1
|
Cao Z, Guo Z, Li C, Zhao S, Li Y, He Q, Wen Y, Xiao Z, Li X, Xiao L, Li L, Wang J, Liu J. Submicroscopic magnetite may be ubiquitous in the lunar regolith of the high-Ti region. SCIENCE ADVANCES 2024; 10:eadn2301. [PMID: 39303040 DOI: 10.1126/sciadv.adn2301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 08/16/2024] [Indexed: 09/22/2024]
Abstract
Magnetite is rare on the Moon. The ubiquitous presence of magnetite in lunar soil has been hypothesized in previous Apollo Mössbauer spectroscopy and electron spin resonance studies, but there is currently no mineralogical evidence to prove it. Here, we report a large number of submicroscopic magnetite particles embedded within iron-sulfide on the surface of Chang'e-5 glass, with a close positive correlation between magnetite content and the TiO2 content of the surrounding glass. The morphology and mineralogy of the iron-sulfide grains suggest that these magnetite particles formed via an impact process between iron-sulfide droplets and silicate glass melt, and ilmenite is necessary for magnetite formation. Magnetite in lunar glass is a potential candidate for the "magnetite-like" phase detected in the Apollo era and suggests that impact-induced submicroscopic magnetite may be ubiquitous in high-Ti regions of the Moon. Moreover, these impact-induced magnetite particles may be crucial for understanding the lunar magnetic anomalies and mineral components of the deep Moon.
Collapse
Affiliation(s)
- Zhi Cao
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- Planetary Science Institute, State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, 430074 Wuhan, China
| | - Zhuang Guo
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- NWU-HKU Joint Center of Earth and Planetary Sciences, Department of Geology, Northwest University, Xi'an 710069, China
| | - Chen Li
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
| | - Sizhe Zhao
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, 999078 Macau, China
| | - Yang Li
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, 230026 Hefei, China
| | - Qi He
- Planetary Science Institute, State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, 430074 Wuhan, China
| | - Yuanyun Wen
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
| | - Zhiyong Xiao
- Planetary Environmental and Astrobiological Research Laboratory, School of Atmospheric Sciences, Sun Yat-Sen University, 519082 Zhuhai, China
| | - Xiongyao Li
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, 230026 Hefei, China
| | - Long Xiao
- Planetary Science Institute, State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, 430074 Wuhan, China
| | - Lifang Li
- Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, 150001 Harbin, China
| | - Junhu Wang
- Center for Advanced Mössbauer Spectroscopy, Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian, China
| | - Jianzhong Liu
- Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
- Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, 230026 Hefei, China
| |
Collapse
|
2
|
Brown JM, McQueen RG. Phase transitions, Grüneisen parameter, and elasticity for shocked iron between 77 GPa and 400 GPa. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb091ib07p07485] [Citation(s) in RCA: 593] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
3
|
|
4
|
Ahrens TJ, Jeanloz R. Pyrite: Shock compression, isentropic release, and composition of the Earth's core. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb092ib10p10363] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
5
|
Huang H, Fei Y, Cai L, Jing F, Hu X, Xie H, Zhang L, Gong Z. Evidence for an oxygen-depleted liquid outer core of the Earth. Nature 2011; 479:513-6. [PMID: 22113693 DOI: 10.1038/nature10621] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 10/03/2011] [Indexed: 11/09/2022]
Abstract
On the basis of geophysical observations, cosmochemical constraints, and high-pressure experimental data, the Earth's liquid outer core consists of mainly liquid iron alloyed with about ten per cent (by weight) of light elements. Although the concentrations of the light elements are small, they nevertheless affect the Earth's core: its rate of cooling, the growth of the inner core, the dynamics of core convection, and the evolution of the geodynamo. Several light elements-including sulphur, oxygen, silicon, carbon and hydrogen-have been suggested, but the precise identity of the light elements in the Earth's core is still unclear. Oxygen has been proposed as a major light element in the core on the basis of cosmochemical arguments and chemical reactions during accretion. Its presence in the core has direct implications for Earth accretion conditions of oxidation state, pressure and temperature. Here we report new shockwave data in the Fe-S-O system that are directly applicable to the outer core. The data include both density and sound velocity measurements, which we compare with the observed density and velocity profiles of the liquid outer core. The results show that we can rule out oxygen as a major light element in the liquid outer core because adding oxygen into liquid iron would not reproduce simultaneously the observed density and sound velocity profiles of the outer core. An oxygen-depleted core would imply a more reduced environment during early Earth accretion.
Collapse
Affiliation(s)
- Haijun Huang
- School of Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Sata N, Hirose K, Shen G, Nakajima Y, Ohishi Y, Hirao N. Compression of FeSi, Fe3C, Fe0.95O, and FeS under the core pressures and implication for light element in the Earth's core. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jb006975] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
7
|
Fei Y, Prewitt CT, Mao HK, Bertka CM. Structure and Density of FeS at High Pressure and High Temperature and the Internal Structure of Mars. Science 2010; 268:1892-4. [PMID: 17797532 DOI: 10.1126/science.268.5219.1892] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In situ x-ray diffraction measurements revealed that FeS, a possible core material for the terrestrial planets, transforms to a hexagonal NiAs superstructure with axial ratio (c/a) close to the ideal close-packing value of 1.63 at high pressure and high temperature. The high-pressure-temperature phase has shorter Fe-Fe distances than the low-pressure phase. Significant shortening of the Fe-Fe distance would lead to metallization of FeS, resulting in fundamental changes in physical properties of FeS at high pressure and temperature. Calculations using the density of the high-pressure-temperature FeS phase indicate that the martian core-mantle boundary occurs within the silicate perovskite stability field.
Collapse
|
8
|
Balog PS, Secco RA, Rubie DC, Frost DJ. Equation of state of liquid Fe-10 wt % S: Implications for the metallic cores of planetary bodies. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2001jb001646] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- P. S. Balog
- Department of Earth Sciences; University of Western Ontario; London Ontario Canada
| | - R. A. Secco
- Department of Earth Sciences; University of Western Ontario; London Ontario Canada
| | - D. C. Rubie
- Bayerisches Geoinstitut; Universität Bayreuth; Bayreuth Germany
| | - D. J. Frost
- Bayerisches Geoinstitut; Universität Bayreuth; Bayreuth Germany
| |
Collapse
|
9
|
Physical properties of iron in the inner core. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/gd031p0137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
10
|
McDonough WF. The Composition of the Earth. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0074-6142(01)80077-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
|
11
|
Stixrude L, Wasserman E, Cohen RE. Composition and temperature of Earth's inner core. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb02125] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
12
|
Fei Y, Bertka CM, Finger LW. High-Pressure Iron-Sulfur Compound, Fe3S2, and Melting Relations in the Fe-FeS System. Science 1997; 275:1621-3. [PMID: 9054351 DOI: 10.1126/science.275.5306.1621] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An iron-sulfur compound (Fe3S2) was synthesized at pressures greater than 14 gigapascals in the system Fe-FeS. The formation of Fe3S2 changed the melting relations from a simple binary eutectic system to a binary system with an intermediate compound that melted incongruently. The eutectic temperature in the system at 14 gigapascals was about 400°C lower than that extrapolated from Usselman's data, implying that previous thermal models of Fe-rich planetary cores could overestimate core temperature. If it is found in a meteorite, the Fe3S2 phase could also be used to infer the minimum size of a parent body.
Collapse
Affiliation(s)
- Y Fei
- Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, DC 20015, USA
| | | | | |
Collapse
|
13
|
The Bakerian Lecture, 1983 - The Earth’s core: its composition, formation and bearing upon the origin of the Earth. ACTA ACUST UNITED AC 1997. [DOI: 10.1098/rspa.1984.0088] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The density of the outer core is about 3 % smaller than pure iron, which implies that the core contains a substantial amount of one or more low atomic mass elements. Candidates which have been suggested on various grounds include S, H, C, O, Si, and Mg. Plausible models of accretion of the Earth encounter difficulties in trapping sufficient S, H and C to explain the density deficit. On the other hand, entry of Si and Mg is not favoured by thermodynamic arguments. Oxygen is the most abundant element in the Earth and would be a prime candidate if it could be shown to be extensively soluble in molten iron at core temperatures and pressures. New experimental data on the solubility of FeO in molten iron are reviewed. They demonstrate that at atmospheric pressure, FeO is extensively soluble in iron at 2500 °C and that complete miscibility probably occurs above 2800 °C. Moreover, liquid iron in equilibrium with magnesiowüstite (Mg
0.8
Fe
0.2
)O also dissolves large quantities of FeO above 2800 °C. The solubility of FeO in molten iron is considerably increased by high pressures, because of the small partial molar volume of FeO in the Fe─FeO melt. If the core formed by segregation of metal originally dispersed throughout the Earth, it seems inevitable that it would have dissolved large amounts of FeO. The density of the outer core can be matched if it contains about 35 mol % FeO, a quantity that is readily explained by the new experimental data. Solution of FeO in iron causes the melting point of the metal phase to be depressed below the solidus temperature of the silicate phase assemblages in the mantle. A model for the formation of the core is described, based upon Fe-FeO phase relations at high temperatures and pressures. The model implies the presence of a high content of FeO in the Bulk Earth. This can be explained if the Earth accreted from a mixture of two components: A, a highly reduced, metal-rich devolatilized assemblage and B, a highly oxidized, volatile-rich assemblage similar to C1 chondrites. The formation of these components in the solar nebula is discussed. The large amount of FeO now inferred to be present in the Earth was mainly produced during accretion by oxidation of metallic iron from component A by water from component B. This two-component mixing model also provides an attractive explanation of some aspects of the chemistry of the Earth’s mantle including the abundances of siderophile and volatile elements.
Collapse
|
14
|
Anderson WW, Ahrens TJ. Shock temperature and melting in iron sulfides at core pressures. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95jb01972] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Anderson WW, Ahrens TJ. Physics of interplanetary dust capture via impact into organic polymer foams. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93je03147] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
16
|
Abstract
Recent studies are leading to a better understanding of the formation of the earth's metal core. This new information includes: better knowledge of the physics of metal segregation, improved geochemical data on the abundance of siderophile and chalcophile elements in the silicate part of the earth, and experimental data on the partitioning behavior of siderophile and chalcophile elements. Extensive melting of the earth as a result of giant impacts, accretion, or the presence of a dense blanketing atmosphere is thought to have led to the formation of the core. Collision between a planet-sized body and the earth may have also produced the moon. Near the end of accretion, core formation evidently ceased as upper mantle conditions became oxidizing. The accumulation of the oceans is a consequence of the change to oxidizing conditions.
Collapse
|
17
|
Knittle E, Jeanloz R. The high-pressure phase diagram of Fe0.94O: A possible constituent of the Earth's core. ACTA ACUST UNITED AC 1991. [DOI: 10.1029/90jb00653] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
18
|
|
19
|
Boness DA, Brown JM. The electronic band structures of iron, sulfur, and oxygen at high pressures and the Earth's core. ACTA ACUST UNITED AC 1990. [DOI: 10.1029/jb095ib13p21721] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
20
|
Williams Q, Jeanloz R. Melting relations in the iron-sulfur system at ultra-high pressures: Implications for the thermal state of the Earth. ACTA ACUST UNITED AC 1990. [DOI: 10.1029/jb095ib12p19299] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
21
|
|
22
|
Olson P, Schubert G, Anderson C. Plume formation in the D″-layer and the roughness of the core–mantle boundary. Nature 1987. [DOI: 10.1038/327409a0] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
23
|
6. Shock Wave Techniques for Geophysics and Planetary Physics. METHODS IN EXPERIMENTAL PHYSICS 1987. [DOI: 10.1016/s0076-695x(08)60587-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
24
|
|
25
|
|