Article
Geography, Physical
Wanyi Lu, Catia F. Barbosa, Anthony E. Rathburn, Priscila da Matta Xavier, Anna P. S. Cruz, Ellen Thomas, Rosalind E. M. Rickaby, Yi Ge Zhang, Zunli Lu
Summary: A downcore comparison of benthic foraminiferal surface porosity and iodine to calcium ratio proxies in a core from the southern Brazilian margin suggests that bottom-water oxygen concentrations remained above 50 µmol/kg during the last 45 kyr. Further investigation into non-O2 factors influencing these proxies is required.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Review
Environmental Studies
Zhenyu Qin, Xuefeng Sun
Summary: China is a crucial region for studying the relationship between climate change and hominin evolution. Archaeological sites from the Early to Middle Pleistocene in China reveal that early human activities gradually shifted southward during multiple glacial-interglacial cycles, with frequent bidirectional movements between north and south during different periods.
Article
Geochemistry & Geophysics
Wanyi Lu, Yi Wang, Delia W. Oppo, Sune G. Nielsen, Kassandra M. Costa
Summary: Oceanic oxygen reconstructions of the last glacial period are crucial for understanding deep ocean carbon storage and validating climate model simulations. Existing reconstructions of bottom-water oxygen (BWO) are ambiguous, and we propose and evaluate three new proxies for BWO.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Robert K. Poirier, Madison Q. Gaetano, Kimberly Acevedo, Morgan F. Schaller, Maureen E. Raymo, Reinhard Kozdon
Summary: This study introduces the Foraminiferal Preservation Index (FPI) to quantify the degree of diagenesis in benthic foraminifera, highlighting deep-ocean water mass composition as a primary driver of diagenesis over time. Stable isotope data from foraminiferal tests of varying preservation quality suggest significant biases in geochemical proxy records used to reconstruct past climate changes.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Environmental Sciences
Thiago A. Sousa, Igor Martins Venancio, Eduardo Duarte Marques, Thiago S. Figueiredo, Rodrigo Azevedo Nascimento, Joseph M. Smoak, Ana Luiza S. Albuquerque, Claudio Morisson Valeriano, Emmanoel Vieira Silva-Filho
Summary: In this study, paleoredox conditions in the Western Equatorial Atlantic (WEA) during the glacial-interglacial cycle were reconstructed using high-resolution REEs data and anomalies. The results indicate that the Parnaiba River is the main source of REEs in the western South Atlantic, and changes in the negative Ce-anomaly suggest a reduction in deep ocean oxygenation during the interglacial period. Additionally, the origin of positive Eu anomalies in the core is attributed to preferential retention by feldspars.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Inda Brinkmann, Christine Barras, Tom Jilbert, K. Mareike Paul, Andrea Somogyi, Sha Ni, Magali Schweizer, Joan M. Bernhard, Helena L. Filipsson
Summary: Fjord systems are being increasingly affected by low-oxygen conditions, driven by ongoing global changes. Sedimentary records in fjords can provide valuable insights into the mechanisms and impacts of deoxygenation. However, these records can only be interpreted with well-calibrated proxies.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Geography, Physical
Victor M. Giraldo-Gomez, Maria Rose Petrizzo, Gabriele Gambacorta, Cinzia Bottini, Silvia E. Gilardoni, Elisabetta Erba
Summary: The benthic foraminiferal assemblages from the Scaglia Bianca Formation in Italy provide a detailed record of faunal changes during the Oceanic Anoxic Event 1d (OAE 1d). Integration of different proxies allows reconstruction of water conditions during this event. Prior to OAE 1d, stable mesotrophic conditions were observed. During OAE 1d, there was an increase in infaunal taxa suggesting mesotrophic conditions and hypoxic/anoxic conditions in bottom waters. After OAE 1d, there was a restoration of oxygen conditions and continued mesotrophic regime in bottom waters.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Stephanie Stainbank, Dick Kroon, Erica S. de Leau, Silvia Spezzaferri
Summary: Research indicates that under ancient climatic conditions, tropical ocean temperatures were slightly higher than modern times, with temperatures significantly higher during MIS11c, resembling the present-day phenomenon. Individual foraminiferal analysis during MIS11c shows frequent bleaching events, revealing the vulnerability of tropical marine organisms to future ocean temperature changes.
SCIENTIFIC REPORTS
(2021)
Article
Environmental Sciences
Yoshiyuki Ishitani, Caterina Ciacci, Yurika Ujiie, Akihiro Tame, Mattia Tiboni, Goro Tanifuji, Yuji Inagaki, Fabrizio Frontalini
Summary: Titanium dioxide nanoparticles (NPs) have diverse applications and are increasingly being used as an alternative to banned sunscreen filters. However, little is known about their toxicity mechanisms. This study investigates the cytotoxicity and detoxification mechanism of TiO2 NPs in marine benthic foraminifers. The findings reveal that the foraminifers can tolerate the toxicity of TiO2 NPs and prevent their further uptake by trapping them inside mucus. This previously unknown strategy could be useful for bioremediation and managing TiO2 pollution.
ENVIRONMENTAL POLLUTION
(2023)
Article
Geosciences, Multidisciplinary
Gerhard Schmiedl, Yvonne Milker, Andreas Mackensen
Summary: The biodiversity of deep-sea ecosystems is influenced by climate changes and resource availability. The diversity and species composition of benthic foraminifera serve as indicators of these changes. Highly diverse deep-sea ecosystems are more resilient to disturbances, while oligotrophic and well-ventilated ecosystems experience lower diversity due to seasonal pulses of phytodetritus.
EARTH-SCIENCE REVIEWS
(2023)
Article
Oceanography
Duo Wang, Xuan Ding, Franck Bassinot
Summary: The study conducted on foraminifera in the Indian Ocean U1446 site revealed a strong and varying dissolution phenomenon over the past 190 ka, despite its location well above the modern lysocline. There is a clear contrast in dissolution strength between different marine isotope stages, potentially impacting geochemical proxies measured on foraminifera. Further investigation is needed to understand the causes of such above-lysocline dissolution and its impact on foraminifera-based proxies for paleoenvironmental reconstruction.
ACTA OCEANOLOGICA SINICA
(2021)
Article
Environmental Sciences
Laura Tavera Martinez, Margarita Marchant, Praxedes Munoz, Roberto T. Abdala Diaz
Summary: This study reconstructed the ecological and environmental features of Mejillones Bay by studying benthic foraminifera, and the results showed significant differences between Mejillones Bay and other OMZs.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Amalia Prandekou, Maria Geraga, Helen Kaberi, Spyros Sergiou, Dimitris Christodoulou, George Ferentinos, Constantin Koutsikopoulos, George Papatheodorou
Summary: The study found that the degradation of bottom water in Amvrakikos Gulf has led to a decline in surface water quality, with different regions being affected by seawater intrusion or river discharge to varying degrees, which significantly impacts the environmental quality of bottom water.
MARINE POLLUTION BULLETIN
(2022)
Article
Oceanography
Xiaoyi Guo, Qinsheng Wei, Bochao Xu, William C. Burnett, Joan M. Bernhard, Haiming Nan, Ergang Lian, Shouye Yang, Zhigang Yu
Summary: The foraminifer C. subincertum in the Changjiang Estuary can serve as a proxy for dissolved oxygen variations, with Mn/Ca ratios in its tests reflecting changes in bottom water chemistry. Wider ranges of foraminiferal Mn/Ca occurred in summer, indicating more pronounced hypoxia conditions during that time.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Paleontology
Janika Joehnck, Ann Holbourn, Wolfgang Kuhnt, Nils Andersen
Summary: This study investigated the interspecies offsets of benthic foraminiferal oxygen isotope composition in different regions and found that epifaunal taxa are more reliable indicators for paleoclimatic reconstructions than infaunal taxa. The study also highlighted the influence of regional and temporal variations in organic carbon flux/degradation and dissolution of calcite on the amplitude of delta O-18 fluctuations.
JOURNAL OF FORAMINIFERAL RESEARCH
(2021)
Article
Microbiology
Roxana T. Shafiee, Joseph T. Snow, Svenja Hester, Qiong Zhang, Rosalind E. M. Rickaby
Summary: Dissolved iron levels are extremely low in the oceans, impacting the growth rates of specific ecological microorganisms. The proteomic response of ammonia-oxidising archaea to Fe limitation shows significant changes, with an increase in functional alternatives observed under Fe limitation. The study suggests a potential link between Fe and phosphorus cycling in these microorganisms.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Editorial Material
Multidisciplinary Sciences
Rosalind E. M. Rickaby
Summary: Analysis of plankton fossils has shown that the size diversity is linked to the circularity of Earth's orbits. This orbital variability may play a role in dictating the rhythm of evolution.
Article
Plant Sciences
Marc-Andre Cormier, Jean-Baptiste Berard, Gael Bougaran, Clive N. Trueman, Daniel J. Mayor, Richard S. Lampitt, Nicholas J. Kruger, Kevin J. Flynn, Rosalind E. M. Rickaby
Summary: The traditional separation between primary producers and consumers in the marine food web is being replaced by the paradigm of mixoplankton, which are planktonic protists capable of both heterotrophy and autotrophy. This shift in understanding has implications for primary production, biomass transfer, and CO2 sequestration in the deep ocean. However, there is currently no tool to quantify the relative contributions of autotrophy and heterotrophy in planktonic protists, hindering our understanding of carbon cycling in marine ecosystems. This study explores the use of hydrogen isotopic signature of lipid biomarkers as a novel tool to investigate the prevalence of mixotrophy in marine microorganisms.
Article
Environmental Sciences
Sam Fankhauser, Stephen M. Smith, Myles Allen, Kaya Axelsson, Thomas Hale, Cameron Hepburn, J. Michael Kendall, Radhika Khosla, Javier Lezaun, Eli Mitchell-Larson, Michael Obersteiner, Lavanya Rajamani, Rosalind Rickaby, Nathalie Seddon, Thom Wetzer
Summary: The concept of net-zero carbon emissions is rooted in physical climate science but is operationalized through social, political, and economic systems. Seven critical attributes have been identified for the successful implementation of net zero, emphasizing the urgency of emission reductions, coverage of all emission sources, cautious use of carbon dioxide removals, and alignment with broader sustainable development objectives.
NATURE CLIMATE CHANGE
(2022)
Article
Oceanography
Dharma Reyes-Macaya, Babette Hoogakker, Gema Martinez-Mendez, Pedro J. Llanillo, Patricia Grasse, Mahyar Mohtadi, Alan Mix, Melanie J. Leng, Ulrich Struck, Daniel C. McCorkle, Macarena Troncoso, Eugenia M. Gayo, Carina B. Lange, Laura Farias, Wilson Carhuapoma, Michelle Graco, Marcela Cornejo-D'Ottone, Ricardo De Pol Holz, Camila Fernandez, Diego Narvaez, Cristian A. Vargas, Francisco Garcia-Araya, Dierk Hebbeln
Summary: In this study, stable isotopes and other measurements were used to characterize the water masses in the Southeast Pacific. The results showed that stable isotopes of oxygen and deuterium can differentiate between different water masses, while dissolved inorganic carbon can provide further differentiation. The study also highlighted differences between the coastal and oceanic sections in terms of water mass characteristics.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Stergios D. Zarkogiannis, Shinya Iwasaki, James William Buchanan Rae, Matthew W. Schmidt, P. Graham Mortyn, George Kontakiotis, Jennifer E. Hertzberg, Rosalind E. M. Rickaby
Summary: By studying the shell weight of foraminifera, it was found that foraminifera shells near the equator weigh an average of 1/3 less than those from the middle latitudes, and deep dwelling species have heavier shells than surface-dwelling species, indicating a change in shell weight with depth. The results suggest that the ambient seawater carbonate chemistry does not account for the interspecies difference in shell mass.
FRONTIERS IN MARINE SCIENCE
(2022)
Review
Chemistry, Multidisciplinary
Christopher Batchelor-McAuley, Minjun Yang, Rosalind E. M. Rickaby, Richard G. Compton
Summary: This perspective discusses the confusion and contradictions in the description of the calcite dissolution reaction, highlighting the importance of mass-transport in experimental and oceanic sediment dissolution.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Environmental Sciences
Helge A. A. Winkelbauer, Babette A. A. Hoogakker, Rosie J. J. Chance, Catherine V. V. Davis, Christopher J. J. Anthony, Juliane Bischoff, Lucy J. J. Carpenter, Simon R. N. Chenery, Elliott M. M. Hamilton, Philip Holdship, Victoria L. L. Peck, Alex J. J. Poulton, Mark C. C. Stinchcombe, Karen F. F. Wishner
Summary: Planktic foraminifera test iodine to calcium ratios are a useful proxy method for assessing subsurface seawater oxygenation states. Lower I/Ca ratios have been observed in planktic foraminifera from locations with oxygen depleted subsurface waters. This is because only oxidized iodine species, such as iodate, are incorporated into foraminiferal calcite. However, planktic foraminifera from well oxygenated regions have significantly lower I/Ca ratios compared to similarly well-oxygenated core-top samples, suggesting post-mortem iodine uptake during settling or burial.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Ecology
El Mahdi Bendif, Ian Probert, Odysseas A. Archontikis, Jeremy R. Young, Luc Beaufort, Rosalind E. Rickaby, Dmitry Filatov
Summary: This study investigates the evolutionary relationships and ecological adaptations of G. huxleyi morphotypes across different environments. Results show that G. huxleyi is actually composed of at least three distinct species, and their divergence is related to glacial-cycle dynamics.
Review
Geochemistry & Geophysics
E. L. McClymont, S. L. Ho, H. L. Ford, I. Bailey, M. A. Berke, C. T. Bolton, S. De Schepper, G. R. Grant, J. Groeneveld, G. N. Inglis, C. Karas, M. O. Patterson, G. E. A. Swann, K. Thirumalai, S. M. White, M. Alonso-Garcia, P. Anand, B. A. A. Hoogakker, K. Littler, B. F. Petrick, B. Risebrobakken, J. T. Abell, A. J. Crocker, F. de Graaf, S. J. Feakins, J. C. Hargreaves, C. L. Jones, M. Markowska, A. S. Ratnayake, C. Stepanek, D. Tangunan
Summary: The Pliocene Epoch was a period of climate change characterized by smaller Northern Hemisphere ice sheets and long-term ice-sheet expansion. The intensification of Northern Hemisphere Glaciation caused asynchronous shifts in climate variability across regions and between climate proxies.
REVIEWS OF GEOPHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Wanyi Lu, Kassandra M. Costa, Delia W. Oppo
Summary: Reconstructing the strength and depth boundary of oxygen minimum zones (OMZs) in the glacial ocean provides insights into their response to climate changes. By analyzing oxygen reconstructions in Arabian Sea cores, we found that glacial OMZ had slightly higher oxygen concentrations in the shallow zone (< 1,000 m) and lower concentrations at greater depths (1,500-3,650 m) compared to the modern Arabian Sea. This suggests that the glacial OMZ in the Arabian Sea was better oxygenated but remained concentrated in the upper 1,000 m due to weaker upper ocean stratification and increased oxygen solubility.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Geosciences, Multidisciplinary
V. C. Khon, B. A. A. Hoogakker, B. Schneider, J. Segschneider, W. Park
Summary: This study suggests that the closure of the Central American Seaway (CAS) led to the development of the present-day tropical Pacific oxygen minimum zone (OMZ). The open CAS allowed for an enhanced eastward subsurface current, increasing the oxygen supply from the western tropical Pacific and resulting in a less developed OMZ in the eastern tropical Pacific.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Liao Chang, Babette A. A. Hoogakker, David Heslop, Xiang Zhao, Andrew P. P. Roberts, Patrick De Deckker, Pengfei Xue, Zhaowen Pei, Fan Zeng, Rong Huang, Baoqi Huang, Shishun Wang, Thomas A. A. Berndt, Melanie Leng, Jan-Berend W. Stuut, Richard J. J. Harrison
Summary: By studying a long magnetofossil record from the eastern Indian Ocean, we found coexisting phenomena of magnetic hardening, enlargement, and less oxidation of magnetofossils during glacials compared to interglacials over the past 900,000 years. Our multi-proxy records consistently suggest a recurring decrease in O2 levels in the glacial Indian Ocean, similar to observations in the Atlantic and Pacific during the last glaciation. This repeated oxygen decline strongly supports the hypothesis that increased carbon storage in the Indian Ocean during glacial periods played a significant role in atmospheric CO2 cycling and climate change over recent glacial/interglacial timescales.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Tommaso Paoloni, Babette Hoogakker, Alba Navarro Rodriguez, Ryan Pereira, Erin L. Mcclymont, Luigi Jovane, Clayton Magill
Summary: Foraminiferal shells are widely used in reconstructing past marine environments. This study aims to assess the molecular composition of FBOM and its influence on the proxy potential of FBOM delta 13C. The results show that polysaccharides and proteins dominate FBOM, with no detectable lipids. The use of FBOM delta 13C to reconstruct past atmospheric CO2 concentrations has an uncertainty of approximately +/- 21 ppm. The study suggests using FBOM delta 13C as a proxy for reconstructing POM delta 13C.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Plant Sciences
Qiong Zhang, Philip D. Charles, El Mahdi Bendif, Svenja S. Hester, Shabaz Mohammad, Rosalind E. M. Rickaby
Summary: This study investigates the stimulating and toxicity effect of chromium on a marine Chlorophyceae Osetreococcus tauri under different iron conditions. The presence of Cr(VI) significantly stimulates the growth and photosynthesis of the phytoplankton under Fe-replete conditions, while minor additions of Cr(VI) can partially rescue phytoplankton growth under Fe-limited conditions. Proteomic analysis indicates that the presence of Cr decreases the expression of phosphate-transporting and photosynthetic proteins, while increasing the expression of proteins related to carbon assimilation.
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)
