Article
Geochemistry & Geophysics
Delphine Klaessens, Laurie Reisberg, David Jousselin
Summary: This study investigates the formation and evolution mechanism of dunites in the peridotites from the Batin region of the Oman ophiolite. Structural and geochemical analysis reveals that dunites in the Batin region are structurally and chemically distinct from those in other regions, possibly due to the influence of large pulses of radiogenic melts during their formation. The study suggests that understanding the flow dynamics of melts through peridotites is crucial in explaining the formation of dunites in ophiolites.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Changhong Wang, Zhaochong Zhang, Andrea Giuliani, Ronghua Cai, Zhiguo Cheng, Jingao Liu
Summary: This study investigates the composition and petrogenesis of plume-related magmas and ultramafic lamprophyres in the Tarim large igneous province, China. The results show that the aillikites in this region have high PPGE content and radiogenic Os isotopes, and limited variations in Sr-Nd isotope compositions. These findings indicate the presence of carbon-free subducted oceanic crust in the Tarim plume.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Mehmet Arslan, Irfan Temizel, Lukas Ackerman, Cem Yucel, Emel Abdioglu Yazar
Summary: The Cenozoic volcanic rocks from the Eastern Pontides Orogenic Belt in NE Turkey exhibit a wide range of variation in highly siderophile element (HSE) contents and Os isotope compositions, which are related to their mantle sources and magma evolution. Crustal assimilation played an important role in the evolution of the Eocene and Miocene volcanic rocks.
Article
Geochemistry & Geophysics
Honami Sato, Akira Ishikawa, Tetsuji Onoue, Yuki Tomimatsu, Manuel Rigo
Summary: Through analyzing stratigraphic variations, this study suggests that the Rochechouart impact event may have occurred before the Norian and Rhaetian boundary, leading to changes in the environment and biota.
Article
Geochemistry & Geophysics
Nicole Phelan, James M. D. Day, Jasmeet K. Dhaliwal, Yang Liu, Christopher A. Corder, Caleb Strom, Emily Pringle, Nelly Assayag, Pierre Cartigny, Kurt Marti, Frederic Moynier
Summary: This study reports isotopic and elemental abundance data for carbonaceous, ordinary, and enstatite chondrite meteorites and explores their variations in relation to other isotopic and elemental data. The study finds that carbonaceous chondrites are susceptible to disturbance in Re/Os ratios and that mineralogical variations and sample size have significant effects on element abundance. The study also expands the existing dataset of Re-Os isotope and HSE abundance measurements.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Robert W. Nicklas, James M. D. Day, Zoltan Vaci, Minghua Ren, Kathryn G. Gardner-Vandy, Kimberly T. Tait
Summary: Metal-silicate segregation is a fundamental mechanism in planetary differentiation. Brachinites and brachinite-like achondrites are olivine-dominated primitive achondrites that experienced partial melt removal and represent residues after inefficient metal-loss. New data on eight samples confirm their classifications and show correlations between total HSE abundance, Pt enrichment, and average olivine Fo.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Alan D. Brandon, Tod E. Waight, Igor S. Puchtel, James M. D. Day
Summary: Ocean island basalts exhibit significant variations in isotopic compositions, indicating contributions from multiple mantle sources including ancient refractory sources and recycled oceanic crustal components. Different isotopic systems show correlations, such as between Os and Pb, implying binary mixing between depleted and enriched sources. The presence of highly depleted mantle sources and recycled oceanic crust components are identified, with implications for the origin and evolution of the Icelandic plume.
Article
Geochemistry & Geophysics
Maria Rosaria Renna, Sonia Armandola, Harry Becker, Alessio Sanfilippo, Riccardo Tribuzio, Zaicong Wang
Summary: This study investigates the fractionation process of HSE and chalcogen elements in olivine-rich troctolites from Alpine Apennine Jurassic ophiolites. It reveals that the signature of these elements is acquired in response to sulfide segregation and reactive melt flow, which are key processes in shaping the HSE and chalcogen element signature of basalts erupted at (ultra-)slow spreading ridges.
Article
Geochemistry & Geophysics
Philipp Gleissner, Julie Salme, Harry Becker
Summary: The elevated water contents in lunar materials have prompted discussions on the volatile content of the lunar interior and the control of volatile element inventory in lunar magmatic rocks. New data on the mass fractions of volatile elements in lunar rocks reveal distribution processes during rock formation and provide insights into mantle source compositions. The results suggest that certain elements are less prone to degassing during magma ascent and effusion than previously proposed.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Multidisciplinary Sciences
Emily A. Worsham, Thorsten Kleine
Summary: Late accretion refers to the final addition of Earth's mass after the formation of the Moon, including a period of Late Heavy Bombardment (LHB) triggered by a late giant planet orbital instability. Research shows that impactors during the LHB and late accretion were of the same type and originated in the terrestrial planet region, suggesting that the LHB represents the end of accretion. Additionally, late-accreted bodies, originating from the inner solar system, cannot be the primary source of Earth's water.
Article
Geochemistry & Geophysics
Jie-Jun Jing, Yanhao Lin, Jurrien S. Knibbe, Wim van Westrenen
Summary: High-pressure, high-temperature experiments and numerical modeling have revealed the presence of stable garnet in the deep lunar mantle, which has important implications for lunar magma ocean crystallization and crust formation. The presence of garnet reduces the aluminum oxide content in the residual lunar magma ocean and affects the fractionation of rare earth elements. Additionally, the presence of garnet delays the saturation of plagioclase, resulting in a thinner lunar crust.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
C. M. Corrigan, K. Nagashima, C. Hilton, T. J. McCoy, R. D. Ash, H. A. Tornabene, R. J. Walker, W. F. McDonough, D. Rumble
Summary: The study reveals similarities between three ungrouped iron meteorites and group IVB iron meteorites, such as Ni enrichment and enrichments of certain refractory siderophile elements. However, there are also distinct genetic characteristics indicating different parent bodies for these meteorites.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Astronomy & Astrophysics
Kun Yang, Juergen Schmidt, Weiming Feng, Xiaodong Liu
Summary: In this study, the dynamics and distribution of dust particles escaping from the Moon were investigated using a model and numerical integrations. The results show that the average life spans of the particles rapidly increase with size, and an asymmetric torus is formed in the Earth-Moon system. Importantly, a considerable number of retrograde particles exist.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Geochemistry & Geophysics
Marine Paquet, James M. D. Day, Diana B. Brown, Christopher L. Waters
Summary: Late accretion on Earth led to potential heterogeneity in highly siderophile elements distribution within the mantle. Recent research showed that despite differences in spreading rate, abyssal peridotites from various mid-ocean ridges exhibit similar behavior in terms of HSE distribution and Os isotopes, indicating efficient mixing in Earth's mantle for these elements.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Multidisciplinary Sciences
Daniel P. Moriarty, Nick Dygert, Sarah N. Valencia, Ryan N. Watkins, Noah E. Petro
Summary: The lunar surface holds ancient and well-preserved records of Solar System history and planetary evolution processes. There is debate among scientists about the lithologies of the upper lunar mantle and where they may be exposed on the surface. By reviewing dynamical models and recent data, researchers are assessing candidate lithologies and their implications for lunar evolution.
NATURE COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
Connor D. Hilton, Richard D. Ash, Richard J. Walker
Summary: The projected relative abundances of highly siderophile elements (HSE) in different magmatic iron meteorite groups show no significant differences between noncarbonaceous and carbonaceous parent bodies. However, the absolute abundances of HSE, reflecting the core size, are more variable and higher in carbonaceous bodies compared to noncarbonaceous bodies. The chemical compositions and size of the cores are linked to the distribution of iron within the parent body, which is controlled by its oxidation state.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
I. S. Puchtel, R. W. Nicklas, J. Slagle, M. Horan, R. J. Walker, E. G. Nisbet, M. Locmelis
Summary: This study investigates the heterogeneity of Earth's early mantle by analyzing rock samples from the Pilbara Craton. The results show that the rocks in this region exhibit different characteristics compared to other Archean rocks and may not be associated with early magmatic activity. The study also reveals multiple episodes of partial mantle melting and melt extraction in the early mantle, which explains the significant variations in lithophile trace element ratios. Additionally, the analysis of trace element abundances and isotopic compositions provides important insights into mantle evolution and the Earth-Moon system.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
James M. D. Day
Summary: The noble gas isotope systematics of ocean island basalts suggest relatively undegassed and primitive mantle sources. The Canary Islands lavas confirm the dominance of gas-rich mantle sources in ocean island basalts.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Robert W. Nicklas, James M. D. Day, Kathryn G. Gardner-Vandy, Arya Udry
Summary: Using geochemical analyses, researchers have discovered a unique andesitic meteorite that has a different origin from other known andesitic meteorites, as well as Earth's continental crust. The study also suggests that this meteorite likely formed during the early history of the Solar System, with extensive andesitic magma differentiation occurring during this time, and the formation of andesitic crust not necessarily requiring plate tectonics.
Article
Geochemistry & Geophysics
Nao Nakanishi, Igor S. Puchtel, Richard J. Walker, Peter I. Nabelek
Summary: This study examines the positive W-182 anomalies in the upper mantle using Neoarchean and Paleoproterozoic rocks from the Black Hills in South Dakota, USA. The research finds that the anomalies decreased and nearly disappeared by the end of the Archean, likely due to mantle mixing processes. The specific mechanism behind this process needs further exploration through geodynamical modeling.
Article
Geochemistry & Geophysics
Hope A. Tornabene, Richard D. Ash, Richard J. Walker, Katherine R. Bermingham
Summary: The IC iron meteorite group is characterized by its mass-independent isotopic compositions and 182W age constraints, as well as siderophile element concentrations and modeling of crystal-liquid fractionation processes. The six IC irons analyzed have similar genetic isotopic compositions and are believed to have originated from the same parent body in the non-carbonaceous nebular reservoir. The abundances of siderophile elements in the IC irons are generally similar and show minor depletions in the more volatile siderophile elements. The initial parent body core was S-rich, and additional processes such as late-stage modification and metal-melt mixing are required to explain the range of highly siderophile element abundances within the first 100 million years of the Solar System's history.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Jasmeet K. K. Dhaliwal, James M. D. Day, Kimberly T. T. Tait
Summary: This study presents new petrography, mineral chemistry, and whole rock major, minor, and trace element abundance data for 29 dominantly unbrecciated basaltic eucrites and one cumulate eucrite. Pristinity filter analysis reveals that Cumulus Hills 04049, Elephant Moraine 90020, Grosvenor Range 95533, Pecora Escarpment 91245, and possibly Queen Alexander Range 97053 and Northwest Africa 1923 are pristine eucrites unaffected by metamorphism or impact contamination. The petrogenesis of eucrites can be explained by partial melting of a silicate mantle with prior metal-silicate equilibrium.
METEORITICS & PLANETARY SCIENCE
(2023)
Article
Mathematics
James Day
Summary: Vertically vibrating a liquid bath can enable a self-propelled wave-particle entity to move on its free surface. The horizontal dynamics of this walking droplet, subjected to an external drag force, can be adequately described by an integro-differential trajectory equation. In the case of a sinusoidal wave field, this equation is equivalent to a closed three-dimensional system of nonlinear ordinary differential equations. We establish a stability boundary and a quantized criterion for the partial integrability of the system in the meromorphic category.
BULLETIN OF THE AUSTRALIAN MATHEMATICAL SOCIETY
(2023)
Article
Geochemistry & Geophysics
Robert W. Nicklas, James M. D. Day, Zoltan Vaci, Minghua Ren, Kathryn G. Gardner-Vandy, Kimberly T. Tait
Summary: Metal-silicate segregation is a fundamental mechanism in planetary differentiation. Brachinites and brachinite-like achondrites are olivine-dominated primitive achondrites that experienced partial melt removal and represent residues after inefficient metal-loss. New data on eight samples confirm their classifications and show correlations between total HSE abundance, Pt enrichment, and average olivine Fo.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Daniel Peters, Hanika Rizo, Richard W. Carlson, Richard J. Walker, Roberta L. Rudnick, Ambre Luguet
Summary: Isotope dilution W whole-rock data is used to study the behavior of W in the continental lithospheric mantle. Tungsten concentrations are found to be high in peridotite samples, even in the most depleted ones. Fractionation of W from Th and U is observed with increasing melt depletion. The findings suggest that W metasomatism and re-equilibration may not be the cause of high W abundances in peridotites.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Emily M. Chiappe, Richard D. Ash, Richard J. Walker
Summary: Chemical and isotopic analysis of ten iron meteorites from the IIIE group reveals their similarities in terms of bulk siderophile element characteristics, suggesting a common origin through crystal-liquid fractionation. Modeling results indicate the parent melt composition of IIIE group with significantly higher highly siderophile element enrichment compared to non-carbonaceous (NC) chondrite-like parent body, indicating a core comprising a large portion of the parent body. Formation of the anomalous IIIE iron Aletai can be explained through the nonequilibrium mixing of an evolved liquid and early formed solid. The study also provides insights into the nucleosynthetic and metal-silicate segregation ages of IIIE irons and Aletai, suggesting their similarity to other NC-type iron meteorite parent bodies.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Marc C. Halfar, Bradley J. Peters, James M. D. Day, Maria Schonbachler
Summary: The Mascarene Islands in the western Indian Ocean are surface expressions of the Reunion hotspot. The lavas from these islands have uniform isotopic composition and may have contributions from different sources. The lavas from Rodrigues Island may contain a unique component that is not found in other islands.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Emily M. Chiappe, Richard D. Ash, Arto Luttinen, Sari Lukkari, Jukka Kuva, Connor D. Hilton, Richard J. Walker
Summary: The Lieksa meteorite, found in Finland in 2017, is classified as a pallasite due to its silicate content and the texture of metal enclosing the silicates. Its chemical characteristics and composition are distinct from known pallasites and iron meteorite groups, making it an ungrouped meteorite. The age of meteorite formation is estimated to be around 1.5 +/- 0.8 million years after the formation of calcium-aluminum-rich inclusions.
METEORITICS & PLANETARY SCIENCE
(2023)
Article
Geochemistry & Geophysics
Tarryn Aucamp, Geoffrey H. Howarth, Chad J. Peel, Gelu Costin, James M. D. Day, Petrus le Roux, James M. Scott, Ansgar Greshake, Rainer Bartoschewitz
Summary: The studied olivine-phyric shergottites exhibit similar mineralogical and geochemical characteristics, confirming a common source for these meteorites. A multi-stage formation model is proposed, involving partial melting of a depleted mantle source, initial crystallization at the crust-mantle boundary, magma evolution, and eruption at the surface. This model is similar to the formation of picritic flood basalt magmas on Earth.
METEORITICS & PLANETARY SCIENCE
(2023)
Article
Geochemistry & Geophysics
James M. D. Day, D. Graham Pearson, Bruce A. Kjarsgaard, Abigail K. Barker, Geoff M. Nowell, Nancy Joyce, David Lowry, Chiranjeeb Sarkar, Christopher Harrison
Summary: Melilitite, nephelinite, basanite, and alkali basalt, along with phonolite differentiates, form the Freemans Cove Complex (FCC) in the south-eastern extremity of Bathurst Island (Nunavut, Canada). New Ar-40/Ar-39 chronology indicates their emplacement between similar to 56 and similar to 54 million years ago within a localized extensional structure. The melilitites, nephelinites, and alkali basalts show no strong evidence for significant assimilation of crust, in contrast to some phonolites. Partial melting occurred within both the garnet- and spinel-facies mantle and sampled sources with He, O, Nd, Hf, and Os isotope characteristics indicative of peridotite with two distinct components. Magmatism in the FCC shows that rifting extended from the Labrador Sea to Bathurst Island and reached a zenith at similar to 55 Ma, during the Eurekan orogeny. The incompatible trace-element abundances and isotopic signatures of FCC rocks indicate melt generation occurred at the base of relatively thin lithosphere at the margin of a thick craton, with no mantle plume influence. FCC melt compositions are distinct from other continental rift magmatic provinces worldwide, and their metasomatized mantle source was plausibly formed synchronously with emplacement of Cretaceous kimberlites. The FCC illustrates that the range of isotopic compositions preserved in continental rift magmas are likely to be dominated by temporal changes in the extent of partial melting, as well as by the timing and degree of metasomatism recorded in the underlying continental lithosphere.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2023)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
