Article
Multidisciplinary Sciences
Shengyu Tian, Xin Ding, Yuhan Qi, Fei Wu, Yue Cai, Richard M. Gaschnig, Zicong Xiao, Weixin Lv, Roberta L. Rudnick, Fang Huang
Summary: The transition from mafic to felsic upper continental crust (UCC) is significant for the evolution of Earth and its inhabitants. V isotope ratios (δV-51) can provide insights into this transition. The δV-51 values of glacial diamictites from Archean to Paleozoic show that the UCC was dominantly mafic around 3 Ga but became felsic after that time.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Nicholas F. Wogan, David C. Catling, Kevin J. Zahnle, Mark W. Claire
Summary: The Great Oxidation Event (GOE), which marks the appearance of an oxygen-rich atmosphere, is considered one of the most important events since the origin of life. In this study, researchers developed a one-dimensional time-dependent photochemical model to investigate the behavior of the transitional atmosphere during changes in biogenic forcing. The simulations showed that transitions between anoxic and oxic atmospheres could occur within a few hundred to a few thousand years, and the stability of oxygen in the atmosphere was dependent on its concentration.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geochemistry & Geophysics
Daniel Garduno Ruiz, Colin Goldblatt, Anne-Sofie Ahm
Summary: A one-dimensional atmospheric photochemical model is used to study the effect of temperature and humidity variations on the evolution of O2 and O3 during the Great Oxidation Event (GOE). It is found that changes in temperature and humidity can significantly impact the levels of O2 and O3, with higher temperatures and humidity leading to higher levels of these gases.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Astronomy & Astrophysics
David S. Stevenson
Summary: This hypothesis article proposes a close correlation between the evolution of oxygenic photosynthesis and cyanobacterial diversification and the geological evolution of Earth in the Mesoarchaean to Neoarchaean. It suggests that the diversification of oxygenic photosynthetic species is tied to the growth of terrestrial continental crust, providing niches for their diversification. Additionally, the hypothesis suggests that some aerobic bacterial lineages evolved into anoxygenic photosynthetic species due to changes in selection following the reintroduction of ferruginous conditions in the oceans at 1.88 billion years ago. These conclusions are supported by phylogenetic evidence, emphasizing the dependence of the development and expansion of photosynthesis species on the geological evolution of Earth.
Article
Geochemistry & Geophysics
Guangliang Wu, Jian-Ming Zhu, Xiangli Wang, Thomas M. Johnson, Yongsheng He, Fang Huang, Lian-Xun Wang, Shao-Cong Lai
Summary: This study establishes the Ni isotopic composition of the upper continental crust (UCC) and reveals significant variations in different rock types and sediments. The variations are attributed to magmatic differentiation and source heterogeneity. The results also suggest limited variation in the Ni isotopes of the UCC since 3.5 Ga.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Shengyu Tian, Frederic Moynier, Edward C. Inglis, Roberta L. Rudnick, Fang Huang, Catherine Chauvel, John B. Creech, Richard M. Gaschnig, Zaicong Wang, Jing-Liang Guo
Summary: By analyzing the stable isotopic compositions of zirconium (Zr) in the continental crust, it was found that the Zr isotopic composition remained relatively stable throughout the evolution, revealing the compositional evolutionary history of the crust.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Genming Luo, Xiangkun Zhu, Shuijiong Wang, Shihong Zhang, Chaoqun Jiao
Summary: This paper briefly introduces the conception and research history of the Great Oxidation Event (GOE) in the early Paleoproterozoic and summarizes the primary geological and geochemical records of this event. It provides an overview of the significant progress in three fields of the GOE: the timing and process of its startup, its mechanisms, and its climatic-ecological effects. The paper also proposes four aspects for future explorations.
SCIENCE CHINA-EARTH SCIENCES
(2022)
Article
Geochemistry & Geophysics
Pousali Mukherjee, Kajaljyoti Borah, Alok Yadav
Summary: This study models receiver functions to investigate the crustal structures of the Precambrian Gondwanaland, finding variations in crustal thickness and composition among different cratons of different ages. The separation of Gondwana led to crustal delamination and destruction of thick crustal roots. Episodic cycles of crustal growth are also observed.
Article
Geochemistry & Geophysics
C-T Liu, Y-S He
Summary: From 3.0 to 2.7 billion years ago, the chemical composition of globally continental mafic volcanic rocks gradually decreased, indicating the gradual rise of major subaerial landmasses. This process was controlled by a dynamic balance of mountain building processes dominantly driven by plate tectonics and subsidence due to weathering erosion and thermal relaxation.
GEOCHEMICAL PERSPECTIVES LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Hugo Moreira
Summary: The analysis of mineral inclusions in magmas indicates significant changes in the oxidation state of sulfur before and after the Great Oxidation Event. These changes are attributed to the recycling of sediments altered by atmospheric events at the Earth's surface into the mantle.
Article
Geosciences, Multidisciplinary
Anfisa V. Skoblenko, Kirill E. Degtyarev, Nadezhda A. Kanygina, Andrey A. Tretyakov, Sergey Yu Skuzovatov, Kwan-Nang Pang, Hao-Yang Lee
Summary: The Precambrian metamagmatic complexes in the Zhingeldy and Kendyktas blocks of the Zheltau and ChuKendyktas terranes are composed of predominantly Neoproterozoic orthogneisses and subordinate metamorphic rocks. The presence of Precambrian metavolcanic rocks and metasedimentary complexes in the region further indicate the evolution and composition of the studied terranes. The findings also help with the correlation of metamorphic complexes in the SW part of the Central Asian Orogenic Belt.
Article
Geochemistry & Geophysics
Yoshiki Kanzaki, Ilya N. Bindeman
Summary: The use of oxygen isotope ratios in geological media has been important for understanding Earth's climate history. This study focuses on the limitations of using the delta O-18 record to estimate paleo-temperatures and explores the role of continental weathering and hydrothermal alteration in shaping the isotopic composition of ancient oceans. By utilizing reactive-transport models, the study demonstrates that Precambrian oceans may have been depleted in O-18, suggesting a different climate scenario than previously assumed.
Article
Geochemistry & Geophysics
Zhendong Tian, Bernd Lehmann, Changzhou Deng, Anbo Luo, Xingchun Zhang, Frederic Moynier, Runsheng Yin
Summary: This study reports the Hg isotopic compositions of granitic rocks and metasedimentary enclaves from the South China Craton. The results show different isotopic compositions for different types of granites, suggesting significant isotopic fractionation during magmatic processes. By combining with previously published data, the Hg abundance and isotopic composition of the upper continental crust are estimated to be higher than that of the primitive mantle.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Review
Ecology
J. William Schopf
Summary: Darwin's theory of evolution faced disputes for 50 years until early fossil records were discovered in the early 20th century, providing insights into life before the Cambrian period. With breakthrough advances in the 1950's and the contributions of the Precambrian Paleobiology Research Group, significant progress has been made in understanding the early evolution of life, although many unsolved problems remain.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2021)
Article
Geochemistry & Geophysics
Madeleine E. Murphy, Paul S. Savage, Nicholas J. Gardiner, Anthony R. Prave, Richard M. Gaschnig, Roberta L. Rudnick
Summary: By analyzing the silicon isotope composition of glacial diamictites from different geological ages, researchers have established the long-term secular record of the compositional evolution of upper continental crust. The study shows that the variability of silicon isotopes in diamictites decreases over time, indicating the diminishing importance of glacially milled banded iron formation and tonalite-trondhjemite-granodiorites in post-Archaean continental crust. The research also suggests that the upper continental crust becomes increasingly homogeneous through atmospheric oxygenation and crustal reworking.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Ze-Zhou Wang, Sheng-Ao Liu, Roberta L. Rudnick, Fang-Zhen Teng, Shui-Jiong Wang, Stephen E. Haggerty
Summary: The study examines the zinc isotopic compositions of eclogites from the Koidu kimberlite complex in Sierra Leone, providing insights into the origins of cratonic eclogites. The results suggest that low-MgO eclogites originate from altered oceanic crustal protoliths that underwent isotopic exchange with carbonates during subduction, while high-MgO eclogites are formed through metasomatic overprinting of low-MgO eclogites. Zinc isotopes offer a viable means to trace carbonate recycling in the mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Richard M. Gaschnig, Mary F. Horan, Roberta L. Rudnick, Jeffrey D. Vervoort, Christopher M. Fisher
Summary: The diamictites produced by continental glaciations were deposited in several geological periods and continents, with each period showing varying sources and crustal compositions. The study revealed different characteristics and origins for diamictites from different geological time periods and regions.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
Madeleine E. Murphy, Paul S. Savage, Nicholas J. Gardiner, Anthony R. Prave, Richard M. Gaschnig, Roberta L. Rudnick
Summary: By analyzing the silicon isotope composition of glacial diamictites from different geological ages, researchers have established the long-term secular record of the compositional evolution of upper continental crust. The study shows that the variability of silicon isotopes in diamictites decreases over time, indicating the diminishing importance of glacially milled banded iron formation and tonalite-trondhjemite-granodiorites in post-Archaean continental crust. The research also suggests that the upper continental crust becomes increasingly homogeneous through atmospheric oxygenation and crustal reworking.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Laura G. Sammon, William F. McDonough, Walter D. Mooney
Summary: This study provides a global assessment of the abundance of major oxides in the deep continental crust, using a combination of geochemistry and seismology. The study improves our understanding of the composition, evolution, and physical properties of the middle and lower continental crust, and presents a framework for building crustal models with multidisciplinary constraints on composition.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
X. -M. Liu, R. M. Gaschnig, R. L. Rudnick, R. M. Hazen, A. Shahar
Summary: The study found that the Fe isotopic composition of diamictites serves as proxies of the average upper continental crust and indicates a relatively constant Fe isotope composition throughout Earth history. The data suggest that chemical weathering is not important in producing variations in Fe isotopes in the upper continental crust.
GEOCHEMICAL PERSPECTIVES LETTERS
(2022)
Article
Geochemistry & Geophysics
Francisco E. Apen, Roberta L. Rudnick, Dmitri A. Ionov, John M. Cottle, Jean-Francois Moyen, Alexander Golovin, Andrey Korsakov
Summary: Coupled U-Pb and trace-element analyses of crustal xenoliths from the Siberian craton reveal the temperature and heat production of the lower crust during kimberlite eruption. The study shows that the U-Pb dates of rutile and apatite in the lower-crustal garnet granulites extend from 1.8 billion years to 360 million years, contrasting with the solely Paleoproterozoic apatite found in upper-crustal tonalites and amphibolites. The data suggest that the lower crust experienced neocrystallization and re-heating less than 1 million years before the eruption, indicating a cooler long-term ambient lower-crustal temperature. The xenolith data imply low crustal heat production for the Siberian craton but also suggest that the surface heat flow measurements may be inaccurate.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(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
Geochemistry & Geophysics
Peng-Yuan Han, Roberta L. Rudnick, Tao He, Michael A. W. Marks, Shui-Jiong Wang, Richard M. Gaschnig, Zhao -Chu Hu
Summary: The continental crust is an important reservoir for halogen elements, but their concentrations remain poorly known, hindering our understanding of the crust's role in Earth's halogen cycle.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Aleisha C. Johnson, Zhe J. Zhang, Nicolas Dauphas, Roberta L. Rudnick, John D. Foden, Magali Toc
Summary: The isotopic compositions of titanium and iron in lavas and mineral separates from Rindjani Volcano in Indonesia show lower isotopic fractionations compared to other differentiation suites. This is attributed to the dominance of low-Ti magnetite and clinopyroxene as carriers of titanium in Rindjani lavas. The high Fe3+/Fe2+ ratio in calc-alkaline magmas like Rindjani leads to decreased titanium isotopic fractionation. Similarly, negligible iron isotopic fractionation is observed in Rindjani rocks and minerals due to their oxidized nature and similar Fe3+/Fe2+ ratios. Paired titanium and iron isotopic analyses can be a powerful tool for assessing oxygen fugacity during differentiation.
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
Multidisciplinary Sciences
Shengyu Tian, Xin Ding, Yuhan Qi, Fei Wu, Yue Cai, Richard M. Gaschnig, Zicong Xiao, Weixin Lv, Roberta L. Rudnick, Fang Huang
Summary: The transition from mafic to felsic upper continental crust (UCC) is significant for the evolution of Earth and its inhabitants. V isotope ratios (δV-51) can provide insights into this transition. The δV-51 values of glacial diamictites from Archean to Paleozoic show that the UCC was dominantly mafic around 3 Ga but became felsic after that time.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Geochemistry & Geophysics
Nikitha S. Saji, Roberta L. Rudnick, Richard M. Gaschnig, Marc-Alban Millet
Summary: Titanium isotopes in glacial diamictites from the Paleoproterozoic Nuna and the Neoproterozoic Gondwana supercontinents indicate that the upper continental crust became more felsic during the collision of these supercontinents. The collisional mountain-building of Nuna and Gondwana likely increased the supply of nutrients from continents to oceans. This enhanced nutrient supply may have played a role in the development of organismal complexity and ecological expansion during the Neoproterozoic.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Wenshuai Li, Ryoichi Nakada, Yoshio Takahashi, Richard M. Gaschnig, Yongfeng Hu, Mohsen Shakouri, Roberta L. Rudnick, Xiao-Ming Liu
Summary: This study investigates the secular change in the geochemical composition of cerium in the upper continental crust (UCC) for tracing oxidative weathering. The results show that there are no distinguishable secular changes in the cerium anomaly and stable isotope composition of the average UCC. The study emphasizes the importance of utilizing the valence state of cerium as a reliable indicator of redox conditions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Sarah M. Aarons, Nicolas Dauphas, Nicolas D. Greber, Mathieu Roskosz, Julien Bouchez, Tamara Carley, Xiao-Ming Liu, Roberta L. Rudnick, Jerome Gaillardet
Summary: Stable Ti isotopes have been used to reconstruct the composition of Earth's continental crust. This study investigates the influence of provenance, physical, and chemical weathering on the composition of sediments. The results show that chemical weathering and sediment sorting impact Ti isotopic compositions, but the crustal protolith composition and sorting have a stronger effect than chemical weathering.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Multidisciplinary Sciences
Sheng-Ao Liu, Roberta L. Rudnick, Wen-Ran Liu, Fang-Zhen Teng, Tian-Hao Wu, Ze-Zhou Wang
Summary: Using copper isotopes, this study reveals that the formation of the continental crust involves the removal of isotopically light copper during the differentiation of mantle-derived magmas and the sinking of sulfide-rich mafic cumulates, resulting in a copper-depleted and isotopically heavy continental crust.
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)