MAGNETIC CHARACTERISTICS OF METAMORPHIZED ULTRABASITES OF THE OCEANIC LITHOSPHERE

Authors

  • K. V. Popov Shirshov Institute of Oceanology, Russian Academy of Sciences
  • A. M. Gorodnitskiy Shirshov Institute of Oceanology, Russian Academy of Sciences
  • N. A. Shishkina Shirshov Institute of Oceanology, Russian Academy of Sciences

DOI:

https://doi.org/10.29006/1564-2291.JOR-2019.47(4).7

Keywords:

Serpentinization and metamorphism, natural residual magnetization, magnetic susceptibility, saturation magnetization, ocean magnetic field, deep magnetic anomalies

Abstract

As part of the study of the nature of magnetic anomalies associated with the deep layers of the oceanic crust, a comparative analysis was made of the petromagnetic characteristics of serpentinized mantle ultrabasic samples taken from oceanographic expeditions of the Institute of Oceanology and the Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences in various morphotectonic regions of the World Ocean. The purpose of the work is to obtain information on the composition, concentration, crystallization temperature and structural features of ferromagnetic minerals, which are formed in different conditions of the post-magmatic metamorphism of ultrabasites. Sample collections are divided into three groups. 1. Oceanic peridotites from the rift zones of the mid-ocean ridges and transform faults. 2. Peridotites of the submarine ridge Gorringe, located within the Azoro-Gibraltar zone of faults. 3. Dunites of the Pekulney complex (Chukotka) formed in the island arc system. It has been established that in all selected regions, samples of serpentinized hyperbasites have high values of natural residual magnetization, magnetic susceptibility and saturation magnetization. The highest values of magnetic parameters are the dunites of the Pekulney complex. Estimation of the dependence of the concentration of ferrimagnetic materials C% of the degree of serpentinization of the SS%. showed that it is practically of little significance. The main factors contributing to the increase in the concentration of magnetite are the increased iron content of olivine in ultrabasites and the temperature of metamorphism. The question of the period of formation of magnetites and the stability of their primary residual magnetization requires further study.

References


  1. Bazylev B.A. Allohimicheskij metamorfizm mantijnyh peridotitov iz zony razloma Hejs, Severnaya Atlantika, Petrologiya, 1997, Vol. 5, pp. 362–379.

  2. Bazylev B.A., Ledneva G.V., Kononkova N.N., and Ishivatari A. Vysokobaricheskie ul’tramafity v nizhnekorovyh porodah Pekul’nejskogo kompleksa. Central’naya Chukotka (Highpressure ultramafic rocks in the low-crustal rocks of the Pekulnezhsky complex. Central Chukotka). Petrografiya i mineralogiya. Petrologiya, 2013, Vol. 21, No. 3, pp. 247–276.

  3. Bazylev B.A., Popov K.V., and Shcherbakov V.P. Petrographic features of oceanic peridotites as reflected by their magnetic characteristics. Russian Journal of Earth Sciences, 2002, Vol. 4, No. 3,http://elpub.wdcb.ru/journals/rjes/v04/tje02087/tje02087.htm.

  4. Bazylev B.A., Silant’ev S.A., and Kononkova N.N. Metamorfizm giperbazitov v okeanicheskoj kore (Metamorphism of Hyperabasites in Oceanic Crust). Magmatizm i tektonika okeana (proekt “Litos”), Moscow: Nauka, 1990, pp. 296–318.

  5. Bazylev B.A. and Silant’ev S.A. Geodinamicheskaya interpretaciya subsolidusnoj perekristallizacii mantijnyh shpinelevyh peridotitov. Sredinno-Okeanicheskie hrebty. Petrologiya, 2000, Vol. 8(3), pp. 227–240.

  6. Bolshakov A.S. and Shcherbakova V.V. Termomagnitnyy kriteriy opredeleniya domennoy struktury ferromagnetikov. Izv.AN SSSR. Fizika Zemli, 1979, No. 2, pp. 38–45.

  7. Bonatti E., Lawrence Y.R., and Morandi N. Serpentinization of oceanic peridotites: temperature dependence of mineralogy and boron contents. Earth Planet Sci. Letters, 1984, Vol. 70, pp. 88–94.

  8. Bonnemains D., Carlut J., Escartín J., Mével C., and Andreani M. Magnetic signatures of serpentinization at ophiolite complexes. Geochemistry, Geophysics Geosystems, AGU and the Geochemical Society, 2016, Vol. 17(8), pp. 2969–2986.

  9. Bougault H., Dmitriev L., and Schilling J. Mantle heterogentty from trace elements: MAR triple junction near 14oN. Earth and Planet. Sci. Lett., 1988, Vol. 88, pp. 27–36.

  10. Dosso L., Bougault H., Langmuir C., Bollinger C., Bonnier O., and Etoubleau J. The age and distribution of mantle heterogeneity along the Mid-Atlantic Ridge (31–41оN). Earth Planet. Sci. Letters, 1999, Vol. 170, pp. 269–286.

  11. Dunlop D.J. and Prevot M. Magnetic properties and opaque mineralogy of drilled submarine intrusive rocks. Geophys. J. Roy. Astr., Soc. 69, 1982, pp. 763–802.

  12. Ferré, E.C., Friedman S.A., Martín-Hernández F., Feinberg J.M., Till J.L., Ionov D.A., and Conder J.A. Eight good reasons why the uppermost mantle could be magnetic. Tectonophysics, 2014, pp. 1–10, doi: org/10.1016/j.tecto.2014.01.004.

  13. Gorodnickij A.M. and Shishkina N.A. Obobshchennaya petromagnitnaya model’ okeanicheskoj litosfery. Priroda magnitnyh anomalij i stroenie okeanicheskoj kory. Moskva: VNIRO, 1996, pp. 243–252.

  14. Kashchincev G.L. Glubinnye porody okeanov (Deep ocean rocks). Moscow: Nauka, 1991.

  15. Kimball K.L., Spear F.S., and Dick H.J.B. High-temperature alteration of abyssal ultramafic rocks from the Islas Orcadas fracture zone, South Atlantic. Contrib. Mineral. Petrol., 1985, Vol. 94, pp. 307–320.

  16. Kuznecov YU.A. and Pecherskij D.M. Metodicheskie rekomendacii po izucheniyu petromagnitnyh i magnitnyh svojstv porod vskrytyh svekhglubokimi skvazhinami (Guidelines for the study of petromagnetic and magnetic properties of rocks exposed to svekhkhlubokie wells). Tver’: NPGP «GERS», 1992, 86 p.

  17. Laughton A.S. and Whitmarsh R.B. The Azores-Gibraltar plate boundary, Geodynamics of Iceland and the North Atlantic Area. Reykjavik: NATO Advanced Study institute, 1974, pp. 63–81.

  18. Loz’ko E.E. Serpentinity i gabbroidy razloma Klarion (central’naya chast’ Tihogo okeana) (Clarion serpentinites and gabbroids (central Pacific)). Izvestiya AN SSSR, ser. geolog., 1985, No. 12, pp. 28–42.

  19. Maffione M., Morris A., Plumper O., and van Hinsbergen D.J.J. Magnetic properties of variably serpentinized peridotites and their implication for the evolution of oceanic core complexes. Geochem. Geophys. Geosyst., 2014, Vol. 15, doi:10.1002/ 2013GC004993.

  20. Nazarova E.A., J. Wasilewski P.J., and Dick H.J.B. Magnetic Study of Serpentinized Harzburgites from the Islas Orcadas Fracture Zone. Marine Geophysical Research, 2000, Vol. 21, No. 5, pp. 475–488.

  21. Oufy O., Cannat M., and Hoen H. Magnetic properties of variably serpentinized abyssal peridotites. Journal of geophysical research, 2001, Vol. 107, No. B5, pp. 20–95.

  22. Pecherskiy D.M. and Sokolov D.D. Paleomagnitologiya. petromagnitologiya i geologiya. Slovar. Spravochnik dlya sosedey po spetsialnosti, 2011, 199 p.

  23. Popov K.V., Bazylev B.A., and Shcherbakov V.P. Temperaturnyj interval vozniknoveniya namagnichennosti okeanicheskih shpinelevyh peridotitov (Temperature range of magnetization of oceanic spinel peridotites). Okeanologiya, 2006, Vol. 46, No. 2, pp. 278–289.

  24. Popov K.V., Bazylev B.A., Shcherbakov V.P., and Gapeev A.K. Sopostavlenie magnitnyh i petrologicheskih harakteristik peridoitov hrebta Gorrindzh s peridotitami Sredinnookeanicheskih hrebtov (Comparison of the magnetic and petrological characteristics of the Goridzh ridge peridoites with the peridotites of the Mid-ocean ridges). Okeanologiya, 2011, Vol. 51, No. 1, pp. 162–170.

  25. Popov K.V., Bazylev B.A., Shcherbakov V.P. Tsel’movich V.A., and KononkovaN.N. Thermomagnetic analysis of ultramafic rocks: A case study of dunite from the Pekul’ney Complex, Chukotka, NE Russia. J. Earth Sci., 2015, Vol. 15, ES1003, doi:10.2205/2015ES000547.

  26. Pecherskiy D.M. and Didenko A.N. Paleoaziatskiy okean: petromagnitnaya i paleomagnitnaya informatsiya o ego litosfere. Moscow; IFZ RAN, 1995, 298 p.

  27. Prichard H.M. and Mitchell J.G. K–Ar data for the age and evolution of Gettisburg bank, North Atlantic ocean. Earth and Science Letters, 1979, No. 44, pp. 261–268.

  28. Prinz M., Keil K., Green J.A., Reid A.M., Bonatti E., and Honnorez J. Ultramafic and mafic dredge samples from the equatorial Mid-Atlantic Ridge and fracture zones. J. Geophys. Res., 1976, Vol. 81(23), pp. 4087–4103.

  29. Sack R.O. and Ghiorso M.S. Chromian spinels as petrogenetic indicators: thermodynamics and petrological applications. Am. Mineral, 1991, Vol. 76, pp. 827–847.

  30. Shcherbakov V.P., Lamash B.E., and Shcherbakova V.V. Priroda namagnichennosti gornyh porod okeanicheskoj kory (Nature of the magnetization of the rocks of the oceanic crust). Priroda magnitnyh anomalij i stroenie okeanicheskoj kory, Moscow: VNIRO, 1996, pp. 7–35.

  31. Talwani M., Windish C.C., and Langseth M.G. Reykjanes ridge crest: A detailed geophysical study. J. Geophys. Res., 1971, Vol. 76, pp. 473–517.

  32. Zhiyong Li., Zheng J., Qing Sheng Liu, and Qing Xiong. Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture-zone magnetic anomalies. J. Geophys. Res. Solid Earth, 2017, Vol. 122, pp. 4814–4830, doi:10.1002/017JB014241.

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Published

2019-12-01

Issue

Vol. 47 No. 4 (2019): Journal of Oceanological Research

Section

Marine geology, geophysics and geochemistry

License

Transfer of copyrights occurs on the basis of a license agreement between the Author and Shirshov Institute of Oceanology, RAS

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