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Earth’s early continental crust formed from wet and oxidizing arc magmas
The use of two zircon oxybarometers to simultaneously determine fO2 and H2O contents shows that Archaean granitoids were mostly formed from relatively oxidizing and H2O-rich magmas, probably at ancient subduction zones.
- Rong-Feng Ge
- , Simon A. Wilde
- & Xiao-Lei Wang
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Carbonate-rich crust subduction drives the deep carbon and chlorine cycles
New experiments show that most carbonates in carbonate-rich crustal rocks survive devolatilization and hydrous melting in cold and warm subduction zones, demonstrating their role in driving the deep carbon and chlorine cycles since the Mesoproterozoic.
- Chunfei Chen
- , Michael W. Förster
- & Svyatoslav S. Shcheka
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Remote detection of a lunar granitic batholith at Compton–Belkovich
Measurements from the Chang’e-1 and Chang’e-2 microwave instruments reveal an anomalously hot geothermal source on the Moon that is best explained by a roughly 50-kilometre-diameter granitic system below the geological feature known as Compton–Belkovich.
- Matthew A. Siegler
- , Jianqing Feng
- & Mackenzie N. White
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Deep, ultra-hot-melting residues as cradles of mantle diamond
New thermodynamic and geochemical modelling of melting shows that the observed composition of the cratonic mantle can be reproduced by deep and very hot melting, obviating the need for shallow melting and lithospheric stacking.
- Carl Walsh
- , Balz S. Kamber
- & Emma L. Tomlinson
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Extreme redox variations in a superdeep diamond from a subducted slab
The authors investigate chemical anomalies in superdeep diamond inclusions, leading them to suggest that there is an extremely variable redox environment in the deep mantle.
- Fabrizio Nestola
- , Margo E. Regier
- & Jeffrey W. Harris
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Article
| Open AccessRapid shifting of a deep magmatic source at Fagradalsfjall volcano, Iceland
Primitive lavas of the Fagradalsfjall eruption present a window into the deep roots of a magmatic system previously inaccessible to near-real-time investigation, showing that eruptible batches of basaltic magma mix on a timescale of weeks.
- Sæmundur A. Halldórsson
- , Edward W. Marshall
- & Andri Stefánsson
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| Open AccessNon-KREEP origin for Chang’e-5 basalts in the Procellarum KREEP Terrane
Isotopic analysis of basalt clasts returned from the Moon by the Chang’e-5 mission indicates that the rocks were derived from a mantle source that lacked potassium, rare-earth elements and phosphorus.
- Heng-Ci Tian
- , Hao Wang
- & Fu-Yuan Wu
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| Open AccessA dry lunar mantle reservoir for young mare basalts of Chang’e-5
Water abundance and hydrogen isotope compositions of two-billion-year-old basalt samples returned from the Moon by the Chang’e-5 mission suggest that the samples came from a relatively dry mantle source.
- Sen Hu
- , Huicun He
- & Ziyuan Ouyang
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Thermochemical lithosphere differentiation and the origin of cratonic mantle
A model is proposed for the origin of cratonic lithospheric mantle in which rifting and melting in the hot, early Earth mantle leave behind large volumes of stiffer, depleted mantle.
- Fabio A. Capitanio
- , Oliver Nebel
- & Peter A. Cawood
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Intraplate volcanism originating from upwelling hydrous mantle transition zone
The widespread intraplate volcanism in northeast China and the unusual ‘petit-spot’ volcanoes offshore Japan could have resulted from the interaction of the subducting Pacific slab with a hydrous mantle transition zone.
- Jianfeng Yang
- & Manuele Faccenda
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Geochemical evidence for high volatile fluxes from the mantle at the end of the Archaean
Depletion of Archaean atmospheric xenon in 129Xe relative to the modern atmosphere might indicate that a short burst of mantle activity took place around 2.6 to 2.2 billion years ago.
- Bernard Marty
- , David V. Bekaert
- & Claude Jaupart
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Letter |
Kimberlites reveal 2.5-billion-year evolution of a deep, isolated mantle reservoir
Globally distributed kimberlites have their origins in a single, homogeneous early Earth reservoir that was subsequently perturbed, probably by subduction along the margins of Pangaea, around 200 million years ago.
- Jon Woodhead
- , Janet Hergt
- & Geoff Nowell
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Seismic velocities of CaSiO3 perovskite can explain LLSVPs in Earth’s lower mantle
Unexpectedly low seismic velocities of CaSiO3 perovskite in deeply subducted oceanic crust can explain the properties of anomalous continent-sized regions in Earth’s lower mantle.
- A. R. Thomson
- , W. A. Crichton
- & S. A. Hunt
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Letter |
Metamorphism and the evolution of plate tectonics
Variability in Earth’s thermal gradients, recorded by metamorphic rocks through time, shows that Earth’s modern plate tectonics developed gradually since the Neoarchaean era, three billion years ago.
- Robert M. Holder
- , Daniel R. Viete
- & Tim E. Johnson
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Letter |
Deep roots for mid-ocean-ridge volcanoes revealed by plagioclase-hosted melt inclusions
Volatile contents of plagioclase-hosted melt inclusions from volcanoes at the Gakkel mid-ocean ridge suggest that magmatic crystallization extends to depths of 16 kilometres, much deeper than suggested by olivine-hosted melt inclusions.
- Emma N. Bennett
- , Frances E. Jenner
- & C. Johan Lissenberg
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Letter |
Deep hydrous mantle reservoir provides evidence for crustal recycling before 3.3 billion years ago
Hydrogen isotopes and compositions of melt inclusions in olivine in komatiites indicate a hydrous source produced by recycling of seawater-altered crust into the deep mantle over 3.3 billion years ago.
- Alexander V. Sobolev
- , Evgeny V. Asafov
- & Gary R. Byerly
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Sampling the volatile-rich transition zone beneath Bermuda
The formation of Bermuda sampled a previously unknown mantle reservoir that is characterized by silica-undersaturated melts enriched in volatiles and by a unique lead isotopic signature, which suggests that the source is young.
- Sarah E. Mazza
- , Esteban Gazel
- & Alexander V. Sobolev
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Letter |
Chemical differentiation, cold storage and remobilization of magma in the Earth’s crust
Magma storage and differentiation in the Earth’s crust mainly occurs by reactive melt flow in long-lived mush reservoirs, rather than by fractional crystallization in magma chambers, as previously thought.
- M. D. Jackson
- , J. Blundy
- & R. S. J. Sparks
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Abiotic synthesis of amino acids in the recesses of the oceanic lithosphere
High-resolution imaging techniques show that aromatic amino acids such as tryptophan formed abiotically and were subsequently preserved at depth beneath the Atlantis Massif of the Mid-Atlantic Ridge, supporting the hydrothermal theory for the origin of life.
- Bénédicte Ménez
- , Céline Pisapia
- & Matthieu Réfrégiers
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Xenon isotopic constraints on the history of volatile recycling into the mantle
Mantle xenon isotope systematics reveals that no substantial recycling of atmospheric xenon into the deep Earth occurred before 2.5 billion years ago, indicating that downwellings were drier in the Archaean era than today.
- Rita Parai
- & Sujoy Mukhopadhyay
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Low-temperature crystallization of granites and the implications for crustal magmatism
Thermobarometry and diffusion modelling in quartz crystals show that some granites may crystallize at much lower temperatures than we had thought, possibly explaining observations of cold magma storage.
- Michael R. Ackerson
- , B. O. Mysen
- & E. B. Watson
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Rapid emergence of subaerial landmasses and onset of a modern hydrologic cycle 2.5 billion years ago
The use of triple-oxygen-isotope data from continental shales spanning the past 3.7 billion years suggests that continental crust with near-modern average elevation and extent emerged about 2.5 billion years ago.
- I. N. Bindeman
- , D. O. Zakharov
- & A. Bekker
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Earthquake-induced transformation of the lower crust
During continent collision and associated mountain building, a surprisingly large volume of the lower crust is shown to be affected by earthquake aftershocks, producing a top-down effect on crustal geodynamics.
- Bjørn Jamtveit
- , Yehuda Ben-Zion
- & Håkon Austrheim
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Hadean silicate differentiation preserved by anomalous 142Nd/144Nd ratios in the Réunion hotspot source
Neodymium-142 isotope data from young Réunion Island volcanic rocks reflect the effects of geological processes that occurred more than four billion years ago, showing that the deep mantle may preserve geochemical signatures of the primordial Earth.
- Bradley J. Peters
- , Richard W. Carlson
- & Mary F. Horan
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A record of deep-ocean dissolved O2 from the oxidation state of iron in submarine basalts
Deep-ocean O2 concentrations over the past 3.5 billion years are estimated using the oxidation state of iron in submarine basalts and indicate that deep-ocean oxygenation occurred in the Phanerozoic.
- Daniel A. Stolper
- & C. Brenhin Keller
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The divergent fates of primitive hydrospheric water on Earth and Mars
Modelling the reactions of water with the crusts of early Earth and Mars sheds light on how water was transported through their crusts to give the surfaces we see today.
- Jon Wade
- , Brendan Dyck
- & Andrew J. Smye
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A compositional tipping point governing the mobilization and eruption style of rhyolitic magma
Measurements of the composition-dependent viscosity of rhyolitic magma reveal a tipping point that changes the physical properties of the melt and controls the transition between effusive and explosive eruptions.
- D. Di Genova
- , S. Kolzenburg
- & D. B. Dingwell
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Continental crust formation on early Earth controlled by intrusive magmatism
Modelling of two modes of continental crust formation suggests that before plate tectonics began operating, the Archean early Earth’s tectonic regime was governed by intrusive magmatism.
- A. B. Rozel
- , G. J. Golabek
- & T. Gerya
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Earth’s first stable continents did not form by subduction
Phase equilibria modelling of rocks from Western Australia confirms that the ancient continental crust could have formed by multistage melting of basaltic ‘parents’ along high geothermal gradients—a process incompatible with modern-style subduction.
- Tim E. Johnson
- , Michael Brown
- & R. Hugh Smithies
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Mid-ocean-ridge seismicity reveals extreme types of ocean lithosphere
The structure and accretion modes of two end-member types of oceanic lithosphere are described using a detailed seismicity survey along 390 kilometres of an ultraslow ridge axis, indicating deeper seismicity in amagmatic regions and explaining the uneven crustal production at ultraslow-spreading ridges.
- Vera Schlindwein
- & Florian Schmid
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Komatiites reveal a hydrous Archaean deep-mantle reservoir
Archaean komatiites are shown to originate in hot mantle plumes that entrained hydrous material from deep in the mantle.
- Alexander V. Sobolev
- , Evgeny V. Asafov
- & Stepan P. Krasheninnikov
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Slab melting as a barrier to deep carbon subduction
Experiments show that carbonated oceanic crust subducting into the mantle will intersect the melting curve at depths of about 300 to 700 kilometres, creating a barrier to direct carbonate recycling into the deep mantle.
- Andrew R. Thomson
- , Michael J. Walter
- & Richard A. Brooker
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Article |
Volcanic–plutonic parity and the differentiation of the continental crust
A global geochemical data set of volcanic and plutonic rocks indicates that differentiation trends from primitive basaltic to felsic compositions for volcanic versus plutonic samples are generally indistinguishable in subduction-zone settings, but are divergent in continental rifts.
- C. Brenhin Keller
- , Blair Schoene
- & Jon M. Husson
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Experimental constraints on the electrical anisotropy of the lithosphere–asthenosphere system
Electrical anisotropy measurements at high temperatures and quasi-hydrostatic pressures on previously deformed olivine plus melt samples show that electrical conductivity is much higher in the direction of deformation; this is confirmed with a layered electrical model of the asthenosphere and lithosphere that reproduces existing field data.
- Anne Pommier
- , Kurt Leinenweber
- & James A. Tyburczy
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Spreading continents kick-started plate tectonics
The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth’s interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.
- Patrice F. Rey
- , Nicolas Coltice
- & Nicolas Flament
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Zircons reveal magma fluxes in the Earth’s crust
The age distributions of zircons (found in magmatic rocks) enable magma fluxes in the Earth’s crust to be calculated, providing insight into geological processes such as ore deposit formation and volcanic eruptions.
- Luca Caricchi
- , Guy Simpson
- & Urs Schaltegger
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Electrical conductivity during incipient melting in the oceanic low-velocity zone
Determination of the electrical conductivity of carbon-dioxide- and water-rich melts, which are typically produced at the onset of mantle melting, shows that incipient melts can trigger the high electrical conductivities found in oceanic regions of the asthenosphere.
- David Sifré
- , Emmanuel Gardés
- & Fabrice Gaillard
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Hydrous mantle transition zone indicated by ringwoodite included within diamond
X-ray diffraction, Raman and infrared spectroscopic evidence for the inclusion of water-rich ringwoodite in diamond from Juína, Brazil, indicates that, at least locally, the Earth’s transition zone is hydrous to about 1 weight per cent.
- D. G. Pearson
- , F. E. Brenker
- & L. Vincze
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Rapid remobilization of magmatic crystals kept in cold storage
We lack thermal histories for magma reservoirs, but here the magma under Mount Hood (Oregon, USA) is shown to have been too cold to mobilize for most of the time it has been stored, which implies that magma mobilizes (at which point it can be imaged geophysically) very quickly prior to eruption.
- Kari M. Cooper
- & Adam J. R. Kent
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Primitive layered gabbros from fast-spreading lower oceanic crust
Drilling by the Integrated Ocean Drilling Program has recovered primitive, modally layered, orthopyroxene-bearing cumulate rocks from the lower plutonic crust formed at a fast-spreading ridge, leading to a better-constrained estimate of the bulk composition of fast-spreading oceanic crust.
- Kathryn M. Gillis
- , Jonathan E. Snow
- & Robert P. Wintsch
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Origin and age of the earliest Martian crust from meteorite NWA 7533
Chemical analysis of the meteorite NWA 7533 indicates that it may be a Martian regolith breccia and, if so, that the crust of Mars may have formed in the first 100 million years of the planet’s history.
- M. Humayun
- , A. Nemchin
- & D. Deldicque
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Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars
Several irregularly shaped craters located within Arabia Terra, Mars, are interpreted as a new type of highland volcanic construct, similar to supervolcanoes on Earth, fundamentally changing the picture of ancient volcanism and climate evolution on Mars.
- Joseph R. Michalski
- & Jacob E. Bleacher
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Melting during late-stage rifting in Afar is hot and deep
Large volumes of molten rock break through the Earth’s crust during continental breakup, and here it is shown that the cause is primarily very high mantle temperatures (under a thick plate), rather than plate thinning.
- D. J. Ferguson
- , J. Maclennan
- & G. Yirgu
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Anomalous sulphur isotopes in plume lavas reveal deep mantle storage of Archaean crust
Mass-independent fractionation of sulphur isotopes in basalts from the oceanic island of Mangaia (Cook Islands) indicates ancient subducted Archaean (>2.45 Gyr) oceanic crust and lithosphere survives in the mantle to be sampled beneath hotspot volcanoes.
- Rita A. Cabral
- , Matthew G. Jackson
- & Erik H. Hauri
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Water and hydrogen are immiscible in Earth’s mantle
Experimental evidence is presented which shows that water and hydrogen can coexist as two separate, immiscible phases in Earth’s mantle; such immiscibility might be responsible for the formation of enigmatic, extremely reducing domains inferred to exist in the mantle, and may provide a mechanism for the rapid oxidation of Earth’s upper mantle immediately following core formation.
- Enikő Bali
- , Andreas Audétat
- & Hans Keppler
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Carbon-dioxide-rich silicate melt in the Earth’s upper mantle
Carbon-dioxide-rich kimberlitic melt explains the low velocity and high electrical conductivity of the mantle asthenosphere and controls the flux of incompatible elements at oceanic ridges.
- Rajdeep Dasgupta
- , Ananya Mallik
- & Marc M. Hirschmann
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Nickel and helium evidence for melt above the core–mantle boundary
Several nickel-rich and helium-rich lava samples from ocean islands and large igneous provinces suggest that mantle plume material formed by core–mantle interaction during the crystallization of a melt-rich layer or basal magma ocean.
- Claude Herzberg
- , Paul D. Asimow
- & Dennis Geist
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The oxidation state of the mantle and the extraction of carbon from Earth’s interior
The oxygen fugacity of the deepest rock samples from Earth’s mantle is found to be more oxidized than previously thought, with the result that carbon in the asthenospheric mantle will be hosted as graphite or diamond but will be oxidized to produce carbonate melt through the reduction of Fe3+ in silicate minerals during upwelling.
- Vincenzo Stagno
- , Dickson O. Ojwang
- & Daniel J. Frost
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The global pattern of trace-element distributions in ocean floor basalts
Global distributions of trace elements in ocean floor basalts are found to describe a systematic pattern that is due to cycling of magma through the global ensemble of magma chambers.
- Hugh St C. O’Neill
- & Frances E. Jenner