GEOPHYSICAL RESEARCH2018, vol. 19, no. 3, pp. 23-40.

UDC 550.838.2, 550.837.32

Abstract  References   Full text (in Russian)


V.A. Lubchich

Polar Geophysical Institute, Murmansk, Russia

Abstract. The article deals with the investigation of fractal properties of geophysical data arrays, obtained in the Monchegorsk ore region as a result of areal magnetic surveys and geoelectrical surveys by the method of small-scale charge. The ore region is located in the Central part of the Pechenga-Varzugskaya riftogenic structure. This circumstance causes the presence of the hierarchically organized system of tectonic dislocations of various scales and directions in the region. Main structural longitudinal axial faults of the North-West direction and transform faults of the North-East direction together with concomitant tectonic zones of smaller scales control the placement of intrusive massifs of basic-ultrabasic rocks and define the structure of deposits and occurrences of rich epigenetic copper-nickel ores, thus forming the Monchegorsk ore-magmatic system of the Central type. The hierarchical organization of geological systems determines fractal properties of geophysical data arrays, obtained in the result of areal measurements on these systems. So the network of tectonic faults is displayed in geophysical fields as the set of anomalous zones with the high electrical conductivity. The fractal dimension of this set, estimated by the cell method, is df =1.38±0.02. Moreover ore zones are clearly displayed in the magnetic field due to the wide spread of magnetic ore minerals such as pyrrhotite and magnetite. It was shown on the example of magnetic survey data in the Monchegorsk ore region, that the two-dimensional wavelet analysis is useful tool to study fractal properties of geophysical data arrays. The application of the wavelet analysis allows to detect the hierarchical structure of organization of the whole geological system and to conclude about its local properties, for example, ore prospects of separate areas. The average value of local singularity exponents al, calculated for separate ridges of the skeleton of the wavelet transform, may be used as the quantitative characteristic of the magnetic field inhomogeneity within the investigated area. Zones, promising discovery of rich epigenetic copper-nickel ores, are characterized by the strongly inhomogeneous magnetic field, and corresponding local singularity exponents have smaller values. Areas with the predominantly low and medium level of disseminated mineralization are characterized by the more homogeneous magnetic field, and corresponding local singularity exponents are close to unity.

Keywords: copper-nickel ore, tectonic fault, magnetic field, the method of small-scale charge, fractal dimension, wavelet transform, local singularity exponent.


Astafjeva N.M., Wavelet analysis: principles of theory and application examples. Physics-Uspekhi (Advances in Physical Sciences), 1996, vol. 166 (11), pp. 1145-1170.

Bansal A.R. and Dimri V.P., Depth determination from nonstationary magnetic profile for multi scaling geology, Geophysical Prospecting, 2005, vol. 53, pp. 399-410.

Bansal A.R. and Dimri V.P., Gravity evidence for mid crustal structure below Delhi fold belt and Bhilwara super group of western India, Geophys. Res. Lett., 1999, vol. 26, pp. 2793-2795.

Chamoli A. and Dimri V.P., Evidence of continental crust over Laxmi Basin (Arabian Sea) using wavelet analysis, Indian Journal of Marine Sciences, 2007, vol. 36, no. 2, pp. 117-121.

Chamoli A., Pandey A.K., Dimri V.P., and Banerjee P., Crustal configuration of the northwest Himalaya based on modeling of gravity data, Pure and Applied Geophysics, 2011, vol. 168, is. 5, pp. 827-844.

Chamoli A., Srivastava R.P., and Dimri V.P., Source depth characterization of potential field data of Bay of Bengal by continuous wavelet transform, Indian Journal of Marine Sciences, 2006, vol. 35, no. 3, pp. 195-204.

Feder J., Fractals, New York: Plenum Press, 1988.

Fedi M., Quarta T., and Sanits A.D., Inherent power-law behavior of magnetic field power spectra from a Spector and Grant ensemble, Geophysics, 1997, vol. 62, pp. 1143-1150.

Fractal Behaviour of the Earth System, Editor V.P. Dimri, New York: Springer, 2005.

Gorjainov P.M. and Ivanjuk G.Ju., Samoorganizaciya mineralnyh sistem. Sinergeticheskie principy geologicheskih issledovanij (Self-organization of mineral systems. Synergetic principles of geological research), Moscow: Geos, 2001.

Gumiel P., Sanderson D.J., Arias M., Roberts S., and Martin-Izard A., Analysis of the fractal clustering of ore deposits in the Spanish Iberian Pyrite Belt, Ore Geology Review, 2010, vol. 38, is. 4, pp. 307-318.

Lubchich V.A., Izuchenie fraktalnyh svojstv geologicheskih sred metodami geoelektriki. (The investigation of fractal properties of geological media by using methods of geoelectrics), Saarbrucken: LAP LAMBERT Academic Publishing GmbH & Co, 2012. ISBN: 978-3-8465-9959-4.

Lubchich V.A., Investigation of fractal properties of the magnetic survey data array in the Pechenga ore region using two-dimensional wavelet analysis. Russian Geology and Geophysics, 2017, vol. 58, Is. 9, pp. 1129-1137.

Mandelbrot B.B., The fractal geometry of nature, San Francisco: W.H. Freeman & Co, 1982.

Maus S. and Dimri V.P., Potential field power spectrum inversion for scaling geology, J. Geophys. Res., 1995, vol. 100, pp. 12605-12616.

Maus S. and Dimri V.P., Scaling properties of potential fields due to scaling sources, Geophys. Res. Lett., 1994, vol. 21, pp. 891-894.

McCaffrey K.J.W. and Johnston J.D., Fractal analysis of a mineralized vein deposit: Curraghinalt gold deposit, County Tyrone, Mineralium Deposita, 1996, vol. 31, pp. 52-58.

Medno-nikelevye mestorozhdenija Baltijskogo shchita (Copper-Nickel deposits of the Baltic shield), Editors G.I. Gorbunov and H. Papunen, Leningrad: Nauka, 1985.

Pilkington M. and Todoeschuck J.P., Fractal magnetization of continental crust, Geophysical Research Letters, 1993, vol. 20, pp. 627-630.

Raines G.L., Are fractal dimensions of the spatial distribution of mineral deposits meaningful?, Natural Resources Research, 2008, vol. 17, is. 2, pp. 87-97.

Rodkin M.V., Zotov I.A., Grayeva E.M., Labuntsova L.M., Shatakhtsyan A.R., Power distributions in ore and oil genesis – interpretation and generating mechanisms. Russian journal of Earth sciences, 2010, vol. 11, RE3005, doi: 10.2205/2009ES000408

Smolencev N.K., Osnovy teorii vejvletov. Vejvlety v MATLAB (Principles of the theory of wavelets. Wavelets in MATLAB), Moscow: DMK Press, 2005.

Turcottee D.L., Fractals and Chaos in Geology and Geophysics, New York: Cambridge University Press, 1992.

Wavelets and Fractals in Earth System Sciences, Editors E. Chandrasekhar, V.P. Dimri and V.M. Gadre, Boca Raton, London, New York: CRC Press, Taylor & Francis Group, 2013.