Article
Geochemistry & Geophysics
Jin Luo, Xiaoping Long, Fred T. Bowyer, Benjamin J. W. Mills, Jie Li, Yijun Xiong, Xiangkun Zhu, Kan Zhang, Simon W. Poulton
Summary: The study suggests that the early Mesoproterozoic oceans experienced pulsed oxygenation events, leading to overall progressive oxygenation. While deep water sediments recorded the maximum oxygenation depth during early oxygenation events, shallower water sediments more accurately reflected the Mo isotopic composition of coeval seawater.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Paul Bridger, Simon W. Poulton, Ying Zhou, Chao Li, Kun Zhang, Graham A. Shields
Summary: This study reveals fluctuating redox conditions in the lagoonal area of the Yangtze platform during the late Ediacaran period, suggesting that low-oxygen environments may have restricted the distribution of aerobic fauna.
GEOLOGICAL MAGAZINE
(2022)
Article
Geography, Physical
Benjamin C. Gill, Tais W. Dahl, Emma U. Hammarlund, Matthew A. LeRoy, Gwyneth W. Gordon, Donald E. Canfield, Ariel D. Anbar, Timothy W. Lyons
Summary: The study revealed widespread oxygen deficiency in the early Paleozoic deep oceans. It also identified significant changes in marine redox conditions in certain regions during the late Cambrian, linked to the SPICE event.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geography, Physical
M. Alam, M. Tripti, G. P. Gurumurthy, Y. Sohrin, M. Tsujisaka, A. D. Singh, S. Takano, K. Verma
Summary: The study investigates the oxygenation history of the northeastern Arabian Sea since the late Miocene using redox sensitive elemental and metal stable isotopic signatures in deep-sea sediments. The results indicate varying oxygenation conditions in the water column during different periods.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geochemistry & Geophysics
Wenhan Chen, David B. Kemp, Tianchen He, Robert J. Newton, Yijun Xiong, Hugh C. Jenkyns, Kentaro Izumi, Tenichi Cho, Chunju Huang, Simon W. Poulton
Summary: The period from the late Pliensbachian to early Toarcian experienced significant climatic and environmental changes, including the occurrence of the early Toarcian Oceanic Anoxic Event (T-OAE) and the Pliensbachian-Toarcian boundary event (Pl/To). Current knowledge of seawater redox conditions during this time is mainly based on European sections deposited in restricted basins, limiting our understanding of the redox evolution in the open ocean, particularly Panthalassa. This study presents Fe-speciation and redox-sensitive trace metal data from two Panthalassic Ocean sections, revealing anoxic-ferruginous conditions in the deep-water site and oxygenated to suboxic conditions in the shallow margin site. The observations suggest that upwelling of anoxic-ferruginous waters onto the shelf, driven by increased sea level and prevailing winds, led to Fe2+ oxidation in the oxygenated shallow waters.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Environmental Sciences
Luis M. Laglera, Hema Uskaikar, Christine Klaas, S. Wajih A. Naqvi, Dieter A. Wolf-Gladrow, Antonio Tovar-Sanchez
Summary: The redox speciation of iron was investigated during the iron fertilization LOHAFEX by comparing chemiluminescence assays of filtered and unfiltered samples. It was found that higher chemiluminescence in unfiltered samples may be attributed to Fe(II) adsorbed onto biological particles. The study also showed that dissolved and particulate Fe(II) increased initially and then decreased back to initial levels during LOHAFEX. The chemiluminescence analysis revealed strong gradients in unfiltered samples, which were significantly correlated to biomass and photosynthetic efficiency, suggesting biological control.
MARINE POLLUTION BULLETIN
(2022)
Article
Geography, Physical
Chelsie N. Bowman, Theodore R. Them, Marisa D. Knight, Dimitri Kaljo, Mats E. Eriksson, Olle Hints, Tonu Martma, Jeremy D. Owens, Seth A. Young
Summary: The Silurian period was marked by significant climatic and sea level changes, biotic crises, and carbon cycle volatility. Research on late Silurian has focused on global marine redox conditions, but this study examines variability in local paleo-redox conditions using paleo-redox proxies in carbonate and clastic sequences from Sweden and Latvia. The results show that the sediments in both locations were influenced by different levels of oxygen deficiency, with sediments on the deep shelf deposited in a denitrifying water column before and during the carbon isotope excursion event.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Baozeng Xie, Jian-ming Zhu, Xiangli Wang, Dongtao Xu, Limin Zhou, Xiqiang Zhou, Xiaoying Shi, Dongjie Tang
Summary: The availability of oxygen is crucial for the evolution of eukaryotes, but the redox conditions of the mid-Proterozoic atmospheric-oceanic system are debated. Previous studies suggested a low oxygen level in the mid-Proterozoic atmosphere, but a recent study revealed a pulsed oxygenation event associated with the earliest known multi-cellular eukaryotic fossils.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2023)
Article
Geochemistry & Geophysics
Geoffrey J. Gilleaudeau, Thomas J. Algeo, Timothy W. Lyons, Steven Bates, Ariel D. Anbar
Summary: The study examines the reconstruction of watermasses in an ancient epeiric sea, focusing on redox state and salinity variations related to water depth and geography. Iron speciation and trace metal abundances reveal a strong paleoredox gradient and a subtle paleosalinity gradient across the Appalachian Basin, shedding light on ancient oceanic conditions.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Geoffrey J. Gilleaudeau, Wei Wei, Mariano N. Remirez, Yi Song, Timothy W. Lyons, Steven Bates, Ariel D. Anbar, Thomas J. Algeo
Summary: This study presents a reconstruction of watermass evolution in the Late Devonian Appalachian Seaway of North America. The authors use proxies for sediment supply, paleosalinity, paleoredox, and basin hydrography to understand the environmental conditions. They find cyclic changes in sedimentation, redox, and salinity near the Catskill Delta, as well as distinct watermass signatures in the lower and upper Cleveland Shale.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Review
Chemistry, Analytical
Katja Schmidt, Sophie A. L. Paul, Eric P. Achterberg
Summary: The geochemical behavior and bioavailability of trace metals are closely linked to their physical fractionation and chemical speciation. The DGT speciation technique allows for the challenging assessment of labile concentrations of various trace metals in ocean waters. This study demonstrates the applicability and sensitivity of DGT passive samplers for monitoring anthropogenic activities and studying natural processes in deep-sea environments.
TRAC-TRENDS IN ANALYTICAL CHEMISTRY
(2022)
Article
Environmental Sciences
Alessandro Tagliabue, Andrew R. Bowie, Thomas Holmes, Pauline Latour, Pier van der Merwe, Melanie Gault-Ringold, Kathrin Wuttig, Joseph A. Resing
Summary: Hydrothermal iron supply plays an important role in the Southern Ocean carbon cycle. The magnitude of its impact on export production depends on the estimation method used, with inverse helium modelling leading to a significant reduction. However, the observed anomalies and correlation with observations suggest that the spreading rate input scheme is more accurate.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Seth G. John, Rachel L. Kelly, Xiaopeng Bian, Feixue Fu, M. Isabel Smith, Nathan T. Lanning, Hengdi Liang, Benoit Pasquier, Emily A. Seelen, Mark Holzer, Laura Wasylenki, Tim M. Conway, Jessica N. Fitzsimmons, David A. Hutchins, Shun-Chung Yang
Summary: The study investigates the biogeochemical cycle of nickel in the oceans, revealing the distribution characteristics and influencing factors of oceanic nickel through a combination of experiments and simulations.
Article
Geochemistry & Geophysics
Minming Cui, Maya Gomes
Summary: The concentrations and isotopic signatures of molybdenum and tungsten are widely used to study changes in ocean redox conditions. Experimental results show that manganese oxide greatly catalyzes the hydrolysis of thiomolybdate and thiotungstate. Crystal structure differences of manganese oxides and solution pH and ionic strength have limited impacts on the hydrolysis rates of molybdenum and tungsten thioanions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geography, Physical
Satoshi Takahashi, Rie S. Hori, Satoshi Yamakita, Yoshiaki Aita, Atsushi Takemura, Minoru Ikehara, Yijun Xiong, Simon W. Poulton, Paul B. Wignall, Takaaki Itai, Hamish J. Campbell, Bernard K. Sporli
Summary: The end-Permian mass extinction (EPME) has been linked with the widespread development of oxygen-poor oceanic conditions. The study suggests that euxinic conditions were widespread in low-latitude regions of the Panthalassan ocean, and ocean anoxia gradually expanded from low to middle-high latitude regions during the Permo-Triassic transition. Ocean anoxia during the EPME coincides with extreme climate warming and the associated effects were likely critical triggers for ocean deoxygenation.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geochemistry & Geophysics
Zhong Han, Xiumian Hu, Tianchen He, Robert J. Newton, Hugh C. Jenkyns, Robert A. Jamieson, Marco Franceschi
Summary: The Early Jurassic is an important interval characterized by global carbon-isotope perturbations. This study presents new stable sulfur-isotope data and reveals the relationship between sulfur and carbon isotopes, suggesting changes in pyrite burial. Modeling results indicate a possible decrease in oceanic sulfate concentration during the Sinemurian-Toarcian interval due to evaporite deposition and enhanced pyrite burial. Overall, this research enhances our understanding of long-term environmental and climatic changes during the Early Jurassic.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Jacopo Dal Corso, Benjamin J. W. Mills, Daoliang Chu, Robert J. Newton, Haijun Song
Summary: Past major biological turnovers are associated with large injections of CO2 into the atmosphere-ocean system, often related to the formation of Large Igneous Provinces. However, the effects of these CO2 pulses on ecosystems vary at different times, depending on the initial conditions. This study uses biogeochemical and climate modeling to show how delayed vegetation recovery and the amalgamation of Pangaea influenced the Late Triassic Carnian Pluvial Episode. The findings provide insights into the mechanisms behind this global climate change event and its connection to a major biological turnover and the emplacement of the Wrangellia LIP.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Bo Chen, Chunlin Hu, Benjamin J. W. Mills, Tianchen He, Morten B. Andersen, Xi Chen, Pengju Liu, Miao Lu, Robert J. Newton, Simon W. Poulton, Graham A. Shields, Maoyan Zhu
Summary: The Ediacaran Period was characterized by major carbon isotope perturbations, including anomalies similar to the Shuram/DOUNCE anomaly at 570 Ma and the WANCE anomaly at 610 Ma. These anomalies were associated with expansions in oxygenated seawater and environmental perturbations. New uranium isotope data, as well as strontium and sulfur isotope data, provide evidence of environmental changes during these anomalies.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geography, Physical
Manfredo Capriolo, Benjamin J. W. Mills, Robert J. Newton, Jacopo Dal Corso, Alexander M. Dunhill, Paul B. Wignall, Andrea Marzoli
Summary: Research has shown that CO2 emissions from CAMP volcanism during the end-Triassic period had a significant impact on global climate and environment, causing temperature increases and pH drops. Simulation results indicate that this volcanic activity may have alone led to climate change and environmental damage.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geochemistry & Geophysics
Germain Bayon, Ilya N. N. Bindeman, Anne Trinquier, Gregory J. Retallack, Andrey Bekker
Summary: The intensity of terrestrial weathering over the past 2.7 billion years has been reconstructed, revealing a link between chemical weathering and atmospheric oxygen levels. The study suggests that chemical weathering played a significant role in the expansion of the aerobic biosphere and the occurrence of the Great Oxidation Event.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geography, Physical
Tianchen He, Robert J. Newton, Paul B. Wignall, Stephen Reid, Jacopo Dal Corso, Satoshi Takahashi, Hepin Wu, Simona Todaro, Pietro Di Stefano, Vincenzo Randazzo, Manuel Rigo, Alexander M. Dunhill
Summary: During the end-Triassic mass extinction in the western Tethys, the shallow ocean experienced a significant decrease in oxygen levels, leading to oxygen-poor conditions for shallow-water organisms. Additionally, the expansion of deeper anoxic waters coincided with widespread anoxic deposition on continental shelves and slopes.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geography, Physical
Tianchen He, Paul B. Wignall, Robert J. Newton, Jed W. Atkinson, Jacob F. J. Keeling, Yijun Xiong, Simon W. Poulton
Summary: This study investigates the occurrence of marine anoxia in the Bristol Channel Basin and Larne Basin during the Triassic-Jurassic transition. The results show frequent development of anoxic-ferruginous conditions and ephemeral euxinic episodes in the Bristol Channel Basin, while the Larne Basin remained oxygenated. The second phase of the end-Triassic mass extinction coincided with persistent euxinic conditions in both basins. Post-extinction, anoxia persisted but did not extend into the shallowest areas where benthic marine ecosystem recovery was occurring.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geosciences, Multidisciplinary
Lewis J. Alcott, Benjamin J. W. Mills, Andrey Bekker, Simon W. Poulton
Summary: The rise of atmospheric oxygen during the Great Oxidation Event was a defining transition in the evolution of global biogeochemical cycles and life on Earth. The study suggests that the recycling of phosphorus driven by increasing oceanic sulfide availability contributed to the persistent oxygenation of Earth's atmosphere.
Article
Geography, Physical
Wenhan Chen, David B. Kemp, Robert J. Newton, Tianchen He, Chunju Huang, Tenichi Cho, Kentaro Izumi
Summary: This study analyzes the sulfur isotopes and pyrite sulfur concentrations of rock samples from Japan to understand the impact of the early Toarcian Oceanic Anoxic Event (T-OAE) on the sulfur cycle. The results show significant positive shifts in sulfur isotopes and sulfur concentrations, indicating increased export production, preservation, and sedimentation rates. These findings suggest a previously unrecognized perturbation to the deep-water sulfur cycle during the T-OAE.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geochemistry & Geophysics
Frantz Ossa Ossa, Jorge E. Spangenberg, Andrey Bekker, Stephan Koenig, Eva E. Stueken, Axel Hofmann, Simon W. Poulton, Aierken Yierpan, Maria Varas-Reus, Benjamin Eickmann, Morten B. Andersen, Ronny Schoenberg
Summary: This study investigates the marine shales deposited during the Lomagundi Event in the Paleoproterozoic era, providing evidence for a highly productive and well-oxygenated photic zone. However, a subsequent deoxygenation of the atmosphere-ocean system led to enhanced denitrification and reduction of selenium oxyanions. The findings suggest that oxygen levels in the atmosphere-ocean system during this period were much lower than modern concentrations.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Wenhan Chen, David B. Kemp, Tianchen He, Robert J. Newton, Yijun Xiong, Hugh C. Jenkyns, Kentaro Izumi, Tenichi Cho, Chunju Huang, Simon W. Poulton
Summary: The period from the late Pliensbachian to early Toarcian experienced significant climatic and environmental changes, including the occurrence of the early Toarcian Oceanic Anoxic Event (T-OAE) and the Pliensbachian-Toarcian boundary event (Pl/To). Current knowledge of seawater redox conditions during this time is mainly based on European sections deposited in restricted basins, limiting our understanding of the redox evolution in the open ocean, particularly Panthalassa. This study presents Fe-speciation and redox-sensitive trace metal data from two Panthalassic Ocean sections, revealing anoxic-ferruginous conditions in the deep-water site and oxygenated to suboxic conditions in the shallow margin site. The observations suggest that upwelling of anoxic-ferruginous waters onto the shelf, driven by increased sea level and prevailing winds, led to Fe2+ oxidation in the oxygenated shallow waters.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Zhong Han, Xiumian Hu, Robert J. Newton, Tianchen He, Benjamin J. W. Mills, Hugh C. Jenkyns, Micha Ruhl, Robert A. Jamieson
Summary: Researchers have studied high-resolution sulfur isotope records from the Tibetan Himalaya during the late Pliensbachian-Toarcian interval. They observed widespread ocean deoxygenation and significant spatial heterogeneity in seawater sulfur isotope compositions. Box-modeling analysis showed that the global reduction in seawater sulfate concentrations was responsible for the persistent positive sulfur isotope values in the later period.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Wei Shi, Benjamin J. W. Mills, Thomas J. Algeo, Simon W. Poulton, Robert J. Newton, Matthew S. Dodd, Zihu Zhang, Lei Zheng, Tianchen He, Mingcai Hou, Chao Li
Summary: Ediacaran carbonate rocks document the Shuram Excursion, the largest negative carbonate-carbon isotope excursion in Earth history. This event, attributed to enhanced weathering inputs of sulfate, has a complex interaction with the carbon-sulfur cycle, affecting the redox state of the ocean-atmosphere system and the co-evolution of life and the environment during the Ediacaran. High-resolution records of isotopes and phosphorus concentrations, combined with biogeochemical model simulations, indicate widespread H2S reoxidation during the Shuram Excursion, contributing to spatial heterogeneity in oceanic redox conditions and nutrient availability.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geosciences, Multidisciplinary
Yinggang Zhang, Tao Yang, Robert J. Newton, Wenqing Pan, Yongquan Chen, Huiyang Yu
Summary: The Cambrian period was a critical time in Earth's history, with the rapid diversification of early animals and significant changes in oceanic conditions. In this study, carbonate sediments from the Xingdi section in the eastern Tarim Basin were used to investigate the carbon and strontium isotope stratigraphy during the Cambrian. The carbon isotope record showed similarities to global seawater carbon isotope variations, providing a viable stratigraphic framework for the Cambrian strata in this region.
JOURNAL OF ASIAN EARTH SCIENCES
(2023)
Article
Ecology
Adam Woodhouse, Frances A. Procter, Sophie L. Jackson, Robert A. Jamieson, Robert J. Newton, Philip F. Sexton, Tracy Aze
Summary: The Pliocene-Recent period has witnessed significant climatic and paleoceanographic changes that have transformed the modern world. The closure of the Central American Seaway and the expansion of Northern Hemisphere ice sheets have globally impacted the structure of oceans, leading to the extinction and radiation of marine species. By examining sedimentary records from the Eastern Equatorial Pacific Ocean and global datasets, researchers have observed extinctions and dominance shifts in marine calcifying planktonic foraminifera, which are sensitive to water column structure and temperature gradients. These changes are associated with the closure of the Central American Seaway and the subsequent expansion of polar ice sheets, favoring cold- and deep-water species. These findings have implications for understanding the impact of anthropogenic climate change on modern marine plankton communities.