1887
Volume 52, Issue 5
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Geomagnetic measurements detect the superposition of both regional and residual anomalies. Regional anomalies are caused by deep geological structures, while the residual ones are due to shallow sources. The presence of regional anomalies complicates the interpretation of magnetic data; to this end, a variety of techniques have been proposed for regional-residual anomaly separation. Most of them are based on Fourier transforms. Although valid results can be obtained from these methods, they have some limitations, such as requiring basic knowledge on approximate cut-off frequencies. This study focuses on spatial filtering employing factorial kriging (FK) for geomagnetic anomaly separation. FK employs geostatistical filtering based on spatial dependencies of the data. In contrast to the upward continuation, which is a trial and error method and needs to be checked with different distances of continuations, the utilisation of FK on synthetic data revealed that FK could automatically perform the separation and also helps to find the optimum distance for the upward continuation method. Following experiments with a synthetic model, the method was applied to real magnetic data of Bashmaq in northwestern Iran. Applying FK on a complicated real case study showed that it could separate the regional and residual components satisfactorily. Furthermore, results from the proposed approach have been compared against the Gaussian Separation Method (GSM). The results are compared to borehole information. The lithological columns are presented as part of the geology investigation. As demonstrated in the case study, the FK method has proven to be an accurate tool to better determine the mineralisation zones compared to GSM, which, in turn, facilitates the interpretation.

© 2020 Australian Society of Exploration Geophysicists
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2021-09-03
2026-01-20

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References

  1. Albora, A.M., A.Özmen, and O.N.Ucan. 2001. Residual separation of magnetic fields using a cellular neural network approach. Pure and Applied Geophysics158: 1797–818. doi: 10.1007/PL00001244
     https://doi.org/10.1007/PL00001244 [Google Scholar]
  2. Azad, M.-R., M.Koneshloo, A.K.Rouhani, and H.Aghajani. 2016. Comparison of factorial kriging analysis method and upward continuation filter to recognize subsurface structures – a case study: Gravity data from a hydrocarbon field in the southeast sedimentary basins of the East Vietnam Sea. Acta Geophysica64: 398–416. doi: 10.1515/acgeo‑2015‑0068
     https://doi.org/10.1515/acgeo-2015-0068 [Google Scholar]
  3. Beltrao, J., J.Silva, and J.Costa. 1991. Robust polynomial fitting method for regional gravity estimation. Geophysics56: 80–9. doi: 10.1190/1.1442960
     https://doi.org/10.1190/1.1442960 [Google Scholar]
  4. Bourges, M., J.-L.Mari, and N.Jeannée. 2012. A practical review of geostatistical processing applied to geophysical data: Methods and applications. Geophysical Prospecting60: 400–12. doi: 10.1111/j.1365‑2478.2011.00992.x
     https://doi.org/10.1111/j.1365-2478.2011.00992.x [Google Scholar]
  5. Chen, G., and Q.Cheng. 2018. Fractal-based wavelet filter for separating geophysical or geochemical anomalies from background. Mathematical Geosciences50: 249–72. doi: 10.1007/s11004‑017‑9707‑9
     https://doi.org/10.1007/s11004-017-9707-9 [Google Scholar]
  6. Cowan, D., and S.Cowan. 1993. Separation filtering applied to aeromagnetic data. Exploration Geophysics24: 429–36. doi: 10.1071/EG993429
     https://doi.org/10.1071/EG993429 [Google Scholar]
  7. de Carvalho, P.R.M., L.G.Rasera, J.F.C.L.Costa, M.G.S.Araújo, and L.E.S.Varella. 2019. Variogram modeling of broadband artifacts of a seafloor map for filtering with factorial kriging. Journal of Applied Geophysics161: 92–104. doi: 10.1016/j.jappgeo.2018.12.009
     https://doi.org/10.1016/j.jappgeo.2018.12.009 [Google Scholar]
  8. Dentith, M., and S.T.Mudge. 2014. Geophysics for the mineral exploration geoscientist. Chicago: Cambridge University Press.
  9. Fedi, M., and T.Quarta. 1998. Wavelet analysis for the regional-residual and local separation of potential field anomalies. Geophysical Prospecting46: 507–25. doi: 10.1046/j.1365‑2478.1998.00105.x
     https://doi.org/10.1046/j.1365-2478.1998.00105.x [Google Scholar]
  10. Galli, A., F.Gerdil-Neuillet, and C.Dadou. 1984. Factorial kriging analysis: A substitute to spectral analysis of magnetic data. In Geostatistics for natural resources characterization, ed. G. Verly, M. David, A.G. Journel, and A. Marecha, 543–57. Springer.
     [Google Scholar]
  11. Goovaerts, P.1992. Factorial kriging analysis: A useful tool for exploring the structure of multivariate spatial soil information. Journal of Soil Science43: 597–619. doi: 10.1111/j.1365‑2389.1992.tb00163.x
     https://doi.org/10.1111/j.1365-2389.1992.tb00163.x [Google Scholar]
  12. Griffin, W.R.1949. Residual gravity in theory and practice. Geophysics14: 39–56. doi: 10.1190/1.1437506
     https://doi.org/10.1190/1.1437506 [Google Scholar]
  13. Jaquet, O.1989. Factorial kriging analysis applied to geological data from petroleum exploration. Mathematical Geology21: 683–91. doi: 10.1007/BF00893316
     https://doi.org/10.1007/BF00893316 [Google Scholar]
  14. Jiménez-Espinosa, R., and M.Chica-Olmo. 1999. Application of geostatistics to identify gold-rich areas in the Finisterre-Fervenza region, NW Spain. Applied Geochemistry14: 133–45. doi: 10.1016/S0883‑2927(98)00035‑3
     https://doi.org/10.1016/S0883-2927(98)00035-3 [Google Scholar]
  15. Kaftan, I., M.Salk, and C.Sari. 2005. Application of the finite element method to gravity data case study: Western Turkey. Journal of Geodynamics39: 431–43. doi: 10.1016/j.jog.2005.04.003
     https://doi.org/10.1016/j.jog.2005.04.003 [Google Scholar]
  16. Kane, M.1985. Analysis of regional gravity maps using wavelength-filtering techniques. Seg Technical Program Expanded Abstracts 1985, Society of Exploration Geophysicists, 196-96.
  17. Li, Y., and D.W.Oldenburg. 1998. Separation of regional and residual magnetic field data. Geophysics63: 431–9. doi: 10.1190/1.1444343
     https://doi.org/10.1190/1.1444343 [Google Scholar]
  18. Liu, C.-Y., C.-L.Yao, and J.Xiong. 2019. Geophysical potential field anomaly separation method with optimal mother wavelet and spatial locating multiresolution analysis (MRA). IEEE Access7: 62840–51. doi: 10.1109/ACCESS.2019.2913671
     https://doi.org/10.1109/ACCESS.2019.2913671 [Google Scholar]
  19. Ma, Y.2019. Geostatistical variography for geospatial variables. In Quantitative geosciences: Data analytics, geostatistics, reservoir characterization and modeling, ed. Y.Z. Ma, 301–30. Springer.
     [Google Scholar]
  20. Mallick, K., and K.Sharma. 1999. A finite element method for computation of the regional gravity anomaly. Geophysics64: 461–9. doi: 10.1190/1.1444551
     https://doi.org/10.1190/1.1444551 [Google Scholar]
  21. Mallick, K., A.Vasanthi, and K.K.Sharma. 2012. Bouguer gravity regional and residual separation: Application to geology and environment. Dordrecht: Springer Science & Business Media.
  22. Meunier, R., M.Bourges, H.Binet, N.Jeannée, L.Wagner, and D.Renard. 2013. Geostatistical filtering of 4D seismic data: Methods and benefits. 13th International Congress of the Brazilian Geophysical Society & EXPOGEF, 1432–4, August 26–29, in Rio de Janeiro, Brazil.
  23. Mickus, K.L., C.L.Aiken, and W.Kennedy. 1991. Regional-residual gravity anomaly separation using the minimum-curvature technique. Geophysics56: 279–83. doi: 10.1190/1.1443041
     https://doi.org/10.1190/1.1443041 [Google Scholar]
  24. Muharina, G.N., I.Setiadi, B.Santoso, and E.Supriyana. 2019. Delineation of sedimentary sub-basin and basement configuration based on the upward continuation filter and 2D and 3D modeling of gravity data (a case study: Rembang area and its surroundings). IOP Conference Series: Earth and Environmental Science311: 012061. doi: 10.1088/1755‑1315/311/1/012061
     https://doi.org/10.1088/1755-1315/311/1/012061 [Google Scholar]
  25. Nabighian, M.N., V.Grauch, R.Hansen, T.LaFehr, Y.Li, J.Peirce, J.Phillips, and M.Ruder. 2005. The historical development of the magnetic method in exploration. Geophysics70: 33ND–61ND. doi: 10.1190/1.2133784
     https://doi.org/10.1190/1.2133784 [Google Scholar]
  26. Pawlowski, R.S., and R.Hansen. 1990. Gravity anomaly separation by Wiener filtering. Geophysics55: 539–48. doi: 10.1190/1.1442865
     https://doi.org/10.1190/1.1442865 [Google Scholar]
  27. Remy, N., A.Boucher, and J.Wu. 2009. Applied geostatistics with SGeMS: A user's guide. Cambridge UniversityCambridge: Press.
  28. Ridsdill-Smith, T.A.1998. Separation filtering of aeromagnetic data using filter-banks. Exploration Geophysics29: 577–83. doi: 10.1071/EG998577
     https://doi.org/10.1071/EG998577 [Google Scholar]
  29. Roach, M., D.Leaman, and R.Richardson. 1993. A comparison of regional-residual separation techniques for gravity surveys. Exploration Geophysics24: 779–84. doi: 10.1071/EG993779
     https://doi.org/10.1071/EG993779 [Google Scholar]
  30. Shamsipour, P., M.Chouteau, and D.Marcotte. 2017. Data analysis of potential field methods using geostatistics. Geophysics82: G35–44. doi: 10.1190/geo2015‑0631.1
     https://doi.org/10.1190/geo2015-0631.1 [Google Scholar]
  31. Syberg, F.1972. A Fourier method for the regional-residual problem of potential fields. Geophysical Prospecting20: 47–75. doi: 10.1111/j.1365‑2478.1972.tb00619.x
     https://doi.org/10.1111/j.1365-2478.1972.tb00619.x [Google Scholar]
  32. Ucan, O.N., S.Seker, A.M.Albora, and A.Ozmen. 2000. Separation of magnetic fields in geophysical studies using a 2-D multi-resolution wavelet analysis approach. Journal of the Balkan Geophysical Society3: 53–8.
     [Google Scholar]
  33. Warr, B., M.Oliver, and K.White. 2002. The application offactorial kriging and Fourier analysis for remotely sensed data simplification and feature accentuation. Geographical and Environmental Modelling6: 171–87. doi: 10.1080/1361593022000029485
     https://doi.org/10.1080/1361593022000029485 [Google Scholar]
  34. Weiland, W.L.1989. Integrated approach to gravity anomaly separation by geologic stripping. Seg Technical Program Expanded Abstracts 1989, Society of Exploration Geophysicists, 325–8.
  35. Wen, R., and R.Sinding-Larsen. 1997. Image filtering by factorial kriging – sensitivity analysis and application to Gloria side-scan sonar images. Mathematical Geology29: 433–68. doi: 10.1007/BF02775083
     https://doi.org/10.1007/BF02775083 [Google Scholar]
  36. Wu, F.-C., C.-K. Wang, and G.-H. Huang. 2018. Delineation of gravel-bed clusters via factorial kriging. Geomorphology 308: 161–74.
  37. Xu, Y., T.Hao, Z.Li, Q.Duan, and L.Zhang. 2009. Regional gravity anomaly separation using wavelet transform and spectrum analysis. Journal of Geophysics and Engineering6: 279–87. doi: 10.1088/1742‑2132/6/3/007
     https://doi.org/10.1088/1742-2132/6/3/007 [Google Scholar]
  38. Yang, W.C., Z.Q.Shi, and Z.Z.Hou. 2001. Discrete wavelet transform for multiple decomposition of gravity anomalies. Chinese Journal of Geophysics44: 529–37. doi: 10.1002/cjg2.171
     https://doi.org/10.1002/cjg2.171 [Google Scholar]
  39. Zeng, H., D.Xu, and H.Tan. 2007. A model study for estimating optimum upward-continuation height for gravity separation with application to a Bouguer gravity anomaly over a mineral deposit, Jilin Province, Northeast China. Geophysics72: I45–50. doi: 10.1190/1.2719497
     https://doi.org/10.1190/1.2719497 [Google Scholar]
  40. Zhang, L., T.Hao, and W.Jiang. 2009. Separation of potential field data using 3-D principal component analysis and textural analysis. Geophysical Journal International179: 1397–413. doi: 10.1111/j.1365‑246X.2009.04357.x
     https://doi.org/10.1111/j.1365-246X.2009.04357.x [Google Scholar]
/content/journals/10.1080/08123985.2020.1845095
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Separation of geomagnetic anomalies in the Bashmaq area in northwestern Iran by factorial kriging
Exploration Geophysics 52, 540 (2021); https://doi.org/10.1080/08123985.2020.1845095
/content/journals/10.1080/08123985.2020.1845095
/content/journals/10.1080/08123985.2020.1845095
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  • Article Type: Research Article
Keyword(s): decomposition; filtering; geomagnetism; potential fields; Regional studies; separation

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