Article
Geochemistry & Geophysics
J. T. Middleton, A. Paytan, M. Auro, M. A. Saito, T. J. Horner
Summary: The isotope composition of barium (Ba) in barite (BaSO4) is a powerful tool for tracing the cycles of pelagic Ba, carbon, and sulfur. This study analyzed the Ba isotope composition of porewaters and co-located BaSO4 in sediments from the Equatorial Pacific, and conducted laboratory experiments to assess the rates of Ba isotope alteration. The results suggest that ion exchange occurs in Equatorial Pacific sediments, and this process drives the observed Ba isotope offsets between pelagic BaSO4 and porewaters.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Jack G. Murphy, Anne-Sofie C. Ahm, Peter K. Swart, John A. Higgins
Summary: The records of lithium isotopic composition in seawater preserved in shallow-marine carbonate sediments are valuable for studying the links between silicate weathering, clay formation, global carbon cycle, and Earth's climate over geological time. This study presents measurements of lithium isotopic composition in Neogene shallow-marine carbonates and demonstrates the effects of mineralogy and diagenetic alteration on the variability of bulk sediment δ Li-7 values. The findings suggest that robust 'snapshots' of seawater δ Li-7 values in the past can be obtained from shallow-water marine carbonate sediments.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Eva L. Scheller, Miquela Ingalls, John M. Eiler, John P. Grotzinger, Uri Ryb
Summary: Through heating experiments of MHC, the researchers found that the stable isotopic compositions of ikaite pseudomorphs can be used for paleoclimate reconstruction, providing information about water temperature, δ18O(CARB), δ18O(fluid), and δ13C(CARB) which are influenced by dehydration diagenetic effects.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geology
Megan E. Smith, Peter K. Swart
Summary: The global correlation of negative excursions in delta C-13 values can be used to interpret major environmental changes, but diagenetic processes can affect these correlations.
SEDIMENTARY GEOLOGY
(2022)
Article
Geography, Physical
G. E. Jardine, A. J. Crocker, I Bailey, M. J. Cooper, J. A. Milton, P. A. Wilson
Summary: Climate projections suggest increasing frequency and duration of droughts in the North American Southwest (NASW) over the 21st century due to human-induced warming. Geological records can provide insights into past climate events to help predict future trends accurately.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geochemistry & Geophysics
Daisuke Araoka, George J. Simandl, Suzanne Paradis, Toshihiro Yoshimura, Mihoko Hoshino, Yoshiaki Kon
Summary: The Rock Canyon Creek REE-F-Ba deposit in British Columbia, Canada, is a carbonate-hosted REE deposit with similarities to nearby Mississippi Valley-type deposits. This study investigates the dolomitization and mineralization processes using isotopic and elemental compositions of carbonate minerals. The results suggest that the dolomite in the mineralized zone interacted with a low-temperature hydrothermal fluid and that the formation of the deposit involved re equilibration of marine-evaporitic dolomite with basinal fluids followed by infiltration of carbohydrothermal REE-bearing fluids.
JOURNAL OF GEOCHEMICAL EXPLORATION
(2022)
Article
Geochemistry & Geophysics
Ni Su, Shouye Yang, Kai Deng, Yuan-Pin Chang, Juan Xu, Zhouyang Wu
Summary: Small mountainous rivers in subtropical Taiwan supply large quantities of suspended and dissolved materials to the ocean, reflecting the high denudation rates in their elemental and isotopic compositions of river water and sediment.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Environmental Sciences
Heitor Evangelista, Claudio de M. Valeriano, Gabriel Paravidini, Sergio J. Goncalves Junior, Eduardo D. Sodre, Carla C. A. Neto, Elaine A. Santos, Newton de M. Neto, Caroline Peixoto, Marcus V. V. J. Licinio, Joselito N. Ribeiro, Araceli Flores, Madson G. Pereira, Catia F. Barbosa, Joao R. C. de Barcellos, Bruno V. X. de Oliveira, Flavia Guebert, Fabio Negrao, Marcelino J. dos Anjos, Ramon Silva Santos, Jose Carlos Seoane, Renato Campello Cordeiro, Monica Heilbron
Summary: The Abrolhos bank is home to a rich coral reef system in the Southwestern Atlantic, but is facing challenges from marine heat waves and anthropogenic interventions. The collapse of the Fundao mining tailings dam in 2015 led to a significant influx of slurry into the Doce River, impacting sedimentation in the Abrolhos bank.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geochemistry & Geophysics
Sean J. Loyd, Marissa N. Smirnoff
Summary: The importance of different diagenetic pathways in the formation of authigenic carbonate (AC) was studied, and it was found that anaerobic oxidation of methane (AOM) may be the most significant pathway. The impact of AOM on marine carbon budgets was evaluated.
Article
Geochemistry & Geophysics
Roger N. Bryant, Theodore M. Present, Anne-Sofie C. Ahm, Harry-Luke O. McClelland, Dan Razionale, Clara L. Blattler
Summary: This study examines the environmental factors driving early marine cementation in the Capitan Reef Complex in West Texas using stable isotope patterns. The results suggest that microbial sulfate reduction and recrystallization of carbonate phases were spatially and temporally coincident, leading to the incorporation of enriched sulfur isotopes in diagenetic calcite. The study also reveals that local diagenetic conditions influenced the extent of sulfur isotopic enrichment in carbonates compared to seawater. Additionally, the sulfate concentration in the Delaware Basin may have been lower during the Permian, resulting in more extensive isotopic evolution during carbonate recrystallization.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Simon Hohl, Sebastian Viehmann
Summary: Understanding the origin and evolution of life on Earth, as well as potentially on other planets in our solar system, is fundamental for humanity. Microbial communities have evolved over the longest period in Earth's history. Stromatolites, ancient lithified microbial mats, hold the key to understanding the evolution of microbial life on Earth and provide insights for planetary studies.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Andreas Wittke, Nikolaus Gussone, Dominik Derigs, Barbara M. A. Teichert
Summary: Fluid flow and carbonate recrystallization rates in deep-sea sediments from the Equatorial Eastern Pacific were studied. The results showed that the flow of seawater-like fluid into the sediment is influenced by the age of the oceanic crust and sediment cover. Carbonate recrystallization processes enrich the pore water with Ca-40, and after a time of carbonate recrystallization and cooling of the oceanic crust, seawater-like fluid starts to move upward through the sedimentary column, enriching the pore water with Ca-44. The findings have important implications for understanding sedimentation processes and geochemical cycles.
GEO-MARINE LETTERS
(2022)
Article
Geology
Cecilia B. Sanders, John C. Eiler, John P. Grotzinger
Summary: This study provides a paragenetic framework for phosphatic and non-phosphatic lithofacies of the Salitre Formation and reveals that the primary differences in porewater biogeochemistry may be the main mechanism controlling the distribution of phosphate and non-phosphate cements. Therefore, this study suggests that the ecology of the Ediacaran seafloor controlled the style and quality of mineralization observed today, and the presence of CFA cements in these rocks represents a unique taphonomic window for select microbial communities.
SEDIMENTARY GEOLOGY
(2023)
Article
Geochemistry & Geophysics
Pengfei Di, Niu Li, Shanggui Gong, Joern Peckmann, Shuhong Wang, Duofu Chen, Wen Yan
Summary: This study investigates the resilience of carbonate-associated sulfate (CAS) isotopic signatures in reef carbonates, providing new insights for the reconstruction of ancient seawater sulfate sulfur and oxygen isotopes. The results indicate that reef carbonates can faithfully record changes in coeval seawater sulfur isotopes, regardless of diagenetic alteration, including dolomitization. However, the oxygen isotope composition of CAS is more susceptible to alteration during diagenesis.
Article
Geochemistry & Geophysics
Philip T. Staudigel, John A. Higgins, Peter K. Swart
Summary: This study utilized a numerical model and various isotope measurement techniques to investigate the changes in fluid advection rates over time, revealing a significant shift in the relative contributions of different mechanisms governing fluid flow around 13 million years ago.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Marcus Gutjahr, Louise Bordier, Eric Douville, Jesse Farmer, Gavin L. Foster, Ed C. Hathorne, Barbel Honisch, Damien Lemarchand, Pascale Louvat, Malcolm McCulloch, Johanna Noireaux, Nicola Pallavicini, James W. B. Rae, Ilia Rodushkin, Philippe Roux, Joseph A. Stewart, Francois Thil, Chen-Feng You
Summary: The study focused on analyzing boron isotopes in marine carbonates, with an emphasis on evaluating the influence of oxidative pre-treatment and analytical approaches on the results, and providing consistent boron isotope compositions for two carbonate materials.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Lisa Bretschneider, Ed C. Hathorne, Huang Huang, Julia Luebbers, Karlos G. D. Kochhann, Ann Holbourn, Wolfgang Kuhnt, Rasmus Thiede, Daniel Gebregiorgis, Liviu Giosan, Martin Frank
Summary: The study suggests that contributions from different erosional sources to the Bay of Bengal remained consistent during the middle to late Miocene period, despite major tectonic reorganizations in the Himalayas. However, on orbital timescales, there were marked fluctuations in all three isotope systems, especially during the Miocene Climatic Optimum and major global cooling periods.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Geochemistry & Geophysics
H. Huang, M. Gutjahr, G. Kuhn, Ed C. Hathorne, A. Eisenhauer
Summary: In order to reconstruct past ocean circulation and water mass mixing in the Southern Ocean, a brief 10-second leaching method was developed to extract reliable seawater Pb and Nd isotope signals from sediments in the Atlantic sector. This method proved to be more efficient and accurate compared to traditional 30-minute leaching approaches, as validated by direct comparisons with actual seawater, porewater, and sediment leachates at three stations near the Antarctic Filchner-Ronne Ice Shelf.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geosciences, Multidisciplinary
Zhimian Cao, Xinting Rao, Yang Yu, Christopher Siebert, Ed C. Hathorne, Bo Liu, Guizhi Wang, Ergang Lian, Zhibing Wang, Ruifeng Zhang, Lei Gao, Gangjian Wei, Shouye Yang, Minhan Dai, Martin Frank
Summary: The study reveals significant barium isotope fractionation at near-zero salinities in the Yangtze and Pearl River Estuary, with conservative mixing dominating delta Ba-138(DBa) distributions beyond low salinities. This provides a modern calibration for using barium isotopes as a proxy for paleosalinity and river water inputs into the ocean.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Bruce L. A. Charlier, Francois L. H. Tissot, Hauke Vollstaedt, Nicolas Dauphas, Colin J. N. Wilson, Ren T. Marquez
Summary: Experimental results on CAIs from the Allende meteorite suggest that extreme Sr-84 anomalies may be caused by the presence of a presolar carrier enriched in the p-nuclide Sr-84. This discovery reinstates the chronological significance of differences in initial Sr-87/Sr-86 ratios between CAIs and volatile-depleted inner solar system materials.
Article
Environmental Sciences
Kristin Doering, Claudia Ehlert, Katharina Pahnke, Martin Frank, Ralph Schneider, Patricia Grasse
Summary: The study compared the silicon isotope characteristics of different radiolarian taxa and sediment samples from different depths off the coast of Peru, revealing their relationship with dissolved silicic acid concentrations and providing insights into the potential use of radiolarian silicon isotopes in paleo reconstructions.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Lisa Bretschneider, Ed C. Hathorne, Clara T. Bolton, Daniel Gebregiorgis, Liviu Giosan, Emmeline Gray, Huang Huang, Ann Holbourn, Wolfgang Kuhnt, Martin Frank
Summary: Research found that at 7.3 million years ago, there was a change in monsoon intensity in the South Asian Monsoon domain, with an increased contribution from the Irrawaddy River to sediment. This change was likely the result of global cooling and increasing aridity leading to an eastward shift in precipitation patterns.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Geochemistry & Geophysics
Filip Scheiner, Lukas Ackerman, Katarina Holcova, Jan Rejsek, Hauke Vollstaedt, Jana Durisova, Vaclav Santolik
Summary: The Nd-143/Nd-144 isotopic composition of foraminifera is a useful proxy for tracing specific water masses in paleoceanographic studies, but its applicability is limited by the amount of material needed for analysis. In this study, we analyzed foraminiferal samples weighing only 300-500 μg and showed that even very low Nd loads can yield precise results. We also found significant naturally induced Nd isotopic variability among different foraminiferal species.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Yang Yu, Ed Hathorne, Christopher Siebert, Thomas Felis, C. P. Rajendran, Martin Frank
Summary: A stable Ba isotope record of a young fossil coral from the Andaman Islands in the Indian Ocean provides insights into environmental variability before the industrial era. The record shows seasonal variability during the South Asian summer monsoon and post-monsoon seasons, with spikes observed during the dry seasons. The study establishes a link between monsoon-driven freshening events and Ba isotope variability in coastal oceans.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Alexandra Filippova, Martin Frank, Markus Kienast, Marcus Gutjahr, Ed C. Hathorne, Claude Hillaire-Marcel
Summary: Constraints on deep-water production in the Labrador Sea complicate reconstructions of the AMOC during the Late Quaternary. Detrital carbonates deposited in the Labrador Sea affect Nd isotope signatures. Nd isotope compositions of deep and intermediate waters were analyzed. During the Last Glacial Maximum, the Nd isotope signatures in the Labrador Sea showed active water mass mixing with radiogenic values prevailing in the eastern part and less radiogenic values in the western slope. The deposition of detrital carbonates during Heinrich stadials was accompanied by negative detrital and authigenic Nd isotope excursions likely controlled by dolostone dissolution. The Holocene authigenic Nd signatures approached modern bottom water mass signatures.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Geochemistry & Geophysics
Zhimian Cao, Xinting Rao, Yating Li, Qingquan Hong, Lin Wei, Yang Yu, Claudia Ehlert, Bo Liu, Christopher Siebert, Ed C. Hathorne, Zhouling Zhang, Florian Scholz, Sabine Kasten, Martin Frank
Summary: The development of stable barium (Ba) isotope measurements provides a novel tool to investigate the geochemical cycling of Ba in the ocean and its sediments. Pore water profiles of dissolved stable Ba isotopic signatures (delta Ba-138(pw)) from shallow water sediments covering the entire Pearl River Estuary (PRE) in Southern China showed depth-dependent variations indicating preferential removal of low-mass Ba isotopes from the pore water during solution-solid phase interactions.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Environmental Sciences
Zhouling Zhang, Yang Yu, Ed C. Hathorne, Lucia H. Vieira, Patricia Grasse, Christopher Siebert, Peer Rahlf, Martin Frank
Summary: The correlation between dissolved barium (dBa) and silicon (dSi) concentrations in the modern ocean supports the use of Ba as a paleoceanographic proxy. However, the mechanisms behind their linkage and the processes controlling oceanic Ba cycling remain unclear. This study investigates the behavior of Ba and Si at the Congo River-dominated Southeast Atlantic margin, revealing different mechanisms controlling their biogeochemical cycling and highlighting the influence of the margin on marine Ba cycling.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Multidisciplinary Sciences
Antao Xu, Ed Hathorne, Georgi Laukert, Martin Frank
Summary: The isotopic signatures of Nd and Hf in the Amazon River estuary are influenced by the nearby Para River. The Para River supplies dissolved trace metals to the estuary and ocean. It is found that the changes in Nd and Hf concentrations across the estuary are due to the admixture of high-concentration Nd and Hf from the Para River.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Cecile L. Blanchet, Rik Tjallingii, Anja M. Schleicher, Stefan Schouten, Martin Frank, Achim Brauer
Summary: Ocean deoxygenation poses a rising threat to marine ecosystems and food resources under current climate warming conditions. This study reconstructs changes in oxygen levels using sediment cores from the Mediterranean Sea, revealing seasonal sedimentation and dynamic past oxygenation conditions. Rapid fluctuations in oxygenation conditions above the Nile deep-sea fan in the past 10,000 years were discovered, highlighting the impact of runoff-driven eutrophication on rapid oxygenation changes in the south-eastern Levantine Basin.
CLIMATE OF THE PAST
(2021)
Article
Geochemistry & Geophysics
Xinze Lu, Geoffrey J. Gilleaudeau, Brian Kendall
Summary: The Late Ordovician mass extinction is the first major extinction event in the Phanerozoic, but the reasons for the decline in global biodiversity before the extinction are not well understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
Article
Geochemistry & Geophysics
Junyao Kang, Daniel D. Gregory, Benjamin Gill, Shiqiang Huang, Changxin Lai, Zhaoshan Chang, Huan Cui, Ivan Belousov, Shuhai Xiao
Summary: Sedimentary pyrite is an important geological archive, but it can be altered by diagenetic and hydrothermal processes. This study successfully trained machine learning algorithms to distinguish pyrite origins using trace element data. The approach was validated and applied to identify the origins of pyrite in two sedimentary successions in South China.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)