean-proterozoic metamorphic rocks,proterozoic granites,and basic-ultrabasic intrusive rocks.Fourteen magnetic bodies can be identified in the Hanzhong Basin and its adjacent areas,which vary in size and shape,and are generally distributed in four areas.The characteristics of magnetic bodies developed in different tectonic units are different.(2)The magnetic anomaly in the Hanzhong Basin is caused by the combination of the uplift of the metamorphic basement in the Yangtze platform and the intrusion of the strongly magnetic rock masses.The magnetic anomalies around the Hanzhong Basin are complex.The magnetic anomalies in the Qinling strong fault uplift zone and the Longmenshan strong fault uplift zone are caused by basement uplift and old strata outcrops,and some magnetic anomalies are only caused by strong magnetic rocks on the surface.The South China New Tectonic Area is highly active.The Hannan complex in this area is composed of multi-phase magmatic intrusions,with large changes in lithology.The magnetic bodies are Archaean-Proterozoic basic-ultrabasic rocks,which are basically distributed in southern Hannan Boundary of rocks.(3)The burial depth of the developed magnetic body M-9 in Hanzhong Basin is about1500-3000m,and its thickness is between 3000-4000m.According to the determined range of the magnetic body,the area of the magnetic body M-9 in Hanzhong is about 370.58km~2,and the volume is about 960km~3.The distribution characteristics of the magnetic bodies in the Hanzhong Basin suggest the east-west difference in tectonic movements(mainly vertical movements)in the Hanzhong Basin.