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Global Geology 2018, 21(2) 127-133 DOI:
10.3969/j.issn.1673-9736.2018.02.06 ISSN: 1673-9736 CN: 22-1371/P |
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Combined analysis of gravity and magnetic anomalies using normalized source strength |
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LI Lu, ZHANG Shuang |
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College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China |
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The traditional combined gravity and magnetic analysis uses the linear regression of the first order vertical derivative of the gravity anomaly and the reduction to the pole (RTP) magnetic anomaly,and provides the quantitative or semi-quantitative interpretation by calculating the correlation coefficient,slope,and intercept.In the calculation process,due to the remanent magnetization,the RTP anomaly still contains the effect of oblique magnetization,as a result,the homologous gravity and magnetic anomalies may display irrelevant results in the linear regression calculation.To solve this problem,we present a new combined analysis using normalized source strength (NSS).Based on the Poisson's relation,the gravity field can be transformed into the pseudomagnetic field of the direction of geomagnetic field magnetization under the homologous condition.The NSS of the pseudomagnetic field and that of the original magnetic field are calculated,which are insensitive to the remanence,and then the linear regression analysis is carried out.The approach is tested using synthetic model under complex magnetization,the results show that it can still identify the gravity and magnetic anomalies from same source under strong remanence,and can establish the Poisson's ratio.Finally,this approach is applied in Wudalianchi in China.The results demonstrated that this approach is feasible and can provide the reference for further data processing and interpretation. |
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gravity anomaly
magnetic anomaly
normalized source strength
remanent magnetization
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Combined analysis of gravity and magnetic anomalies using normalized source strength |
|
|
LI Lu, ZHANG Shuang |
|
|
College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China |
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|
Abstract:
The traditional combined gravity and magnetic analysis uses the linear regression of the first order vertical derivative of the gravity anomaly and the reduction to the pole (RTP) magnetic anomaly,and provides the quantitative or semi-quantitative interpretation by calculating the correlation coefficient,slope,and intercept.In the calculation process,due to the remanent magnetization,the RTP anomaly still contains the effect of oblique magnetization,as a result,the homologous gravity and magnetic anomalies may display irrelevant results in the linear regression calculation.To solve this problem,we present a new combined analysis using normalized source strength (NSS).Based on the Poisson's relation,the gravity field can be transformed into the pseudomagnetic field of the direction of geomagnetic field magnetization under the homologous condition.The NSS of the pseudomagnetic field and that of the original magnetic field are calculated,which are insensitive to the remanence,and then the linear regression analysis is carried out.The approach is tested using synthetic model under complex magnetization,the results show that it can still identify the gravity and magnetic anomalies from same source under strong remanence,and can establish the Poisson's ratio.Finally,this approach is applied in Wudalianchi in China.The results demonstrated that this approach is feasible and can provide the reference for further data processing and interpretation. |
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Keywords:
gravity anomaly
magnetic anomaly
normalized source strength
remanent magnetization
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�ո����� 2017-12-05 ������ 2018-01-30 ����淢������ |
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DOI: 10.3969/j.issn.1673-9736.2018.02.06 |
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Supported by Project of National Natural Science Foundation of China (No.40930314) |
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