斜磁化磁异常处理方法分析
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摘要
受斜磁化的影响,磁异常特征复杂、不便于解释.强剩磁的存在、低纬度化极的困难等问题常常迫使人们直接针对斜磁化磁异常开展处理与反演.为了减小斜磁化的影响,磁异常总梯度模、分量模、磁异常梯度张量等处理方法得到广泛应用.本文基于理论分析,结合模型实验,分析现有斜磁化磁异常处理方法的优缺点,指出磁异常总梯度模、分量模、磁异常梯度张量等处理方法可能引起错误的地质解释,而采用适当的化极计算则可以明显改善解释效果.
The non-vertical magnetization anomaly shows a complex shape,and is hard to interpret. Considering the existed strong remanence as well as the unstable RTP at low latitude,people try to do processing and the inversion based on the non-vertical magnetization anomaly directly. To reduce the non-vertical effect,some methods,i. e. the Magnetic Total gradient( MTA), the Magnetic Amplitude( MMA),and the Magnetic tensor( MT),are widely used. In this study, we discuss the advantages and disadvantages for the existing method focusing on processing the non-vertical magnetization anomaly based on the theoretical analysis and the model studies. We state that in a complex geological case,the used processing methods,i. e. the MTA、MMA and the MT,may produce a pseudo anomaly and result in an incorrect geological interpretation. On the other hand,we show that using a proper RTP for the non-vertical magnetization anomaly can obtain a better interpretation.
The non-vertical magnetization anomaly shows a complex shape,and is hard to interpret. Considering the existed strong remanence as well as the unstable RTP at low latitude,people try to do processing and the inversion based on the non-vertical magnetization anomaly directly. To reduce the non-vertical effect,some methods,i. e. the Magnetic Total gradient( MTA), the Magnetic Amplitude( MMA),and the Magnetic tensor( MT),are widely used. In this study, we discuss the advantages and disadvantages for the existing method focusing on processing the non-vertical magnetization anomaly based on the theoretical analysis and the model studies. We state that in a complex geological case,the used processing methods,i. e. the MTA、MMA and the MT,may produce a pseudo anomaly and result in an incorrect geological interpretation. On the other hand,we show that using a proper RTP for the non-vertical magnetization anomaly can obtain a better interpretation.
引文
Ansari A H,Alamdar K.2009.Reduction to the pole of magnetic anomalies using analytic signal[J].World Applied Sciences Journal,7(4):405-409.
Beiki M,Clark D A,Austin J R,et al.2012.Estimating source location using normalized magnetic source strength calculated from magnetic gradient tensor data[J].Geophysics,77(6):J23-J37.
Beiki M,Keating P,Clark D A.2014.Interpretation of magnetic and gravity gradient tensor data using normalized source strength-a case study from Mc Faulds Lake,Northern Ontario,Canada[J].Geophysical Prospecting,62(5):1180-1192.
Clark D A.2009.Improved methods for interpreting magnetic gradient tensor data[C].//IAGA 11th Scientific Assembly.Sopron,Hungary:IAGA.
Clark D A.2013.New methods for interpretation of magnetic vector and gradient tensor data II:Application to the Mount Leyshon anomaly,Queensland,Australia[J].Exploration Geophysics,44(2):114-127.
Dannemiller N,Li Y G.2006.A new method for determination of magnetization direction[J].Geophysics,71(6):L69-L73.
Gerovska D,Araúzo-Bravo M J.2006.Calculation of magnitude magnetic transforms with high centricity and low dependence on the magnetization vector direction[J].Geophysics,71(5):I21-I30.
Gerovska D,Araúzo-Bravo M J,Stavrev P.2009.Estimating the magnetization direction of sources from southeast Bulgaria through correlation between reduced-to-the-pole and total magnitude anomalies[J].Geophysical Prospecting,57(4):491-505.
Guan Z N,Yao C L.1997.Inversion of the total gradient modulus of magnetic anomaly due to dipping dike[J].Earth Science-Journal of China University of Geosciences(in Chinese),22(1):81-85.
Hao T Y,Xu Y,Zhou L H,et al.2008.Integrated geophysical research on macroscopic distribution of Pre-Cenozoic residual basins-a case in Dagang area[J].Chinese J.Geophys.(in Chinese),51(2):491-502,doi:10.3321/j.issn:0001-5733.2008.02.021.
Li S L,Li Y G.2014.Inversion of magnetic anomaly on rugged observation surface in the presence of strong remanent magnetization[J].Geophysics,79(2):J11-J19.
Li Z L.2014.Research on 3-D inversion of magnetic data in the presence of strong remanence(in Chinese)[Master’s thesis].Beijing:China University of Geosciences(Beijing).
Li Z L,Yao C L,Zheng Y M,et al.2015.3D data-space inversion of magnetic amplitude data[J].Chinese J.Geophys.(in Chinese),58(10):3804-3814,doi:10.6038/cjg20151030.
Liu S,Feng J,Gao W L,et al.2013.2D inversion for borehole magnetic data in the presence of significant remanence and demagnetization[J].Chinese J.Geophys.(in Chinese),56(12):4297-4309,doi:10.6038/cjg20131232.
Nabighian M N.1972.The analytic signal of two-dimensional magnetic bodies with polygonal cross-section:Its properties and use for automated anomaly interpretation[J].Geophysics,37(3):507-517.
Oru9 B,Sert9elik I·,Kafadar,et al.2013.Structural interpretation of the Erzurum Basin,eastern Turkey,using curvature gravity gradient tensor and gravity inversion of basement relief[J].Journal of Applied Geophysics,88:105-113.
Ou Y,Liu T Y,Feng J,et al.2013.Inversion of magnetic total gradient modulus[J].Progress in Geophysics(in Chinese),28(5):2680-2687,doi:10.6038/pg20130550.
Pilkington M,Beiki M.2013.Mitigating remanent magnetization effects in magnetic data using the normalized source strength[J].Geophysics,78(3):J25-J32.
Ribeiro V B,Louro V H A,Mantovani M S M.2013.3D inversion of magnetic data of grouped anomalies-Study applied to S2o Joséintrusions in Mato Grosso,Brazil[J].Journal of Applied Geophysics,93:67-76.
Stavrev P,Gerovska D.2000.Magnetic field transforms with low sensitivity to the direction of source magnetization and high centricity[J].Geophysical Prospecting,48(2):317-340.
Wang L F,Guo C C,Xue D J,et al.2016.Analytic signals of magnetic gradient tensor and their application to estimate source location[J].Progress in Geophysics(in Chinese),31(3):1164-1172,doi:10.6038/pg20160333.
Zhang H L,Marangoni Y R,Hu X Y,et al.2014.NTRTP:A new reduction to the pole method at low latitudes via a nonlinear thresholding[J].Journal of Applied Geophysics,111:220-227.
Zhang H L,Marangoni Y R,Zuo R G,et al.2014.The improved anisotropy normalized variance for detecting non-vertical magnetization anomalies[J].Chinese J.Geophys.(in Chinese),57(8):2724-2731,doi:10.6038/cjg20140830.
Zhang J S.2000.The application of 3-D analytical signal technique to the treatment of aeromagnetic anomalies in South China[J].Geophysical and Geochemical Exploration,24(3):190-196.
管志宁,姚长利.1997.倾斜板体磁异常总梯度模反演方法[J].地球科学---中国地质大学学报,22(1):81-85.
郝天珧,徐亚,周立宏,等.2008.前新生代残留盆地宏观分布的综合地球物理研究---以大港地区为例[J].地球物理学报,51(2):491-502,doi:10.3321/j.issn:0001-5733.2008.02.021.
李泽林.2014.强剩磁条件下磁数据三维反演研究[硕士论文].北京:中国地质大学(北京).
李泽林,姚长利,郑元满,等.2015.数据空间磁异常模量三维反演[J].地球物理学报,58(10):3804-3814,doi:10.6038/cjg20151030.
刘双,冯杰,高文利,等.2013.强剩磁强退磁条件下的二维井中磁测反演[J].地球物理学报,56(12):4297-4309,doi:10.6038/cjg20131232.
欧洋,刘天佑,冯杰,等.2013.磁异常总梯度模量反演[J].地球物理学进展,28(5):2680-2687,doi:10.6038/pg20130550.
王林飞,郭灿灿,薛典军,等.2016.磁梯度张量解析信号分析法及其在场源位置识别中的应用[J].地球物理学进展,31(3):1164-1172,doi:10.6038/pg20160333.
张恒磊,Marangoni Y R,左仁广,等.2014.改进的各向异性标准化方差探测斜磁化磁异常源边界[J].地球物理学报,57(8):2724-2731,doi:10.6038/cjg20140830.
张季生.2000.用三维解析信号技术处理华南航磁异常[J].物探与化探,24(3):190-196.
Beiki M,Clark D A,Austin J R,et al.2012.Estimating source location using normalized magnetic source strength calculated from magnetic gradient tensor data[J].Geophysics,77(6):J23-J37.
Beiki M,Keating P,Clark D A.2014.Interpretation of magnetic and gravity gradient tensor data using normalized source strength-a case study from Mc Faulds Lake,Northern Ontario,Canada[J].Geophysical Prospecting,62(5):1180-1192.
Clark D A.2009.Improved methods for interpreting magnetic gradient tensor data[C].//IAGA 11th Scientific Assembly.Sopron,Hungary:IAGA.
Clark D A.2013.New methods for interpretation of magnetic vector and gradient tensor data II:Application to the Mount Leyshon anomaly,Queensland,Australia[J].Exploration Geophysics,44(2):114-127.
Dannemiller N,Li Y G.2006.A new method for determination of magnetization direction[J].Geophysics,71(6):L69-L73.
Gerovska D,Araúzo-Bravo M J.2006.Calculation of magnitude magnetic transforms with high centricity and low dependence on the magnetization vector direction[J].Geophysics,71(5):I21-I30.
Gerovska D,Araúzo-Bravo M J,Stavrev P.2009.Estimating the magnetization direction of sources from southeast Bulgaria through correlation between reduced-to-the-pole and total magnitude anomalies[J].Geophysical Prospecting,57(4):491-505.
Guan Z N,Yao C L.1997.Inversion of the total gradient modulus of magnetic anomaly due to dipping dike[J].Earth Science-Journal of China University of Geosciences(in Chinese),22(1):81-85.
Hao T Y,Xu Y,Zhou L H,et al.2008.Integrated geophysical research on macroscopic distribution of Pre-Cenozoic residual basins-a case in Dagang area[J].Chinese J.Geophys.(in Chinese),51(2):491-502,doi:10.3321/j.issn:0001-5733.2008.02.021.
Li S L,Li Y G.2014.Inversion of magnetic anomaly on rugged observation surface in the presence of strong remanent magnetization[J].Geophysics,79(2):J11-J19.
Li Z L.2014.Research on 3-D inversion of magnetic data in the presence of strong remanence(in Chinese)[Master’s thesis].Beijing:China University of Geosciences(Beijing).
Li Z L,Yao C L,Zheng Y M,et al.2015.3D data-space inversion of magnetic amplitude data[J].Chinese J.Geophys.(in Chinese),58(10):3804-3814,doi:10.6038/cjg20151030.
Liu S,Feng J,Gao W L,et al.2013.2D inversion for borehole magnetic data in the presence of significant remanence and demagnetization[J].Chinese J.Geophys.(in Chinese),56(12):4297-4309,doi:10.6038/cjg20131232.
Nabighian M N.1972.The analytic signal of two-dimensional magnetic bodies with polygonal cross-section:Its properties and use for automated anomaly interpretation[J].Geophysics,37(3):507-517.
Oru9 B,Sert9elik I·,Kafadar,et al.2013.Structural interpretation of the Erzurum Basin,eastern Turkey,using curvature gravity gradient tensor and gravity inversion of basement relief[J].Journal of Applied Geophysics,88:105-113.
Ou Y,Liu T Y,Feng J,et al.2013.Inversion of magnetic total gradient modulus[J].Progress in Geophysics(in Chinese),28(5):2680-2687,doi:10.6038/pg20130550.
Pilkington M,Beiki M.2013.Mitigating remanent magnetization effects in magnetic data using the normalized source strength[J].Geophysics,78(3):J25-J32.
Ribeiro V B,Louro V H A,Mantovani M S M.2013.3D inversion of magnetic data of grouped anomalies-Study applied to S2o Joséintrusions in Mato Grosso,Brazil[J].Journal of Applied Geophysics,93:67-76.
Stavrev P,Gerovska D.2000.Magnetic field transforms with low sensitivity to the direction of source magnetization and high centricity[J].Geophysical Prospecting,48(2):317-340.
Wang L F,Guo C C,Xue D J,et al.2016.Analytic signals of magnetic gradient tensor and their application to estimate source location[J].Progress in Geophysics(in Chinese),31(3):1164-1172,doi:10.6038/pg20160333.
Zhang H L,Marangoni Y R,Hu X Y,et al.2014.NTRTP:A new reduction to the pole method at low latitudes via a nonlinear thresholding[J].Journal of Applied Geophysics,111:220-227.
Zhang H L,Marangoni Y R,Zuo R G,et al.2014.The improved anisotropy normalized variance for detecting non-vertical magnetization anomalies[J].Chinese J.Geophys.(in Chinese),57(8):2724-2731,doi:10.6038/cjg20140830.
Zhang J S.2000.The application of 3-D analytical signal technique to the treatment of aeromagnetic anomalies in South China[J].Geophysical and Geochemical Exploration,24(3):190-196.
管志宁,姚长利.1997.倾斜板体磁异常总梯度模反演方法[J].地球科学---中国地质大学学报,22(1):81-85.
郝天珧,徐亚,周立宏,等.2008.前新生代残留盆地宏观分布的综合地球物理研究---以大港地区为例[J].地球物理学报,51(2):491-502,doi:10.3321/j.issn:0001-5733.2008.02.021.
李泽林.2014.强剩磁条件下磁数据三维反演研究[硕士论文].北京:中国地质大学(北京).
李泽林,姚长利,郑元满,等.2015.数据空间磁异常模量三维反演[J].地球物理学报,58(10):3804-3814,doi:10.6038/cjg20151030.
刘双,冯杰,高文利,等.2013.强剩磁强退磁条件下的二维井中磁测反演[J].地球物理学报,56(12):4297-4309,doi:10.6038/cjg20131232.
欧洋,刘天佑,冯杰,等.2013.磁异常总梯度模量反演[J].地球物理学进展,28(5):2680-2687,doi:10.6038/pg20130550.
王林飞,郭灿灿,薛典军,等.2016.磁梯度张量解析信号分析法及其在场源位置识别中的应用[J].地球物理学进展,31(3):1164-1172,doi:10.6038/pg20160333.
张恒磊,Marangoni Y R,左仁广,等.2014.改进的各向异性标准化方差探测斜磁化磁异常源边界[J].地球物理学报,57(8):2724-2731,doi:10.6038/cjg20140830.
张季生.2000.用三维解析信号技术处理华南航磁异常[J].物探与化探,24(3):190-196.