Skip to main content
Log in

Geomagnetic Field Variations as Determined from Bulgarian Archaeomagnetic Data. Part II: The Last 8000 Years

  • Published:
Surveys in Geophysics Aims and scope Submit manuscript

Abstract

The knowledge about past secular variations of the geomagnetic field is achieved on the basis of archaeomagnetic researches of which the Bulgarian studies form an extended data set. In Part I (Kovacheva and Toshkov, 1994), the methodology used in the Sofia palaeomagnetic laboratory was described and the secular variation curves for the last 2000 years were shown. In Part II (this paper), the basic characteristics of the prehistoric materials used in the archaeomagnetic studies are emphasised, particularly in the context of the rock magnetic studies used in connection with palaeointensity determinations. The results of magnetic anisotropy studies of the prehistoric ovens and other fired structures are summarised, including the anisotropy correction of the palaeointensity results for prehistoric materials, different from bricks and pottery. Curves of the direction and intensity of the geomagnetic field during the last 8000 years in Bulgaria are given. The available directional and intensity values have been used to calculate the variation curve of the virtual dipole moment (VDM) for the last 8000 years based on different time interval averages. The path of virtual geomagnetic pole (VGP) positions is discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Aitken, M., Allsop, A., Bussell, G. and Winter, M.: 1986, ‘Palaeointensity determination using the Thellier Technique: Reliability criteria’, J. Geomag. Geoelectr. 38, 1353-1363.

    Google Scholar 

  • Aitken, M., Allsop, A., Bussell, G., and Winter, M.: 1988, ‘Determination of the intensity of the Earth's magnetic field during archaeological times. Reliability of the Thellier technique’, Rev. Geophys. 26(1), 3-12.

    Google Scholar 

  • Barbetti, M.F., McElhinny, M.W., Eduards, D.J., and Schmidt, P.W.: 1977, ‘Weathering processes in baked sediments and their effects on archaeomagnetic field-intensity measurements’, Phys. Earth Plan. Inter. 13, 346-356.

    Google Scholar 

  • Boyadziev, Y.: 1995, ‘Chronology of prehistoric cultures in Bulgaria’, in D. Bailey and I. Panayotov (eds), Prehistoric Bulgaria, Monographs in World Archaeology, No. 22, Prehistory Press, Madison Wisconsin, pp. 149-192.

    Google Scholar 

  • Burlatskaja, S.: 1984, ‘Movement of the virtual geomagnetic pole’, Izvestia Acad. Nauk SSSR, Physic of the Earth 2, 41-50 (in Russian).

    Google Scholar 

  • Chauvin, A., Gillot, P.Y., and Bonhommet, N.: 1991, ‘Palaeointensity of the Earth's magnetic field, recorded by two late quaternary sequences at the island of La Reunion (Indian Ocean)’, J. Geophys. Res. 96, B2, 1981-2006.

    Google Scholar 

  • Coe, R.S.: 1967, ‘The determination of paleo-intensities of the Earth's magnetic field with emphasis on mechanisms which could cause non-ideal behaviour in Thellier's method’, J. Geomagn. Geoelectr. 19(3), 157-179.

    Google Scholar 

  • Cui, Y. and Verosub, K.L.: 1995, ‘A mineral magnetic study of some pottery samples: possible implications for sample selection in archaeointensity studies’, Phys. Earth Plan. Inter. 91, 261-271.

    Google Scholar 

  • Cui, Y., Verosub, K.L., Roberts, A.P., and Kovacheva, M.: 1997, ‘Rock magnetic studies of archaeological samples: implications for sample selection for paleointensity determinations’, J. Geomagn. Geoelectr. 49, 567-585.

    Google Scholar 

  • Daly, L. and Le Goff, M.: 1996, ‘An updated and homogeneous world secular variation data base. 1. Smoothing of the archaeomagnetic results’, Phys. Earth Plan. Inter. 93, 159-190.

    Google Scholar 

  • Dawson, E. and Newitt, L.: 1982, ‘The magnetic Poles of the Earth’, J. Geomag. Geoelectr. 34, 225-240.

    Google Scholar 

  • Day, R., Fuller, M., and Schmidt, V.A.:1977, ‘Hysteresis properties of titanomagnetites: grain-size and compositional dependence’, Phys. Earth Plan.Inter. 13, 260-267.

    Google Scholar 

  • De Boer, C.B. and Dekkers, M.J.: 1996, ‘Grain-size dependence of the rock magnetic properties for a natural maghemite’, Geophys. Research Lett. 23(20), 2815- 2818.

    Google Scholar 

  • Derder, M., Messaoud, El., Thompson, J., Prevot, M., and McWilliams, M.:1989, ‘Geomagnetic field intensity in Early Jurassic - investigation of the Newarc Supergroup (ENA)’, Phys. Earth Plan.Inter. 58, 126-136.

    Google Scholar 

  • Dunlop, D.: 1983, ‘Determination of domain structure in igneous rocks by alternating field and other methods’, Earth Plan. Sci. Lett. 63, 353-367.

    Google Scholar 

  • Evans, M. and Jiang, L.: 1996, ‘Magnetomineralogy of archaeomagnetic minerals’, J. Geomag. Geoelectr. 48, 1531-1540.

    Google Scholar 

  • Fisher, R.A.: 1953, ‘Dispersion on a sphere’, Proceedings of Royal Society, London A217, p. 295.

  • Haag, M., Dunn, J.R., and Fuller, M.: 1995, ‘A new quality check for absolute palaeointensities of the Earth magnetic field’, Geophys. Res. Lett. 22, 3549-3552.

    Google Scholar 

  • Hongre, L., Hulot, G., and Khokhlov, A.: 1998, ‘An analysis of the geomagnetic field over the past 2000 years’, Phys. Earth Plan. Inter. 106(3-4), 311-335.

    Google Scholar 

  • Hulot, G. and Le Mouel, J.: 1994, ‘A statistical approach to the Earth's main magnetic field’, Phys. Earth Plan.Inter. 82, 167-183.

    Google Scholar 

  • Jackson, M.: 1991, ‘Anisotropy of magnetic remanence: A brief review of mineralogical sources, physical origins and geological applications, and comparison with susceptibility anisotropy’, Pageoph. 136(1), 1-28.

    Google Scholar 

  • Jelinek, V.: 1981, ‘Characterisation of the magnetic fabrics of rocks’, Tectonophysics 79, T63-T67.

    Google Scholar 

  • Jordanova, N.: 1996, ‘Rock magnetic studies in archaeomagnetism and their contribution to the problem of reliable determination of the ancient geomagnetic field intensity’, Ph.D., Sofia (in Bulgarian).

  • Jordanova, N., Karloukovski V., and Spatharas, V.: 1995, ‘Magnetic anisotropy studies on Greek pottery and bricks’, Bulg. Geophys. J. XXI (4), 49-58.

    Google Scholar 

  • Jordanova, N., Petrovsky, E., and Kovacheva, M.: 1997, ‘Preliminary rock magnetic study of archaeomagnetic samples from Bulgarian prehistoric sites’, J. Geomag. Geoelectr. 49, 543-566.

    Google Scholar 

  • King, J.W., Banerjee, S.K., and Marvin, J.: 1983, ‘A new rockmagnetic approach to selecting sediments for geomagnetic paleointensity studies: Application to paleointensity for the last 40,000 years’, J. Geophys. Res. 88, 5911-5921.

    Google Scholar 

  • Kovacheva, M.: 1980, ‘Summarized results of the archaeomagnetic investigation of the geomagnetic field variation for the last 8,000 years in South Eastern Europe’, Geophys. J. R. Astr. Soc., 61, 57-64.

    Google Scholar 

  • Kovacheva, M.: 1992, ‘Updated archaeomagnetic results from Bulgaria: the last 2000 years’, Phys. Earth Plan. Inter. 70, 219-223.

    Google Scholar 

  • Kovacheva, M.: 1995, ‘Bulgarian Archaeomagnetic studies’, in D. Bailey and I. Panayotov (eds), Prehistoric Bulgaria, Monographs in World Archaeology, No. 22, Prehistory Press, Madison Wisconsin, pp. 209-224.

    Google Scholar 

  • Kovacheva, M.: 1997, ‘Archaeomagnetic database from Bulgaria: the last 8000 years’, Phys. Earth Plan. Inter. 102, 145-151.

    Google Scholar 

  • Kovacheva, M. and Kanarchev, M.: 1986, ‘Revised archaeointensity data from Bulgaria’, J. Geomag. Geoelectr. 38, 1297-1310.

    Google Scholar 

  • Kovacheva, M. and Toshkov, A.: 1994, ‘Geomagnetic field variations as determined from Bulgarian archaeomagnetic data. Part I: The last 2000 years AD’, Surveys in Geophysics 15, 673-701.

    Google Scholar 

  • Kovacheva, M., Chauvin, A., Jordanova, N., and Karloukovski, V.: ‘Archaeointensity study: inter laboratory comparison, anisotropy effect in the baked clay from ovens and ancient fires’, Phys. Earth Plan. Inter, in press.

  • Lanos, P.: in press, ‘Bayesian approach using penalized maximum likelihood to smoothing time series carring errors both on time and measure’.

  • Le Goff, M., Kovacheva, M., Lanos, P., and Daly, L.: ‘Bulgarian archaeomagnetic data covering an eight millennia period: a comparison of smoothing procedures’, in press.

  • Levi, S. and Banerjee, S.K.: 1976, ‘On the possibility of obtaining relative paleointensities from lake sediments’, Earth Planet. Sci. Let. 29, 219-2226.

    Google Scholar 

  • Lowrie, W. and Fuller, M.: 1971, ‘On the alternating field demagnetization characteristics of multidomain thermoremanent magnetization in magnetite’, J. Geophys. Res. 76(26), 6339-6349.

    Google Scholar 

  • Lowrie, W.: 1990, ‘Identification of ferromagnetic minerals in a rock by coercivity and unblocking temperature properties’, Geophys. Res. Lett. 17(2), 159-162.

    Google Scholar 

  • McElhinny, M. and Senanayake, W.: 1982, ‘Variations in the geomagnetic dipole I: The past 50,000 years’, J. Geomag. Geoelectr. 34, 39-51.

    Google Scholar 

  • Ohno, M. and Humano, Y.: 1992, ‘Geomagnetic poles over the past 10,000 years’, Geophys. Res. Lett. 19, 1715-1718.

    Google Scholar 

  • Osipov, J.B.: 1978, ‘Magnetism of soils’, Nedra, Moskow (in Russian).

  • Ozdemir, O. and Banerjee, S.K.: 1984, ‘High temperature stability of maghemite (γ-Fe2O3)’, Geophys. Res. Lett. 11(3), 161-164.

    Google Scholar 

  • Ozdemir, O. and Dunlop, D.: 1993, ‘Chemical remanent magnetization during γ FeOOH phase transformations’, J. Geophys. Res. 98, B3, 4191-4198.

    Google Scholar 

  • Pick, T. and Tauxe, L.: 1993, ‘Holocene paleointensities: Thellier experiments on submarine basaltic glass from the East Pacific Rise’, J. Geophys. Res. 98, 17,949-17,964.

    Google Scholar 

  • Potter, D. and Stephenson, A.: 1988, ‘Single-domain particles in rocks and magnetic fabric analysis’, Geophys. Res. Lett. 15(10), 1097-1100.

    Google Scholar 

  • Potter, D.K. and Stephenson, A.: 1990a, ‘Field-impressed anisotropies of magnetic susceptibility and remanence in minerals’, J. Geophys. Res. 95, B10, 15,573-15,588.

    Google Scholar 

  • Potter, D.K. and Stephenson, A.:1990b, ‘Field-impressed magnetic anisotropy in rocks’, Geophys. Res. Lett. 17(12), 2437-2440.

    Google Scholar 

  • Roberts, A.P., Cui, Y., and Verosub, K.L.: 1995, ‘Wasp-waisted hysteresis loops: Mineral magnetic characteristics and discrimination of components in mixed magnetic systems’, J. Geophys. Res. 100, 17,909-17,924.

    Google Scholar 

  • Rochette, R., Jackson, M., and Aubourg, C.: 1992, ‘Rock magnetism and the interpretation of magnetic susceptibility’, Review of geophysics 30, 3, 209-226.

    Google Scholar 

  • Rogers, J., Fox, J.M.W., and Aitken, M.J.: 1979, ‘Magnetic anisotropy in ancient pottery’, Nature 227(5698), 644-646.

    Google Scholar 

  • Sigalas, I., Gangas, N-H.J., and Danon, J.: 1978, ‘Weathering model in paleomagnetic field intensity measurements on ancient fired clays’, Physi. Earth Planet. Inter. 16, 15-19.

    Google Scholar 

  • Schnepp, E.: 1994, ‘Determination of geomagnetic palaeointensities from the Quaternary West Eifel volcanic field, Germany’, Geophys. J. Int. 116, 668-714.

    Google Scholar 

  • Stephenson, A., Sadikun, S., and Porter, D.K.: 1986, ‘A theoretical and experimental comparison of the anisotropies of magnetic susceptibility and remanence in rocks and minerals’, Geophys. J. R. Astr. Soc.84, 185-200.

    Google Scholar 

  • Tarling, D.: 1983, Paleomagnetism, Chapman and Hall, London, New York.

    Google Scholar 

  • Tanaka, H.: 1990, ‘Paleointensity high at 9000 years ago from volcanic rocks in Japan’, J. Geophys. Research 95, B11, 17,517-17,531.

    Google Scholar 

  • Tanaka, H. and Kono, M.: 1991, ‘Preliminary results and reliability of palaeointensity studies on historic and 14C dated Hawaiian lavas’, J. Geomag. Geoelectr. 43, 375-388.

    Google Scholar 

  • Thellier, E. and Thellier, O.: 1959, ‘Sur l'intensite du shamp magnetique terrestre dans le passe historique et geologique’, Ann. Geophysique 15, 285-376.

    Google Scholar 

  • Thomas, N.: 1993, ‘An integrated rock magnetic approach to the selection or rejection of ancient basalt samples for palaeointensity experiments’, Phys. Earth Plan. Inter. 75, 329-342.

    Google Scholar 

  • Van Velzen, A.J. and Zijderveld, J.D.A.: 1992, ‘A method to study alterations of magnetic minerals during thermal demagnetization applied to a fine-grained marine marl (Trubi formation, Sicily)’, Geophys. J. Int. 110, 79-90.

    Google Scholar 

  • Veitch, R.J., Hedley, I.G., and Wagner, J.J.: 1984, ‘An investigation of the intensity of the geomagnetic field during roman times using magnetically anisotropic bricks and tiles’, Arch. Sc. Geneve 37, Fasc.3, 359-373.

    Google Scholar 

  • Xu, S. and Dunlop, D.: 1995, ‘Toward a better understanding of the Lowrie-Fuller test’, J. Geophys. Res. 100, B11, 22,533-22,542.

    Google Scholar 

Download references

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kovacheva, M., Jordanova, N. & Karloukovski, V. Geomagnetic Field Variations as Determined from Bulgarian Archaeomagnetic Data. Part II: The Last 8000 Years. Surveys in Geophysics 19, 431–460 (1998). https://doi.org/10.1023/A:1006502313519

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1006502313519

Navigation