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Modelling Relationship Between Bulk Susceptibility and AMS in Rocks Consisting of Two Magnetic Fractions Represented by Ferromagnetic and Paramagnetic Minerals - Implications for Understanding Magnetic Fabrics in Deformed Rocks


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1 AGICO Inc., Jecna 29a, Box 90, CZ-621 00 Brno, Czech Republic
     

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Measurement of Anisotropy of Magnetic Susceptibility (AMS) has become an important tool for Structural Geological analysis in the past few decades. In the past, AMS data have been used for petrofabric analysis of deformed rocks as well as for gauging strain. However, the AMS of some rocks can be carried by both ferromagnetic and paramagnetic minerals. Separating effects of these mineral groups on the rock'sAMS is difficult because of expensive and commercially less available instrumentation. On the other hand, instrumentation is available in most rock magnetic and palaeomagnetic laboratories for resolving bulk susceptibility into ferromagnetic and paramagnetic components. Mathematical modelling was made of the relationship between bulk susceptibility and AMS. If the contribution of the ferromagnetic or the paramagnetic fraction to the rock susceptibility is dominant (let us say higher than 80%), the resultant AMS is relatively near to the AMS of the dominating fraction in all aspects, the degree of AMS, shape parameter and orientation of principal susceptibilities. In the interpretation of the AMS of rocks with dominating one fraction, the resolution of the AMS into paramagnetic and ferromagnetic components is not necessary, the resolution of bulk susceptibility into components is sufficient that can be made using the instrumentation available in most rock magnetic and palaeomagnetic laboratories.

Keywords

Magnetic Anisotropy, Bulk Susceptibility, Ferro- and Para-Magnetic Minerals, Mathematical Modelling.
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  • ARCHANJO, C.J., LAUNEAU, P. and BOUCHEZ, J.L. (1995) Magnetic fabric vs. magnetite and biotite shape fabrics of the magnetitebearing granite pluton of Gamelerias (Northeast Brazil). Phys. Earth Planet. Inter., v.89, pp.63-75.

  • AYDIN, A., FERRE, E.C. and ASLAN, Z. (2007) The magnetic susceptibility of granitic rocks as a proxy for geochemical differentiation: Example from the Saruhan granitoids, NE Turkey. Tectonophysics, v.441, pp.85-95.

  • BLEIL, U. and PETERSEN, N. (1982). Magnetic properties of rocks. In: G. Angenheister (editor), Landolt-Bornstein Numerical Data and Functional Relationships in Science and technology. Springer-Verlag Berlin, pp.366-432.

  • BORRADAILE, G.J. and ALFORD, C. (1987) Relationship between magnetic susceptibility and strain in laboratory experiments. Tectonophysics, v.133, pp.121-135.

  • BORRADAILE, G., KEELER, W., ALFORD, C. and SARVAS, P. (1987) Anisotropy of magnetic susceptibility of some metamorphic minerals. Phys. Earth Planet. Inter., v.48, pp.161-166.

  • BORRADAILE, G.J. and WERNER, T. (1994) Magnetic anisotropy of some phyllosilicates. Tectonophysics, v.235, pp.223-248.

  • BOUCHEZ, J. L. (2000) Anisotropie de susceptibilitE magnEtique et fabrique des granites. C.R. Acad. Sci. Paris, Sciences de la Terre et des planets, v.330, pp.1-14.

  • CIFELLI, F., MATTEI, M., CHADIMA, M., LENSER, S. and HIRT, A.M. (2009). The magnetic fabric in "undeformed clays": AMS and neutron texture analyses from the Rif Chain (Morocco). Tectonophysics, v.466, pp.79-88.

  • COLLINSON, D.W. (1983) Methods in rock magnetism and palaeomagnetism. Techniques and instrumentation. Chapman & Hall, London-New York.

  • DUNLOP, D.J. and OZDEMIR, O. (1997) Rock Magnetism. Fundamentals and frontiers. Cambridge University Press, 573p.

  • FRIEDRICH, D. (1995) Gefugeuntersuchungen an Amfiboliten der BOhmische Masse unter besonderer Berucksichtigung der Anisotropie der magnetischen Suszeptibilitat. Geotektonische Forschungen, v.82, pp.1-118.

  • GREILING, R.O., GRIMMER, J.C., DE WALL, H. and BJORK, L. (2007) Mesoproterozoic dyke swarms in foreland and nappes of the central Scandinavian Caledonides: structure, magnetic fabric, and geochemistry. Geol. Mag., v.144, pp.525-546.

  • HEJTMAN, B. (1957) Systematic petrography of igneous rocks (in Czech). NÈSAV Praha, 363p.

  • HEJTMAN, B. (1962). Petrography of metamorphic rocks (in Czech). NESAV Praha, 539p.

  • HENRY, B. (1983) Interpretation quantitative de l'anisotropie de susceptibilite magnetique. Tectonophysics, v.91, pp.165-177.

  • HENRY, B. and DALY, L. (1983) From qualitative to quantitative magnetic anisotropy analysis: the prospect of finite strain calibration. Tectonophysics, v.98, pp.327-336.

  • HROUDA, F. (1982) Magnetic anisotropy of rocks and its application in geology and geophysics. Geophys. Surv., v.5, pp.37-82.

  • HROUDA, F. (1986) The effect of quartz on the magnetic anisotropy of quartzite. Studia geophys. geod., v.30, pp.39-45.

  • HROUDA, F. (1993) Theoretical models of magnetic anisotropy to strain relationship revisited. Phys. Earth Planet. Inter., v.77, pp.237-249.

  • HROUDA, F. (1994) A technique for the measurement of thermal changes of magnetic susceptibility of weakly magnetic rocks by the CS-2 apparatus and KLY-2 Kappabridge. Geophys. Jour. Int., v.118, pp.604-612.

  • HROUDA, F. (2004) Problems in interpreting AMS parameters in diamagnetic rocks, 49-59. In: F. Martín-Hernández, C.M. Luneburg, C. Aubourg and M. Jackson (Eds) Magnetic Fabric: Methods and Applications. Geol. Soc. London, Spec. Publ., 238p.

  • HROUDA, F. (2007). Magnetic susceptibility, anisotropy. In: D. Gubbins and E. Herrero-Bervera (Eds.), Encyclopedia of Geomagnetism and Paleomagnetism. Springer, pp.546- 560.

  • HROUDA, F. and KAHAN, S. (1991) The magnetic fabric relationship between sedimentary and basement nappes in the High Tatra Mts. (N Slovakia). Jour. Struct. Geol., v.13, pp.431-442.

  • HROUDA, F., JELINEK,V. and ZAPLETAL, K. (1997). Refined technique for susceptibility resolution into ferromagnetic and paramagnetic components based on susceptibility temperaturevariation measurement. Geophys. Jour. Int., v.129, pp.715- 719.

  • HROUDA, F., TABORSKA, S., SCHULMANN, K., JEUEK, J. and DOLEJS, D. (1999). Magnetic fabric and rheology of co-mingled magmas in the Nasavrky Plutonic Complex (E Bohemia): implications for intrusive strain regime and emplacement mechanism. Tectonophysics, v.307, pp.93-111.

  • JELINEK, V. (1981) Characterization of magnetic fabric of rocks. Tectonophysics, v.79, pp.T63-T67.

  • JEUEK, J. and HROUDA, F. (2000) The Relationship Between the Lisle Orientation Tensor and the Susceptibility tensor. Phys. Chem. Earth (A), v.25, pp.469-474.

  • JEUEK, J. and HROUDA, F. (2007) SUSIE: A program for inverse strain estimation from magnetic susceptibility. Computers & Geosciences, v.33, pp.749-759.

  • LAUNEAU, P. and CRUDEN,A.R. (1998) Magmatic fabric acquisition mechanisms in a syenite: results of a combined anisotropy of magnetic susceptibility and image analysis study. Jour. Geoph. Res., v.103, pp.5067-5089.

  • MARTIN-HERNANDEZ, F. and FERRE, E.C. (2007) Separation of paramagnetic and ferromagnetic anisotropies: A review. Jour. Geophys. Res., v.112, B03105, doi: 10.1029/2006JB004340.

  • MARTiN-HERNANDEZ, F. and HIRT, A.M. (2003) The anisotropy of magnetic susceptibility in biotite, muscovite and chlorite single crystals. Tectonophysics, v.367, pp.13-28.

  • MUKHERJI, A., CHAUDHURI, A.K. and MAMTANI, M.A. (2004) Regional scale strain variations in the Banded Iron Formations of eastern India: results from anisotropy of magnetic susceptibility studies. Jour. Struct. Geol., v. 26, pp. 2175-2189.

  • NAGATA, T. (1961) Rock magnetism. Maruzen Tokyo. NYE, J.F. (1957) Physical properties of crystals. Clarendon Press, Oxford.

  • PETRANEK., J. (1963) Petrography of sedimentary rocks (in Czech). NCSAV Praha, 718p.

  • ROCHETTE, P. (1988) Relations entre deformation et metamorphisme alpin dans les schistes noirs helvetiques: l'apport de la fabrique magnetique. Geodin. Acta, v.2, pp.17-24.

  • ROCHETTE, P., JACKSON, J. andAUBOURG, C. (1992) Rock magnetism and the interpretation of anisotrophy of magnetic susceptibility. Reviews of Geophysics, v.30, pp.209-226.

  • ROCHETTE, P., SCAILLET, B., GUILLOT, S., LE FORT, P. and PECHER, A. (1994). Magnetic properties of the High Himalayan leucogranites: structural implications. Earth Planet. Sci. Lett., v.126, pp.217-234.

  • SCHEIDEGGER, A.E. (1965) On the statistics of the orientation of bedding planes, grain axes and similar sedimentological data. U.S. Geol. Surv. Prof. Paper, 525-C, pp.164-167.

  • SEN, K. and MAMTANI, M.A. (2006) Magnetic fabric, shape preferred orientation and regional strain in granitic rocks. Jour. Struct. Geol., v.28, pp.1870-1882.

  • SEN, K., MAJUMDER, S. and MAMTANI, M.A. (2005) Degree of magnetic anisotropy as a strain intensity gauge in ferromagnetic granites. Jour. Geol. Soc. London, v.162, pp.583-586.

  • SYONO, Y. (1960) Magnetic susceptibility of some rock forming silicate minerals such as amphiboles, biotites, cordierites and garnets. Jour. Geomagn. Geoelectr., v.11. pp.85-93.

  • UYEDA S., FULLER M.D., BELSHE J.C. and GIRDLER, R.W. (1963) Anisotropy of magnetic susceptibility of rocks and minerals. Jour. Geophys. Res., v.68, pp.279-292.

  • ZAPLETAL., K. (1985) Mean susceptibility and magnetic anisotropy of biotite (in Czech). In: F. Hrouda, V. Jelinek and K. Zapletal (Eds.), The use of magnetic properties of rocks in ore and oil geophysics. Unpublished report of Geofyzika, n.p., Brno, pp.54-75.

  • ZAPLETAL, K. (1990) Low-field susceptibility anisotropy of some biotite crystals. Phys. Earth Planet. Inter., v.63, pp.85-97.


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  • Modelling Relationship Between Bulk Susceptibility and AMS in Rocks Consisting of Two Magnetic Fractions Represented by Ferromagnetic and Paramagnetic Minerals - Implications for Understanding Magnetic Fabrics in Deformed Rocks

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Authors

Frantisek Hrouda
AGICO Inc., Jecna 29a, Box 90, CZ-621 00 Brno, Czech Republic

Abstract


Measurement of Anisotropy of Magnetic Susceptibility (AMS) has become an important tool for Structural Geological analysis in the past few decades. In the past, AMS data have been used for petrofabric analysis of deformed rocks as well as for gauging strain. However, the AMS of some rocks can be carried by both ferromagnetic and paramagnetic minerals. Separating effects of these mineral groups on the rock'sAMS is difficult because of expensive and commercially less available instrumentation. On the other hand, instrumentation is available in most rock magnetic and palaeomagnetic laboratories for resolving bulk susceptibility into ferromagnetic and paramagnetic components. Mathematical modelling was made of the relationship between bulk susceptibility and AMS. If the contribution of the ferromagnetic or the paramagnetic fraction to the rock susceptibility is dominant (let us say higher than 80%), the resultant AMS is relatively near to the AMS of the dominating fraction in all aspects, the degree of AMS, shape parameter and orientation of principal susceptibilities. In the interpretation of the AMS of rocks with dominating one fraction, the resolution of the AMS into paramagnetic and ferromagnetic components is not necessary, the resolution of bulk susceptibility into components is sufficient that can be made using the instrumentation available in most rock magnetic and palaeomagnetic laboratories.

Keywords


Magnetic Anisotropy, Bulk Susceptibility, Ferro- and Para-Magnetic Minerals, Mathematical Modelling.

References