Ferropericlase or magnesiowüstite is a magnesium/ironoxide with the chemical formula (Mg,Fe)O that is interpreted to be one of the main constituents of the Earth's lower mantle together with the silicate perovskite ((Mg,Fe)SiO3), a magnesium/iron silicate with a perovskite structure. Ferropericlase has been found as inclusions in a few natural diamonds. An unusually high iron content in one suite of diamonds has been associated with an origin from the lowermost mantle.[1] Discrete ultralow-velocity zones in the deepest parts of the mantle, near the Earth's core, are thought to be blobs of ferropericlase, as seismic waves are significantly slowed as they pass through them, and ferropericlase is known to have this effect at the high pressures and temperatures found deep within the Earth's mantle.[2] In May 2018, ferropericlase was shown to be anisotropic in specific ways in the high pressures of the lower mantle, and these anisotropies may help seismologists and geologists to confirm whether those ultra-low velocity zones are indeed ferropericlase, by passing seismic waves through them from various different directions and observing the exact amount of change in the velocity of those waves.[3]
Changes in the spin state of electrons in iron in mantle minerals has been studied experimentally in ferropericlase. Samples are subject to the conditions of the lower mantle in a laser-heated diamond anvil cell and the spin-state is measured using synchrotronX-rayspectroscopy. Results indicate that the change from a high to low spin state in iron occurs with increasing depth over a range from 1000 km to 2200 km.[4][5]
Mantle abundanceedit
Ferropericlase (Mg,Fe)O makes up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite(Mg,Fe)SiO3; it also is the major host for iron in the lower mantle.[6] At the bottom of the transition zone of the mantle, the reaction
γ–(Mg,Fe)2[SiO4] ↔ (Mg,Fe)[SiO3] + (Mg,Fe)O
transforms γ-olivine into a mixture of perovskite and ferropericlase and vice versa. In the literature, this mineral phase of the lower mantle is also often called magnesiowüstite.[7]
^Marcondes, Michel L.; Zheng, Fawei; Wentzcovitch, Renata M. (2020-09-25). "Phonon dispersion throughout the iron spin crossover in ferropericlase". Physical Review B. 102 (10): 104112. arXiv:2003.12348. Bibcode:2020PhRvB.102j4112M. doi:10.1103/PhysRevB.102.104112. S2CID 214693280.
^Researchers locate mantle's spin transition zone, leading to clues about earth’s structure 2010-05-27 at the Wayback Machine
ferropericlase, magnesiowüstite, magnesium, iron, oxide, with, chemical, formula, that, interpreted, main, constituents, earth, lower, mantle, together, with, silicate, perovskite, sio3, magnesium, iron, silicate, with, perovskite, structure, been, found, incl. Ferropericlase or magnesiowustite is a magnesium iron oxide with the chemical formula Mg Fe O that is interpreted to be one of the main constituents of the Earth s lower mantle together with the silicate perovskite Mg Fe SiO3 a magnesium iron silicate with a perovskite structure Ferropericlase has been found as inclusions in a few natural diamonds An unusually high iron content in one suite of diamonds has been associated with an origin from the lowermost mantle 1 Discrete ultralow velocity zones in the deepest parts of the mantle near the Earth s core are thought to be blobs of ferropericlase as seismic waves are significantly slowed as they pass through them and ferropericlase is known to have this effect at the high pressures and temperatures found deep within the Earth s mantle 2 In May 2018 ferropericlase was shown to be anisotropic in specific ways in the high pressures of the lower mantle and these anisotropies may help seismologists and geologists to confirm whether those ultra low velocity zones are indeed ferropericlase by passing seismic waves through them from various different directions and observing the exact amount of change in the velocity of those waves 3 Contents 1 Spin transition zone 2 Mantle abundance 3 See also 4 ReferencesSpin transition zone editChanges in the spin state of electrons in iron in mantle minerals has been studied experimentally in ferropericlase Samples are subject to the conditions of the lower mantle in a laser heated diamond anvil cell and the spin state is measured using synchrotron X ray spectroscopy Results indicate that the change from a high to low spin state in iron occurs with increasing depth over a range from 1000 km to 2200 km 4 5 Mantle abundance editFerropericlase Mg Fe O makes up about 20 of the volume of the lower mantle of the Earth which makes it the second most abundant mineral phase in that region after silicate perovskite Mg Fe SiO3 it also is the major host for iron in the lower mantle 6 At the bottom of the transition zone of the mantle the reaction g Mg Fe 2 SiO4 Mg Fe SiO3 Mg Fe O transforms g olivine into a mixture of perovskite and ferropericlase and vice versa In the literature this mineral phase of the lower mantle is also often called magnesiowustite 7 See also editIlmenite Post perovskite Wollastonite CaSiO3 References edit Kopylova M G 2006 Ferropericlase from the lowermost mantle and its geodynamic significance Archived from the original on 2016 03 03 Retrieved 2008 03 18 Strange Blobs Beneath Earth Could Be Remnants of an Ancient Magma Ocean Space com Retrieved 2018 10 01 Finkelstein Gregory J Jackson Jennifer M Said Ayman Alatas Ahmet Leu Bogdan M Sturhahn Wolfgang Toellner Thomas S 18 May 2018 Strongly Anisotropic Magnesiowustite in Earth s Lower Mantle PDF Journal of Geophysical Research Solid Earth 123 6 4740 4750 Bibcode 2018JGRB 123 4740F doi 10 1029 2017jb015349 ISSN 2169 9313 Researchers locate mantle s spin transition zone leading to clues about earth s structure Archived from the original on 2010 05 27 Marcondes Michel L Zheng Fawei Wentzcovitch Renata M 2020 09 25 Phonon dispersion throughout the iron spin crossover in ferropericlase Physical Review B 102 10 104112 arXiv 2003 12348 Bibcode 2020PhRvB 102j4112M doi 10 1103 PhysRevB 102 104112 S2CID 214693280 Researchers locate mantle s spin transition zone leading to clues about earth s structure Archived 2010 05 27 at the Wayback Machine Ferropericlase on Mindat org nbsp This inorganic compound related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Ferropericlase amp oldid 1198284631, wikipedia, wiki, book, books, library,
