Abstract
Since the 1970s, ferromagnetic minerals were believed to be absent in the Earth’s mantle and, even if present, the temperatures were considered too high for such phases to carry magnetic remanence. However, new experimental data, measurements on mantle xenoliths and an improved understanding of long-wavelength features in aeromagnetic data require that the magnetization of the mantle be revisited. In this Review, we examine mantle magnetism through the xenolith record, evaluate the latest experimental advances, assess detection methods of deep-seated mantle sources and identify salient, unsolved questions about magnetic sources in the Earth’s mantle. Critically, magnetic data on a worldwide collection of mantle xenoliths have revealed that pure magnetite is common in the uppermost mantle (<150 km), particularly in subduction zones and cratons. Furthermore, experiments on haematite and its polymorphs suggest that they could carry a magnetic remanence down to ~600 km, for example, in cold, subducted slabs. Finally, modern spectral analysis of aeromagnetic data confirms that a magnetized layer is present below the crust–mantle boundary in multiple tectonic settings. Future work needs to explore the magnetic minerals in the deepest available mantle xenoliths (150–660 km), in conjunction with experiments on mantle materials at pressures corresponding to these depths.
Key points
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The old view of a globally non-magnetic mantle should be revisited.
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Some iron oxides are stable and carry a magnetic remanence down to 660 km.
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Magnetite is ubiquitous in upper mantle xenoliths.
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New spectral methods show that some magnetic sources lie within the mantle.
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Low-geotherm regions are prime locations for mantle magnetic sources.
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References
Aki, K. & Richards, G. Quantitative Seismology 2nd edn 700 pp (University Science Books, 2002).
Kono, M. (ed.) Treatise on Geophysics Vol. 5. Geomagnetism 589 pp (Elsevier, 2009).
Pail, R. et al. First GOCE gravity field models derived by three different approaches. J. Geod. 85, 819–843 (2011).
Stechschulte, V. C. The Japanese earthquake of March 29, 1928, and the problem of depth of focus. Bull. Seismol. Soc. Am. 22, 81–137 (1932).
Bercovici, D. & Karato, S. Whole-mantle convection and the transition-zone water filter. Nature 425, 39–44 (2003).
Vine, F. J. & Matthews, D. H. Magnetic anomalies over oceanic ridges. Nature 199, 947–949 (1963).
Bloxham, J. Sensitivity of the geomagnetic axial dipole to thermal core–mantle interactions. Nature 405, 63–65 (2000).
Merrill, R. T. & McFadden, L. The geomagnetic axial dipole field assumption. Phys. Earth Planet. Inter. 139, 171–185 (2003).
Finlay, C. C. et al. International Geomagnetic Reference Field: the eleventh generation. Geophys. J. Int. 183, 1216–1230 (2010).
Butler, R. F. Paleomagnetism 319 pp (Blackwell Scientific Publications, 1992).
Tauxe, L. Paleomagnetic Principles and Practice 314 pp (Springer, 2006).
Katsura, T., Yoneda, A., Yamazaki, D., Yoshino, T. & Ito, E. Adiabatic temperature profile in the mantle. Phys. Earth Planet. Inter. 183, 212–218 (2010).
Nagata, T. Rock Magnetism 350 pp (Maruzen, 1961).
O’Reilly, W. Rock and Mineral Magnetism 232 pp (Blackie & Son Limited, 1984).
Tauxe, L. Paleomagnetic Principles and Practice. Modern Approaches in Geophysics 312 pp (Kluwer, 1998).
Gilder, S. A., LeGoff, M., Chervin, J.-C. & Peyronneau, J. Magnetic properties of single and multi-domain magnetite under pressures from 0 to 6 GPa. Geophys. Res. Lett. 31, L10612 (2004).
Gilder, S. A. & Le Goff, M. Systematic pressure enhancement of titanomagnetite magnetization. Geophys. Res. Lett. 35, L10302 (2008).
Kupenko, I. et al. Magnetism in cold subducting slabs at mantle transition zone depths. Nature 570, 102–106 (2019).
Haggerty, S. E. & Sautter, V. Ultradeep (greater than 300 kilometers), ultramafic upper mantle xenoliths. Science 248, 993–996 (1990).
Abu-Aljarayesh, I., Mahmood, S. & Nasir, S. Magnetic study on lower crustal and upper mantle xenoliths from northeast Jordan. Abhath Al-Yarmouk. Pure Sci. Eng. 2, 41–54 (1993).
Collerson, K. D., Hapugoda, S., Kamber, B. S. & Williams, Q. Rocks from the mantle transition zone: Majorite-bearing xenoliths from Malaita, Southwest Pacific. Science 288, 1215–1223 (2000).
Friedman, S. A. et al. Craton vs. rift uppermost mantle contributions to magnetic anomalies in the United States interior. Tectonophysics 624–625, 15–23 (2014).
Martín-Hernández, F., Ferré, E. C. & Friedman, S. A. Remanent magnetization in fresh xenoliths derived from combined demagnetization experiments: Magnetic mineralogy, origin and implications for mantle sources of magnetic anomalies. Tectonophysics 624–625, 24–31 (2014).
Blakely, R. J., Brocher, T. M. & Wells, R. E. Subduction-zone magnetic anomalies and implications for hydrated forearc mantle. Geology 33, 445–448 (2005).
Bilim, F., Akay, T., Aydemir, A. & Kosaroglu, S. Curie point depth, heat-flow and radiogenic heat production deduced from the spectral analysis of the aeromagnetic data for geothermal investigation on the Menderes Massif and the Aegean Region, western Turkey. Geothermics 60, 44–57 (2016).
Wasilewski, J., Thomas, H. H. & Mayhew, M. A. The Moho as a magnetic boundary. Geophys. Res. Lett. 6, 541–544 (1979).
Shive, N. The Ivrea Zone and lower crustal magnetization. Tectonophysics 182, 161–167 (1990).
Wasilewski, J. & Mayhew, M. A. The Moho as a magnetic boundary revisited. Geophys. Res. Lett. 19, 2259–2262 (1992).
Chopping, R. & Kennett, B. L. N. Maximum depth of magnetisation of Australia, its uncertainty, and implications for Curie depth. GeoResJ 7, 70–77 (2015).
Gailler, L.-S., Lénat, J.-F. & Blakely, R. J. Depth to Curie temperature or bottom of the magnetic sources in the volcanic zone of la Réunion hot spot. J. Volcanol. Geotherm. Res. 324, 169–178 (2016).
Idárraga-García, J. & Vargas, C. A. Depth to the bottom of magnetic layer in South America and its relationship to Curie isotherm, Moho depth and seismicity behavior. Geod. Geodyn. 9, 93–107 (2018).
Wang, J. & Li, C.-F. Crustal magmatism and lithospheric geothermal state of western North America and their implications for a magnetic mantle. Tectonophysics 638, 112–125 (2015).
van der Meijde, M. & Pail, R. Impact of uncertainties of GOCE gravity model on crustal thickness estimates. Geophys. J. Int. 221, 1226–1231 (2020).
Frisch, T. Alteration of chrome spinel in a dunite nodule from Lanzarote, Canary Islands. Lithos 4, 83–91 (1971).
Evans, B. W. & Frost, B. R. Chrome-spine1 in progressive metamorphism — A preliminary analysis. Geochim. Cosmochim. Acta 39, 959–972 (1975).
Bliss, N. W. & Maclean, W. H. The paragenesis of zoned chromite from central Manitoba. Geochim. Cosmochim. Acta 39, 973–990 (1976).
Hess, H. H. in Petrologic Studies: A Volume in Honor of A. F. Buddington (eds Engel, A. E. J., James, H. L. & Leonard, B. F.) 599–620 (Geological Society of London, 1962).
Christensen, N. I. The abundance of serpentinites in the oceanic crust. J. Geol. 80, 709–719 (1972).
Faccenda, M., Gerya, T. V. & Burlini, L. Deep slab hydration induced by bending-related variations in tectonic pressure. Nat. Geosci. 2, 790–793 (2009).
Abily, B., Ceuleneer, G. & Launeau, P. Synmagmatic normal faulting in the lower oceanic crust: Evidence from the Oman ophiolite. Geology 39, 391–394 (2011).
Detrick, R. S., White, R. S. & Purdy, G. M. Crustal structure of North Atlantic fracture zones. Rev. Geophys. 31, 439–458 (1993).
Parkinson, C. Emplacement of the East Sulawesi Ophiolite: evidence from subophiolite metamorphic rocks. J. Asian Earth Sci. 16, 13–28 (1998).
Arkani-Hamed, J. Remanent magnetization of the oceanic upper mantle. Geophys. Res. Lett. 15, 48–51 (1988).
Tivey, M. et al. A submersible study of the western intersection of the Mid-Atlantic ridge and Kane fracture zone (WMARK). Mar. Geophys. Res. 20, 195–218 (1998).
Tominaga, M. et al. Characterization of the in situ magnetic architecture of oceanic crust (Hess Deep) using near-source vector magnetic data. J. Geophys. Res. Solid Earth 121, 4130–4146 (2016).
Haggerty, S. E. & Toft, B. Native iron in the continental lower crust: petrological and geophysical implications. Science 229, 647–649 (1985).
Toft, B. & Haggerty, S. E. Limiting depth of magnetization in cratonic lithosphere. Geophys. Res. Lett. 15, 530–533 (1988).
Pechersky, D. M. & Genshaft, Y. S. Petromagnetism of the continental lithosphere and the origin of regional magnetic anomalies: A review. Russian J. Earth Sci. 3, 1–36 (2001).
Pechersky, D. M. & Genshaft, Y. S. Petromagnetism of the continental crust: A summary of 20th century research. Phys. Solid Earth 38, 4–36 (2002).
Canil, D., Virgo, D. & Scarfe, C. M. Oxidation state of mantle xenoliths from British Columbia, Canada. Contrib. Mineral. Petrol. 104, 453–462 (1990).
Kiseeva, E. S. et al. Oxidized iron in garnets from the mantle transition zone. Nat. Geosci. 11, 144–147 (2018).
Warner, R. D. & Wasilewski, J. Magnetic petrology of lower crust and upper mantle xenoliths from McMurdo Sound, Antarctica. Tectonophysics 249, 69–92 (1995).
Warner, R. D. & Wasilewski, J. Magnetic petrology of arc xenoliths from Japan and Aleutian Islands. J. Geophys. Res. 102, 20225–20243 (1997).
Alva-Valdivia, L. M. et al. Paleomagnetic and magnetic fabric studies of the San Gaspar Ignimbrite, western Mexico—constraints on emplacement mode and source vents. J. Volcanol. Geotherm. Res. 147, 68–80 (2005).
Pearson, D. G., Canil, D. & Shirey, S. B. in Treatise on Geochemistry Vol. 2 (ed. Carlson, R. W.) 171–276 (Elsevier, 2003).
Al-Malabeh, A., El-Hasan, T. & Lataifeh, M. Geochemical, petrographic and magnetic characteristics of spinel lherzolite mantle xenoliths from Jabal Remah volcano, Jordan. Am. J. Appl. Sci. 6, 1308–1312 (2009).
Ferré, E. C. et al. The magnetism of mantle xenoliths and potential implications for sub-Moho magnetic sources. Geophys. Res. Lett. 40, 105–110 (2013).
Ferré, E. C. et al. Eight good reasons why the uppermost mantle could be magnetic. Tectonophysics 624–625, 3–14 (2014).
Li, Z., Zheng, J., Zeng, Q., Liu, Q. & Griffin, W. L. Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust. J. Geophys. Res. Solid Earth 119, 806–821 (2014).
Knafelc, J. et al. The effect of oxidation on the mineralogy and magnetic properties of olivine. Am. Mineral. 104, 694–702 (2019).
Brewster, D. & O’Reilly, W. Magnetic properties of synthetic analogues of the altered olivines of igneous rocks. Geophys. J. 95, 421–432 (1988).
Nixon, H. (ed.) Mantle Xenoliths 844 pp (Wiley, 1987).
Carlson, R. W. The Mantle and Core 608 pp (Elsevier, 2007).
Demouchy, S., Jacobsen, S. D., Gaillard, F. & Stern, C. R. Rapid magma ascent recorded by water diffusion profiles in mantle olivine. Geology 34, 429–432 (2006).
Peslier, A. H., Bizimis, M. & Matney, M. Water disequilibrium in olivines from Hawaiian peridotites: Recent metasomatism, H diffusion and magma ascent rates. Geochim. Cosmochim. Acta 154, 98–117 (2015).
Sen, G. & Jones, R. E. Exsolved silicate and oxide phases from clinopyroxenes in a single Hawaiian xenolith: Implications for oxidation state of the Hawaiian upper mantle. Geology 16, 69–72 (1988).
Drury, M. R. & van Roermund, H. L. M. Metasomatic origin for Fe-Ti-rich multiphase inclusions in olivine from kimberlite xenoliths. Geology 16, 1035–1038 (1988).
Drury, M. R. & van Roermund, H. L. M. Reply to comment by R.L. Hervig on “Metasomatic origin for Fe-Ti-rich multiphase inclusions in olivine from kimberlite xenoliths”. Geology 17, 676–677 (1989).
Hervig, R. L. Comment on “Metasomatic origin for Fe-Ti-rich multiphase inclusions in olivine from kimberlite xenoliths”. Geology 17, 675–676 (1989).
Neal, C. R., Haggerty, S. E. & Sautteran, V. “Majorite” and “silicate perovskite” mineral compositions in xenoliths from Malaita. Science 292, 1015 (2001).
Alard, O. et al. Volatile-rich metasomatism in Montferrier xenoliths (Southern France): Implications for the abundances of chalcophile and highly siderophile elements in the subcontinental mantle. J. Petrol. 52, 2009–2045 (2001).
Samara, G. A. & Giardini, A. A. Effect of pressure on the Néel temperature of magnetite. Phys. Rev. 186, 577–580 (1969).
Schult, A. Effect of pressure on the Curie temperature of titanomagnetites [(1 − x)·Fe3O4 − x·TiFe2O4]. Earth Planet. Sci. Lett. 10, 81–86 (1970).
Volk, M. W. R. & Feinberg, J. M. Domain state and temperature dependence of pressure remanent magnetization in synthetic magnetite: implications for crustal remagnetization. Geochem. Geophys. Geosyst. 20, 2473–2483 (2019).
Idoko, C. M., Conder, J. A., Ferré, E. C. & Filiberto, J. The potential contribution to long wavelength magnetic anomalies from the lithospheric mantle. Phys. Earth Planet. Inter. 292, 21–28 (2019).
Facer, J., Downes, H. & Beard, A. In situ serpentinization and hydrous fluid metasomatism in spinel dunite xenoliths from the Bearpaw Mountains, Montana, USA. J. Petrol. 50, 1443–1475 (2009).
Hall, D. H. Long-wavelength aeromagnetic anomalies and deep crustal magnetization in Manitoba and northwestern Ontario, Canada. J. Geophys. 40, 403–430 (1974).
Krutikhovskaya, Z. & Pashkevich, I. Long-wavelength magnetic anomalies as a source of information about deep crustal structure. J. Geophys. 46, 301–317 (1979).
Dunlop, D. J. & Kletetschka, G. Multidomain hematite: a source of planetary magnetic anomalies? Geophys. Res. Lett. 28, 3345–3348 (2001).
Gilder, S. A. & LeGoff, M. in Advances in High-Pressure Technology for Geophysical Applications (eds Chen, J., Wang, Y., Duffy, T. S., Shen, G. & Dobrzhinetskaya, L. F.) 315–335 (Elsevier, 2005).
Jackson, M., Moskowitz, B., Rosenbaum, J. & Kissel, C. Field-dependence of AC susceptibility in titanomagnetites. Earth Planet. Sci. Lett. 157, 129–139 (1998).
Dunlop, D. J. & Özdemir, Ö. Rock Magnetism. Fundamentals and Frontiers. Cambridge Studies in Magnetism 573 pp (Cambridge Univ. Press, 1997).
Hunt, C. P., Moskowitz, B. M. & Banerjee, S. K. in Rock Physics & Phase Relations: A Handbook of Physical Constants (ed. Ahrens, T. J.) 189–204 (American Geophysical Union, 1995).
Özdemir, Ö. & Dunlop, D. J. Hysteresis and coercivity of hematite. J. Geophys. Res. Solid Earth 119, 2582–2594 (2014).
Martín-Hernández, F. & García-Hernández, M. M. Magnetic properties and anisotropy constant of goethite single crystals at saturating high fields. Geophys. J. Int. 181, 756–761 (2010).
Woodland, A. B., Frost, D. J., Trots, D. M., Klimm, K. & Mezouar, M. In situ observation of the breakdown of magnetite (Fe3O4) to Fe4O5 and hematite at high pressures and temperatures. Am. Mineral. 97, 1808–1811 (2012).
Uenver-Thiele, L., Woodland, A. B., Seitz, H.-M., Downes, H. & Altherr, R. Metasomatic processes revealed by trace element and redox signatures of the lithospheric mantle beneath the Massif Central, France. J. Petrol. 58, 395–422 (2017).
Ovsyannikov, S. V. et al. Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation. Nat. Chem. 8, 501–508 (2016).
Spector, A. & Grant, F. S. Statistical models for interpreting aeromagnetic data. Geophysics 35, 293–302 (1970).
Bhattacharyya, B. K. & Leu, L.-K. Analysis of magnetic anomalies over Yellowstone National Park: mapping of Curie point isothermal surface for geothermal reconnaissance. J. Geophys. Res. 80, 4461–4465 (1975).
Bhattacharyya, B. K. & Leu, L. Spectral analysis of gravity and magnetic anomalies due to rectangular prismatic bodies. Geophysics 42, 41–50 (1977).
Okubo, Y., Graf, R. J., Hansen, R. O., Ogawa, K. & Tsu, H. Curie-point depths of the island of Kyushu and surrounding areas, Japan. Geophysics 50, 481–494 (1985).
Ravat, D. in Encyclopedia of Geomagnetism and Paleomagnetism (eds Gubbins D. & Herrero-Bervera E.) 140–144 (Springer, 2007).
Ravat, D., Whaler, K. A., Pilkington, M., Sabaka, T. & Purucker, M. Compatibility of high-altitude aeromagnetic and satellite-altitude magnetic anomalies over Canada. Geophysics 67, 546–554 (2002).
Langel, R. A. & Hinze, W. J. The Magnetic Field of the Earth’s Lithosphere: The Satellite Perspective 450 pp (Cambridge Univ. Press, 1998).
Sabaka, T. J., Olsen, N. & Langel, R. A. A comprehensive model of the quiet-time, near-Earth magnetic field: phase 3. Geophys. J. Int. 151, 32–68 (2002).
Ravat, D. et al. A preliminary, full spectrum, magnetic anomaly grid of the United States with improved long wavelengths for studying continental dynamics: A website for distribution of data. Open-File Report 2009-1258 https://doi.org/10.3133/ofr20091258 (2009).
Minty, B. R. S., Milligan, R., Luyendyk, T. & Mackey, T. Merging airborne magnetic surveys into continental‐scale compilations. Geophysics 68, 988–995 (2003).
Milligan, P., Minty, B., Richardson, M. & Franklin, R. The Australia-wide airborne geophysical survey - accurate continental magnetic coverage. ASEG Ext. Abstr. 2009, 1–9 (2009).
Gregotski, M. E., Jensen, O. & Arkani-Hamed, J. Fractal stochastic modeling of aeromagnetic data. Geophysics 56, 1706–1715 (1991).
Pilkington, M. & Todoeschuck, J. P. Fractal magnetization of continental crust. Geophys. Res. Lett. 20, 627–630 (1993).
Maus, S. & Dimri, V. Scaling properties of potential fields due to scaling sources. Geophys. Res. Lett. 21, 891–894 (1994).
Maus, S. & Dimri, V. Potential field power spectrum inversion for scaling geology. J. Geophys. Res. Solid Earth 100, 12605–12616 (1995).
Maus, S. & Dimri, V. Depth estimation from the scaling power spectrum of potential fields? Geophys. J. Int. 124, 113–120 (1996).
Fedi, M., Quarta, T. & De Santis, A. Inherent power-law behavior of magnetic field power spectra from a Spector and Grant ensemble. Geophysics 62, 1143–1150 (1997).
Bansal, A. R., Gabriel, G., Dimri, V. P. & Krawczyk, C. M. Estimation of depth to the bottom of magnetic sources by a modified centroid method for fractal distribution of sources: An application to aeromagnetic data in Germany. Geophysics 76, L11–L22 (2011).
Maus, S., Gordon, D. & Fairhead, D. Curie-temperature depth estimation using a self-similar magnetization model. Geophys. J. Int. 129, 163–168 (1997).
Maus, S. et al. EMAG2: A 2–arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements. Geochem. Geophys. Geosyst. 10, Q08005 (2009).
Bouligand, C., Glen, J. M. G. & Blakely, R. J. Mapping Curie temperature depth in the western United States with a fractal model for crustal magnetization. J. Geophys. Res. 114, B11104 (2009).
Blakely, R. J. Curie temperature isotherm analysis and tectonic implications of aeromagnetic data from Nevada. J. Geophys. Res. Solid Earth 93, 11817–11832 (1988).
Ross, H. E., Blakely, R. J. & Zoback, M. D. Testing the use of aeromagnetic data for the determination of Curie depth in California. Geophysics 71, 51–59 (2006).
Salem, A. et al. Depth to Curie temperature across the central Red Sea from magnetic data using the de-fractal method. Tectonophysics 624-625, 75–86 (2014).
Ravat, D., Morgan, P. & Lowry, A. R. Geotherms from the temperature-depth–constrained solutions of 1-D steady-state heat-flow equation. Geosphere 12, 1187–1197 (2016).
Dunlop, D. J., Özdemir, Ö. & Costanzo-Alvarez, Magnetic properties of rocks of the Kapuskasing uplift (Ontario, Canada) and origin of long-wavelength magnetic anomalies. Geophys. J. Int. 183, 645–658 (2010).
Pilkington, M. & Percival, J. A. Crustal magnetization and long-wavelength aeromagnetic anomalies of the Minto block, Quebec. J. Geophys. Res. Solid Earth 104, 7513–7526 (1999).
Lévy, F., Jaupart, C., Mareschal, J. C., Bienfait, G. & Limare, A. Low heat flux and large variations of lithospheric thickness in the Canadian Shield. J. Geophys. Res. 115, B06404 (2010).
Chulick, G. S. & Mooney, W. D. Seismic structure of the crust and uppermost mantle of North America and adjacent oceanic basins: a synthesis. Bull. Seismol. Soc. Am. 92, 2478–2492 (2002).
Shapiro, N. M., Ritzwoller, M. H., Mareschal, J. C. & Jaupart, C. Lithospheric structure of the Canadian Shield inferred from inversion of surface-wave dispersion with thermodynamic a priori constraints. Geol. Soc. London Spec. Publ. 239, 175–194 (2004).
Vervelidou, F. & Thébault, E. Global maps of the magnetic thickness and magnetization of the Earth’s lithosphere. Earth Planets Space 67, 173 (2015).
Kennett, B. L. N., Salmon, M., Saygin, E. & Group, A. W. AusMoho: the variation of Moho depth in Australia. Geophys. J. Int. 187, 946–958 (2011).
Salmon, M., Kennett, B. L. N., Stern, T. & Aitken, A. R. A. The Moho in Australia and New Zealand. Tectonophysics 609, 288–298 (2013).
Arkani-Hamed, J. & Strangway, D. W. An interpretation of magnetic signatures of subduction zones detected by MAGSAT. Tectonophysics 133, 45–55 (1987).
Finn, C. Aeromagnetic evidence for a buried Early Cretaceous magmatic arc, northeast Japan. J. Geophys. Res. Solid Earth 99, 22165–22185 (1994).
Campos-Enríquez, J. O., Espinosa-Cardeña, J. M. & Oksum, E. Subduction control on the curie isotherm around the Pacific-North America plate boundary in northwestern Mexico (Gulf of California). Preliminary results. J. Volcanol. Geotherm. Res. 375, 1–17 (2019).
Arkani-Hamed, J. & Strangway, D. W. Intermediate-scale magnetic anomalies of the Earth. Geophysics 50, 2817–2830 (1985).
Clark, S. C., Frey, H. & Thomas, H. H. Satellite magnetic anomalies over subduction zones: The Aleutian Arc anomaly. Geophys. Res. Lett. 12, 41–44 (1985).
Schlinger, C. M. Magnetization of lower crust and interpretation of regional magnetic anomalies: example from Lofoten and Vesterålen, Norway. J. Geophys. Res. Solid Earth 90, 11484–11504 (1985).
Williams, S. E. & Gubbins, D. Origin of long-wavelength magnetic anomalies at subduction zones. J. Geophys. Res. Solid Earth 124, 9457–9473 (2019).
Saad, A. H. Magnetic properties of ultramafic rocks from Red Mountain, California. Geophysics 34, 974–987 (1969).
Wasilewski, J. in Mantle Xenoliths (ed. Nixon, P. H.) 577–588 (Wiley, 1987).
Klein, F. et al. Magnetite in seafloor serpentinite — Some like it hot. Geology 42, 135–138 (2014).
Lécuyer, C. & Ricard, Y. Long-term fluxes and budget of ferric iron: implication for the redox states of the Earth’s mantle and atmosphere. Earth Planet. Sci. Lett. 165, 197–211 (1999).
Dobson, D. P. & Brodholt, J. P. Subducted banded iron formations as a source of ultralow-velocity zones at the core–mantle boundary. Nature 434, 371–374 (2005).
Bykova, E. et al. Structural complexity of simple Fe2O3 at high pressures and temperatures. Nat. Commun. 7, 10661 (2016).
Fukao, Y., Obayashi, M. & Nakakuki, T. Stagnant slab: a review. Annu. Rev. Earth Planet. Sci. 37, 19–46 (2009).
Gubbins, D. & Herrero-Bervera, E. (eds) Encyclopedia of Geomagnetism and Paleomagnetism 250 (Springer, 2007).
Kozlenko, D. P. et al. Magnetic and electronic properties of magnetite across the high pressure anomaly. Sci. Rep. 9, 4464 (2019).
Xu, W., Machavariani, G. Y., Rozenberg, G. K. & Pasternak, M. Mössbauer and resistivity studies of the magnetic and electronic properties of the high-pressure phase of Fe3O4. Phys. Rev. B 70, 174106 (2004).
Hamada, M. et al. Magnetic and spin transitions in wüstite: A synchrotron Mössbauer spectroscopic study. Phys. Rev. B 93, 155165 (2016).
Hu, Q. et al. Dehydrogenation of goethite in Earth’s deep lower mantle. Proc. Natl Acad. Sci. USA 114, 1498–1501 (2017).
Ishii, T., Uenver-Thiele, L., Woodland, A. B., Alig, E. & Boffa Ballaran, T. Synthesis and crystal structure of Mg-bearing Fe9O11: New insight in the complexity of Fe-Mg oxides at conditions of the deep upper mantle. Am. Mineral. 103, 1873–1876 (2018).
Koemets, E. et al. FeOOH instability at the lower mantle conditions. Preprint at arXiv https://arxiv.org/abs/1908.02114 (2019).
Lavina, B. et al. Discovery of the recoverable high-pressure iron oxide Fe4O5. Proc. Natl Acad. Sci. USA 108, 17281–17285 (2011).
Lavina, B. & Meng, Y. Unraveling the complexity of iron oxides at high pressure and temperature: Synthesis of Fe5O6. Sci. Adv. 1, e1400260 (2015).
Sinmyo, R. et al. Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure. Sci. Rep. 6, 32852 (2016).
Ouabego, M. et al. Rock magnetic investigation of possible sources of the Bangui magnetic anomaly. Phys. Earth Planet. Inter. 224, 11–20 (2013).
Launay, N., Quesnel, Y., Rochette, P. & Demory, F. Iron formations as the source of the West African magnetic crustal anomaly. Front. Earth Sci. 6, 32 (2018).
McEnroe, S. A., Robinson, P., Church, N. & Purucker, M. Magnetism at depth: A view from an ancient continental subduction and collision zone. Geochem. Geophys. Geosyst. 19, 1123–1147 (2018).
Olsen, N., Ravat, D., Finlay, C. C. & Kother, L. K. LCS-1: A high-resolution global model of the lithospheric magnetic field derived from CHAMP and Swarm satellite observations. Geophys. J. Int. 211, 1461–1477 (2017).
Launay, N. et al. Thermoremanence acquisition and demagnetization for titanomagnetite under lithospheric pressures. Geophys. Res. Lett. 44, 4839–4845 (2017).
Acknowledgements
This work was supported by the National Science Foundation (grants EAR-0521558 and EAR-1345105 to E.C.F. and EAR-1246921 to D.R.), the National Aeronautics and Space Administration (grants NNX16AN51G and 80NSSC19K0014 to D.R.) and internal funding from the University of Münster.
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Related links
Swarm Anomaly Model: https://www.spacecenter.dk/files/magnetic-models/LCS-1/
Swarm Data Access: https://earth.esa.int/web/guest/swarm/data-access
Supplementary information
Glossary
- Curie temperature
-
Temperature above which magnetization is randomized and destroyed, resulting in the material becoming paramagnetic.
- Thermoremanent magnetization
-
Permanent or remanent magnetization acquired by a ferromagnetic mineral (sensu lato) when cooled through its blocking temperature in the presence of a DC magnetic field, most commonly, the Earth’s magnetic field.
- Blocking temperatures
-
Below a set temperature, the magnetic moments become blocked, owing to the lower thermal energy.
- Mantle xenoliths
-
Deep-seated fragments of the mantle that ascend to the surface in basaltic or kimberlitic magma.
- Curie depth
-
The depth below the Earth’s surface where ferrimagnetic and ferromagnetic minerals abruptly lose their spontaneous magnetization as a result of exceeding their Curie temperature.
- Serpentinization
-
Geochemical reaction of peridotite with aqueous fluids to form serpentine.
- Verwey transition
-
Magnetic-phase transition shown by magnetite (Fe3O4) at Tv ~120 K (at ambient pressure); upon heating, magnetite gradually transforms from a crystallographic monoclinic into an inverse spinel structure.
- Alt-S%
-
Quantifies the degree of sulfide alteration; the total Fe-hydroxide area divided by the total sulfide area (including Fe-hydroxide).
- Loss on ignition
-
High-temperature (~1,000 °C) heating experiment in inert atmosphere or vacuum designed to quantify the percentage of volatile elements in a rock.
- Low-field magnetic susceptibility
-
Slope of the induced magnetization versus applied field curve in magnetic hysteresis when the applied field is sufficiently low to allow reversible magnetization.
- Saturation remanent magnetization
-
Maximum remanent magnetization that can be reached in a high applied field experiment.
- Magnetic coercivity
-
Magnetic intensity required to reduce the magnetization to zero in a fully magnetized specimen.
- Fourier amplitude spectrum
-
Amplitude of each wavelength for a spatial or time variation, which is arranged according to their wavelength, where both wavelengths and amplitudes are obtained through Fourier analysis.
- De-fractaling
-
Removal of power law (or fractal) characteristics from an observed spectra.
- De-fractaled amplitude spectra
-
Amplitude spectrum of magnetic anomalies where the power law dependence is removed.
- Fractal magnetization
-
Fractal relationship of the magnetization distribution.
- Fractal parameter
-
The exponent associated with the power law that governs the spatial characteristics of magnetization or magnetic anomalies.
- Cratons
-
Large, geologically stable regions in continental areas that are typically considered to be tectonically inactive.
- Bouguer gravity anomaly
-
The gravity anomaly corrected for the height of the measurement and the influence of the underlying topography.
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Ferré, E.C., Kupenko, I., Martín-Hernández, F. et al. Magnetic sources in the Earth’s mantle. Nat Rev Earth Environ 2, 59–69 (2021). https://doi.org/10.1038/s43017-020-00107-x
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DOI: https://doi.org/10.1038/s43017-020-00107-x
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