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Teurtrie A, Perraudin N, Holvoet T, Chen H, Alexander DTL, Obozinski G, Hébert C. espm: A Python library for the simulation of STEM-EDXS datasets. Ultramicroscopy 2023; 249:113719. [PMID: 37003127 DOI: 10.1016/j.ultramic.2023.113719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 04/01/2023]
Abstract
We present two open-source Python packages: "electron spectro-microscopy" (espm) and "electron microscopy tables" (emtables). The espm software enables the simulation of scanning transmission electron microscopy energy-dispersive X-ray spectroscopy datacubes, based on user-defined chemical compositions and spatial abundance maps of constituent phases. The simulation process uses X-ray emission cross-sections generated via state-of-the-art calculations made with emtables. These tables are designed to be easily modifiable, either manually or using espm. The simulation framework is designed to test the application of decomposition algorithms for the analysis of STEM-EDX spectrum images with access to a known ground truth. We validate our approach using the case of a complex geology-related sample, comparing raw simulated and experimental datasets and the outputs of their non-negative matrix factorization. In addition to testing machine learning algorithms, our packages will also help experimental design, for instance, predicting dataset characteristics or establishing minimum counts needed to measure nanoscale features.
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Affiliation(s)
- Adrien Teurtrie
- Electron Spectrometry and Microscopy Laboratory, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland; Unité Matériaux et Transformations, UMR-CNRS 8207, Université de Lille, Cité scientifique, Bâtiment C6, 59655, Villeneuve d'Ascq, France
| | - Nathanaël Perraudin
- Swiss Data Science Center, EPFL & ETH Zürich, Turnerstrasse 1, 8092, Zürich, Switzerland
| | - Thomas Holvoet
- Swiss Data Science Center, EPFL & ETH Zürich, Turnerstrasse 1, 8092, Zürich, Switzerland
| | - Hui Chen
- Electron Spectrometry and Microscopy Laboratory, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Duncan T L Alexander
- Electron Spectrometry and Microscopy Laboratory, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Guillaume Obozinski
- Swiss Data Science Center, EPFL & ETH Zürich, Turnerstrasse 1, 8092, Zürich, Switzerland
| | - Cécile Hébert
- Electron Spectrometry and Microscopy Laboratory, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland; Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
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2
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Guo M, Korenaga J. The combined Hf and Nd isotope evolution of the depleted mantle requires Hadean continental formation. SCIENCE ADVANCES 2023; 9:eade2711. [PMID: 36961892 PMCID: PMC10038339 DOI: 10.1126/sciadv.ade2711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
The onset and rates of continental growth are first-order indicators of early Earth dynamics, and whether substantial crust existed in the Hadean or much later has long been debated. Here, we present a theoretical analysis of published Hf and Nd isotopic data representing the depleted mantle and demonstrate that continental growth must have started in the early Hadean. Whereas the traditional interpretation of depleted mantle signatures in crustal rocks assumes unrealistic instantaneous mantle mixing, our modeling incorporates the effect of a finite mixing time over which these signatures are recorded in rocks produced through mantle melting. This effect is shown to delay, by as much as 0.65 to 0.75 billion years, the appearance of the earliest depleted mantle signatures in continental crust. Our results suggest that published observations of εHf, ε143Nd, and μ142Nd require Hadean growth of continental crust, with a minimum of 50% of today's continental volume already existing by the end of Hadean.
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3
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Nabiei F, Badro J, Boukaré C, Hébert C, Cantoni M, Borensztajn S, Wehr N, Gillet P. Investigating Magma Ocean Solidification on Earth Through Laser-Heated Diamond Anvil Cell Experiments. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL092446. [PMID: 34219835 PMCID: PMC8244043 DOI: 10.1029/2021gl092446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/18/2021] [Accepted: 05/22/2021] [Indexed: 05/09/2023]
Abstract
We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid line of descent were determined and used to assemble the melting phase diagram. In a pyrolitic magma ocean, the first mineral to crystallize in the deep mantle is iron-depleted calcium-bearing bridgmanite. From the phase diagram, we estimate that the initial 33%-36% of the magma ocean will crystallize to form such a buoyant bridgmanite. Substantial calcium solubility in bridgmanite is observed up to 129 GPa, and significantly delays the crystallization of the calcium silicate perovskite phase during magma ocean solidification. Residual melts are strongly iron-enriched as crystallization proceeds, making them denser than any of the coexisting solids at deep mantle conditions, thus supporting the terrestrial basal magma ocean hypothesis (Labrosse et al., 2007).
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Affiliation(s)
- Farhang Nabiei
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Electron Spectrometry and Microscopy LaboratoryEPFLLausanneSwitzerland
| | - James Badro
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Charles‐Édouard Boukaré
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Cécile Hébert
- Electron Spectrometry and Microscopy LaboratoryEPFLLausanneSwitzerland
| | - Marco Cantoni
- Interdisciplinary Centre for Electron MicroscopyEPFLLausanneSwitzerland
| | | | - Nicolas Wehr
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Philippe Gillet
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
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Williams HM, Matthews S, Rizo H, Shorttle O. Iron isotopes trace primordial magma ocean cumulates melting in Earth's upper mantle. SCIENCE ADVANCES 2021; 7:7/11/eabc7394. [PMID: 33712459 PMCID: PMC7954453 DOI: 10.1126/sciadv.abc7394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
The differentiation of Earth ~4.5 billion years (Ga) ago is believed to have culminated in magma ocean crystallization, crystal-liquid separation, and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate because of the scarcity of geochemical tracers of lower mantle mineralogy. The Fe isotope compositions (δ57Fe) of ancient mafic rocks can be used to reconstruct the mineralogy of their mantle source regions. We present Fe isotope data for 3.7-Ga metabasalts from the Isua Supracrustal Belt (Greenland). The δ57Fe signatures of these samples extend to values elevated relative to modern equivalents and define strong correlations with fluid-immobile trace elements and tungsten isotope anomalies (μ182W). Phase equilibria models demonstrate that these features can be explained by melting of a magma ocean cumulate component in the upper mantle. Similar processes may operate today, as evidenced by the δ57Fe and μ182W heterogeneity of modern oceanic basalts.
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Affiliation(s)
- Helen M Williams
- Department of Earth Sciences, The University of Cambridge, Cambridge, UK.
| | - Simon Matthews
- Department of Earth Sciences, The University of Cambridge, Cambridge, UK
| | - Hanika Rizo
- Department of Earth Sciences, Carleton University, Ottawa, ON, Canada
| | - Oliver Shorttle
- Department of Earth Sciences, The University of Cambridge, Cambridge, UK
- Institute of Astronomy, The University of Cambridge, Cambridge, UK
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5
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Hadean silicate differentiation preserved by anomalous 142Nd/ 144Nd ratios in the Réunion hotspot source. Nature 2018; 555:89-93. [PMID: 29493592 DOI: 10.1038/nature25754] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/02/2018] [Indexed: 11/08/2022]
Abstract
Active volcanic hotspots can tap into domains in Earth's deep interior that were formed more than two billion years ago. High-precision data on variability in tungsten isotopes have shown that some of these domains resulted from differentiation events that occurred within the first fifty million years of Earth history. However, it has not proved easy to resolve analogous variability in neodymium isotope compositions that would track regions of Earth's interior whose composition was established by events occurring within roughly the first five hundred million years of Earth history. Here we report 142Nd/144Nd ratios for Réunion Island igneous rocks, some of which are resolvably either higher or lower than the ratios in modern upper-mantle domains. We also find that Réunion 142Nd/144Nd ratios correlate with helium-isotope ratios (3He/4He), suggesting parallel behaviour of these isotopic systems during very early silicate differentiation, perhaps as early as 4.39 billion years ago. The range of 142Nd/144Nd ratios in Réunion basalts is inconsistent with a single-stage differentiation process, and instead requires mixing of a conjugate melt and residue formed in at least one melting event during the Hadean eon, 4.56 billion to 4 billion years ago. Efficient post-Hadean mixing nearly erased the ancient, anomalous 142Nd/144Nd signatures, and produced the relatively homogeneous 143Nd/144Nd composition that is characteristic of Réunion basalts. Our results show that Réunion magmas tap into a particularly ancient, primitive source compared with other volcanic hotspots, offering insight into the formation and preservation of ancient heterogeneities in Earth's interior.
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Nutman AP, Bennett VC, Friend CRL. The emergence of the Eoarchaean proto-arc: evolution of a c. 3700 Ma convergent plate boundary at Isua, southern West Greenland. ACTA ACUST UNITED AC 2013. [DOI: 10.1144/sp389.5] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractEoarchaean juvenile crust formed as ‘proto-arcs’. The northern side of the Isua supracrustal belt is an archetypal proto-arc, with ≥3720 Ma boninites, c. 3720 Ma basalts and gabbros, 3720–3710 Ma andesites, diorites and mafic tonalites, 3710–3700 Ma intermediate-felsic volcanic and sedimentary rocks and 3700–3690 Ma chemical sedimentary rocks. On its northern side there is an extensive body of 3700–3690 Ma tonalite. During its evolution, the c. 3700 Ma Isua volcanic–sedimentary assemblage was partitioned into tectonic slices, with intercalation of mantle dunites with pillow basalts, prior to intrusion of c. 3710 Ma quartz diorites. Partitioning also occurred at 3690–3660 Ma, when the 30–20 million years life of the c. 3700 Ma Isua proto-arc was terminated by juxtaposition with the c. 3800 Ma terrane that occurs along the south of the Isua supracrustal belt. The trace element chemistry for all the ≥3720–3700 Ma mafic to intermediate volcanic rocks indicates fluid-fluxing mantle melting. The c. 3690 Ma tonalites have signatures showing melting of garnet-bearing mafic (eclogite) sources. The Isua c. 3700 Ma assemblage developed at an intra-oceanic convergent plate boundary, and it has a life-cycle broadly analogous to (but not identical to) an oceanic island arc eventually accreted against older crust.
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Affiliation(s)
- Allen P. Nutman
- GeoQuEST Research Centre, School of Earth & Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vickie C. Bennett
- Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia
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The tungsten isotopic composition of the Earth's mantle before the terminal bombardment. Nature 2011; 477:195-8. [PMID: 21901010 DOI: 10.1038/nature10399] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 07/28/2011] [Indexed: 11/09/2022]
Abstract
Many precious, 'iron-loving' metals, such as gold, are surprisingly abundant in the accessible parts of the Earth, given the efficiency with which core formation should have removed them to the planet's deep interior. One explanation of their over-abundance is a 'late veneer'--a flux of meteorites added to the Earth after core formation as a 'terminal' bombardment that culminated in the cratering of the Moon. Some 3.8 billion-year-old rocks from Isua, Greenland, are derived from sources that retain an isotopic memory of events pre-dating this cataclysmic meteorite shower. These Isua samples thus provide a window on the composition of the Earth before such a late veneer and allow a direct test of its importance in modifying the composition of the planet. Using high-precision (less than 6 parts per million, 2 standard deviations) tungsten isotope analyses of these rocks, here we show that they have a isotopic tungsten ratio (182)W/(184)W that is significantly higher (about 13 parts per million) than modern terrestrial samples. This finding is in good agreement with the expected influence of a late veneer. We also show that alternative interpretations, such as partial remixing of a deep-mantle reservoir formed in the Hadean eon (more than four billion years ago) or core-mantle interaction, do not explain the W isotope data well. The decrease in mantle (182)W/(184)W occurs during the Archean eon (about four to three billion years ago), potentially on the same timescale as a notable decrease in (142)Nd/(144)Nd (refs 3 and 6). We speculate that both observations can be explained if late meteorite bombardment triggered the onset of the current style of mantle convection.
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McGuinness ET. Some Molecular Moments of the Hadean and Archaean Aeons: A Retrospective Overview from the Interfacing Years of the Second to Third Millennia. Chem Rev 2010; 110:5191-215. [DOI: 10.1021/cr050061l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Eugene T. McGuinness
- Department of Chemistry & Biochemistry, Seton Hall University, South Orange, New Jersey 07079-2690
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Caro G, Bourdon B, Halliday AN, Quitté G. Super-chondritic Sm/Nd ratios in Mars, the Earth and the Moon. Nature 2008; 452:336-9. [DOI: 10.1038/nature06760] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 01/18/2008] [Indexed: 11/09/2022]
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Rankenburg K, Brandon AD, Neal CR. Neodymium isotope evidence for a chondritic composition of the Moon. Science 2006; 312:1369-72. [PMID: 16741118 DOI: 10.1126/science.1126114] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Samarium-neodymium isotope data for six lunar basalts show that the bulk Moon has a 142Nd/144Nd ratio that is indistinguishable from that of chondritic meteorites but is 20 parts per million less than most samples from Earth. The Sm/Nd formation interval of the lunar mantle from these data is 215(-21)(+23) million years after the onset of solar system condensation. Because both Earth and the Moon likely formed in the same region of the solar nebula, Earth should also have a chondritic bulk composition. In order to mass balance the Nd budget, these constraints require that a complementary reservoir with a lower 142Nd/144Nd value resides in Earth's mantle.
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Affiliation(s)
- K Rankenburg
- NASA Johnson Space Center, Mail Code KR, Houston, TX 77058, USA.
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