Article
Geosciences, Multidisciplinary
Yair Rosenthal, Samantha Bova, Xiaoli Zhou
Summary: Although there is uncertainty about the accuracy of different calibrations of foraminiferal magnesium/calcium (Mg/Ca) measurements for reconstructing sea surface temperature (SST), applying five calibrations to six published records of Globigerinoides ruber reveals that the reconstructed temperature anomalies are consistent within the uncertainties, despite differences in temperature sensitivity among the equations.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Laura L. Haynes, Baerbel Honisch, Kate Holland, Stephen Eggins, Yair Rosenthal
Summary: Foraminiferal Mg/Ca is an important parameter for reconstructing past sea-surface temperature, but recent studies suggest that seawater pH, DIC, and Mg/Ca-sw composition can affect its accuracy. Laboratory culture experiments with living foraminifera reveal that pH effects are reduced or absent at certain Mg/Ca-sw values, and that T. sacculifer is the most insensitive species to variable DIC and pH, making it ideal for SST reconstructions.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Geochemistry & Geophysics
Turner Richmond, Jeremy Cole, Gabriella Dangler, Michael Daniele, Thomas Marchitto, Edgar Lobaton
Summary: The presented work describes Forabot, an open-source system for physically manipulating and isolating foraminifera with minimal human interaction. Researchers can build their own Forabot using low-cost, off-the-shelf components. The system is capable of processing a large number of foraminifera samples, with potential for further optimization in processing speed. A proof-of-concept classifier based on artificial intelligence achieves a high classification accuracy.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Chen Zhu, Tianyu Chen, Liang Zhao
Summary: The study explores the potential role of vaterite as a precursor phase affecting Mg incorporation into foraminifera calcite shells, demonstrating that Mg partitioning is mainly controlled by strain energy. The two-step partition model developed based on experimental results can reproduce foraminiferal calcite Mg/Ca temperature dependencies, suggesting that biological pumping of Mg outside calcifying fluid might not be a precondition for foraminifera shell mineralization.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Ecology
Maximiliano Rodriguez, Christelle Not
Summary: This study developed temperature calibrations for two shallow marine ostracods, showing that they can be used as paleothermometers for paleoreconstructions. The Mg/Ca ratios of S. impressa and N. delicata ostracods were found to significantly correlate with temperature, with S. impressa being preferred for reconstructions. This method provides valuable information on oceanic circulation at a regional scale.
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
Geochemistry & Geophysics
Cassandre R. Stirpe, Katherine A. Allen, Elisabeth L. Sikes, Xiaoli Zhou, Yair Rosenthal, Alicia M. Cruz-Uribe, Hanna L. Brooks
Summary: The Mg/Ca ratio of Uvigerina peregrina is commonly used to reconstruct bottom water paleotemperatures, but anomalies at some sites suggest the influence of non-temperature factors. Further research is needed to fully understand these effects and validate paleotemperature reconstructions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Paleontology
Jing Lyu, Tanja J. Kouwenhoven, Roberta Calieri, Lucas J. Lourens
Summary: The study of foraminiferal data from Crete reveals the impact of the restriction phase starting at 7.17 Ma on the Mediterranean marine life, with a decrease in benthic diversity and an increase in species tolerant of hypersalinity. The data also suggests a shift towards hypoxic conditions and decreasing oxygen content of bottom waters after 7.17 Ma, possibly indicating an increase in water salinity affecting both bottom and surface waters simultaneously.
MARINE MICROPALEONTOLOGY
(2022)
Article
Geochemistry & Geophysics
Surajit Mondal, Pallavi Anand, Ramananda Chakrabarti
Summary: In this study, a comprehensive assessment of the temperature sensitivity of delta Ca-44/40 in foraminifera was conducted using multiple isotopic and elemental ratios. A novel paleotemperature equation for foraminifera was proposed, combining delta Ca-44/40 and Mg/Ca, which can mitigate the uncertainty associated with individual proxy measurements and allow cross-validation.
Article
Geography, Physical
Raquel Bryant, R. Mark Leckie, Timothy J. Bralower, Matthew M. Jones, Bradley B. Sageman
Summary: Oceanic Anoxic Event 2 (OAE2) occurred in the latest Cenomanian and affected the global carbon cycle. Research in the southwestern edge of the seaway during OAE2 in Carthage, New Mexico, USA reveals distinct environmental changes and high productivity conditions in the marine ecosystem.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
N. Levy, A. Torfstein, R. Schiebel, N. Chernihovsky, K. P. Jochum, U. Weis, B. Stoll, G. H. Haug
Summary: It has been found that hydrohaline oligotrophic seas can accommodate marine calcareous Planktic Foraminifera (PF) shells with higher Mg/Ca and different temperature to Mg/Ca relationships compared to open marine environments. This study investigates the factors influencing the Mg uptake in hypersaline regions and presents a framework for incorporating elevated Mg/Ca into global Mg/Ca-T calibrations for two PF species, Globigerinoides ruber albus and Turborotalita clarkei, in the Gulf of Aqaba, northern Red Sea.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Multidisciplinary Sciences
Brittany N. Hupp, D. Clay Kelly, John W. Williams
Summary: The study uses the carbon isotope anomaly marking the PETM to investigate the response of tropical planktic foraminifers during the PETM, revealing that nearly half of foraminifer shells in the record are reworked contaminants. Corrected assemblages show a significant decrease in diversity at the open-ocean site during the PETM, likely caused by heat stress and ocean acidification. These findings suggest that the adaptability of these calcifiers may be strained by the rapid ocean warming and acidification projected for the coming centuries.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geography, Physical
Sudhira R. Bhadra, Rajeev Saraswat
Summary: The effect of mid-Pleistocene transition (MPT) on the Indian monsoon has been studied using a 1.45 million-year record of planktic foraminifera assemblages. The results show a significant reorganization of the monsoon system and a strengthening of the Indian summer monsoon (ISM) after the onset of the MPT.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Ecology
Delphine Dissard, Gert Jan Reichart, Christophe Menkes, Morgan Mangeas, Stephan Frickenhaus, Jelle Bijma
Summary: Studies have shown that foraminiferal Mg/Ca can accurately reconstruct surface water temperature, and when combined with equations, delta O-18 can also be reconstructed. However, salinity reconstruction based on locally calibrated equations has lower precision.
Article
Geochemistry & Geophysics
Xiaoli Zhou, Yair Rosenthal, Laura Haynes, Weimin Si, David Evans, Kuo-Fang Huang, Barbel Honisch, Jonathan Erez
Summary: The study demonstrates the potential of Na/Ca in planktic foraminifera as a new proxy for reconstructing Cenozoic variations in seawater Na/Ca. Culture experiments validate the approach and show that foraminiferal Na/Ca responds to changes in seawater calcium concentration. The down core planktic foraminiferal records consistently show lower Na/Ca during the mid-Miocene than during the late Pleistocene, primarily reflecting changes in seawater calcium concentration.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Biodiversity Conservation
L. E. Kearns, S. M. Bohaty, K. M. Edgar, T. H. G. Ezard
Summary: This study investigates the response of Paleogene planktonic foraminifera to climate change using fossil records. The results show that communities featuring smaller genera are more resilient to climatic fluctuations compared to those featuring only larger genera. These findings are important for understanding how communities respond to climate change.
Article
Geochemistry & Geophysics
James Kershaw, Joseph A. Stewart, Ivo Strawson, Maria Luiza de Carvalho Ferreira, Laura F. Robinson, Katharine R. Hendry, Ana Samperiz, Andrea Burke, James W. B. Rae, Rusty D. Day, Peter J. Etnoyer, Branwen Williams, Vreni Haussermann
Summary: Based on the study of modern Stylasteridae corals, it is found that [Ba]SW and sample mineralogy are the main factors influencing coral Ba/Ca ratios, while seawater temperature has a weak influence. Paired Sr/Ca measurements suggest that the variability in scleractinian Ba/Ca may be related to varying degrees of Rayleigh fractionation during calcification. Stylasteridae corals have the potential to be an important new archive for paleoceanographic studies.
Article
Multidisciplinary Sciences
Robin van der Ploeg, Margot J. Cramwinckel, Ilja J. Kocken, Thomas J. Leutert, Steven M. Bohaty, Chris D. Fokkema, Pincelli M. Hull, A. Nele Meckler, Jack J. Middelburg, Inigo A. Muller, Donald E. Penman, Francien Peterse, Gert-Jan Reichart, Philip F. Sexton, Maximilian Vahlenkamp, David De Vleeschouwer, Paul A. Wilson, Martin Ziegler, Appy Sluijs
Summary: The Middle Eocene Climatic Optimum (MECO) experienced a transient warming of 3 degrees Celsius, leading to increased salinity in the North Atlantic subtropical gyre and potentially a poleward expansion of its northern boundary.
Article
Geosciences, Multidisciplinary
David De Vleeschouwer, Donald E. E. Penman, Simon D'haenens, Fei Wu, Thomas Westerhold, Maximilian Vahlenkamp, Carlotta Cappelli, Claudia Agnini, Wendy E. C. Kordesch, Daniel J. J. King, Robin van der Ploeg, Heiko Palike, Sandra Kirtland Turner, Paul Wilson, Richard D. Norris, James C. C. Zachos, Steven M. M. Bohaty, Pincelli M. M. Hull
Summary: Cyclostratigraphy and astrochronology are important techniques in geologic timekeeping. The accuracy of astronomical calculations is crucial, but there are limitations due to solar system chaos. High-resolution paleoclimate records now allow for a reversal of the traditional approach, and the sediment records from Newfoundland Ridge are well-suited for this purpose.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Geochemistry & Geophysics
Qian Liu, Laura F. Robinson, Erica Hendy, Maria G. Prokopenko, Timothy D. J. Knowles, Tao Li, Ana Samperiz
Summary: Deep-sea bamboo corals have been used as archives for reconstructing past ocean changes, but the interpretation of geochemical signals recorded in their organic nodes, particularly regarding water depth, remains uncertain. Through isotopic analysis of bamboo corals collected from the central and eastern tropical Atlantic, contrasting results were found between the two regions. The carbon source for bamboo coral organic nodes may not always reside in the mixed layer, especially in oligotrophic regions, which has implications for age model development.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geosciences, Multidisciplinary
Kirsty M. M. Edgar, Lewis Haller, Daniel D. D. Cashmore, Emma M. M. Dunne, Richard J. J. Butler
Summary: Dinosaur tracks are an important tool for understanding the ecology and distribution of dinosaurs. The UK has a rich history of dinosaur track discoveries, and this new dataset shows a close correlation between the distribution of sediments and the preservation of dinosaur tracks. The track record reveals similar patterns to the body fossil record, but also provides unique insights into dinosaur communities and shows a trend towards higher numbers of tracks over time.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2023)
Article
Geology
Kirsty M. Edgar, Luke E. Meade, Harry T. Jones, Lewis Haller, Sam Scriven, Christopher Reedman, Richard J. Butler
Summary: Spyway Quarry in Dorset is the largest easily accessible UK dinosaur tracksite, with over 100 tracks made by sauropod dinosaurs. The trackway surface has undergone changes over time due to natural processes, resulting in the reduction of track prominence. Visitor data indicates an annual visitation of approximately 10,000 people, with potential improvements suggested for visitor directions and information. Our study emphasizes the importance of using 3D imaging techniques for documenting and preserving site legacies.
PROCEEDINGS OF THE GEOLOGISTS ASSOCIATION
(2023)
Article
Environmental Sciences
Wenhao Wang, Heather Goring-Harford, Korinna Kunde, E. Malcolm S. Woodward, Maeve C. Lohan, Douglas P. Connelly, Rachael H. James
Summary: Chromium isotopic composition in ancient marine sediments can be used to infer changes in past seawater oxygenation or biological productivity. The relative contribution of external sources and internal cycling on the distribution of dissolved chromium in the oceans is still debated. In this study, water column profiles were obtained for dissolved chromium concentrations and chromium isotopes in the sub-tropical North Atlantic. The results suggest that benthic inputs and the formation of colloid aggregates of Fe-(oxyhydr)oxides play important roles in shaping the distribution of chromium.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Ecology
Anieke Brombacher, Paul A. Wilson, Ian Bailey, Thomas H. G. Ezard
Summary: This study investigates the trait covariation patterns of two planktonic foraminifera species in different environments and populations. The results show a stable spatial signal but inconsistent temporal changes, suggesting that individual populations cannot be used to predict the response of others.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Geosciences, Multidisciplinary
V. E. Taylor, T. Westerhold, S. M. Bohaty, J. Backman, T. Dunkley Jones, K. M. Edgar, K. E. Egan, M. Lyle, H. Paelike, U. Roehl, J. Zachos, P. A. Wilson
Summary: New sediment records indicate a significant shift in the calcite compensation depth (CCD) during the Eocene-Oligocene Transition, suggesting a strong connection between calcium carbonate cycling and Antarctic glaciation. This event perturbed the global carbon cycle and triggered rapid changes in global seawater chemistry, leading to transient deep ocean carbonate burial fluxes.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Environmental Sciences
Swaantje Brzelinski, Andre Bornemann, Diederik Liebrand, Tim E. van Peer, Paul A. Wilson, Oliver Friedrich
Summary: This study examines the climate variability during the late Oligocene, a period characterized by high CO2 levels and warmer-than-present conditions, using well-preserved benthic foraminifera. The results show that the late Oligocene experienced glacial-interglacial cycles with ice-volume changes similar to those in the late Pliocene and early Pleistocene. The findings also suggest that the Antarctic ice-sheet extended beyond the coastline during glacials, indicating its vulnerability to melting under late Oligocene climate conditions.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Geochemistry & Geophysics
Surajit Mondal, Pallavi Anand, Ramananda Chakrabarti
Summary: In this study, a comprehensive assessment of the temperature sensitivity of delta Ca-44/40 in foraminifera was conducted using multiple isotopic and elemental ratios. A novel paleotemperature equation for foraminifera was proposed, combining delta Ca-44/40 and Mg/Ca, which can mitigate the uncertainty associated with individual proxy measurements and allow cross-validation.
Article
Geochemistry & Geophysics
Rebecca L. Parker, Gavin L. Foster, Marcus Gutjahr, Paul A. Wilson, Stephen P. Obrochta, Nathalie Fagel, Matthew J. Cooper, Agnes Michalik, James A. Milton, Ian Bailey
Summary: The deglaciation during Termination 5 (T5) led to an interglacial period known as Marine Isotope Stage 11 (MIS11), and understanding the retreat of the Laurentide Ice Sheet (LIS) during this time is crucial for assessing sea-level rise. A new study provides high-resolution records of Pb isotopes and rare earth elements, revealing the timing and process of LIS retreat during T5 and highlighting the importance of North American ice loss in sea-level rise. Comparison with the deglaciation history of the southern Greenland Ice Sheet during T5, T2, and T1 also emphasizes the need for specific regional models in glacio-isostatic adjustment modeling.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Multidisciplinary Sciences
Marcelo A. De Lira A. Mota, Tom Dunkley Jones, Nursufiah Sulaiman, Kirsty M. M. Edgar, Tatsuhiko Yamaguchi, Melanie J. J. Leng, Markus Adloff, Sarah E. E. Greene, Richard Norris, Bridget Warren, Grace Duffy, Jennifer Farrant, Masafumi Murayama, Jonathan Hall, James Bendle
Summary: 34 million years ago, the growth of the Antarctic Ice Sheet led to a fall in sea level, causing the shift of nutrients and carbon from continental margins to the ocean, which slowed global cooling and ice sheet expansion. The expansion of the East Antarctic Ice Sheet during the Eocene-Oligocene Transition (EOT) is a significant event in Earth's climate history. By analyzing proxies from a shallow shelf location and using an Earth System model, researchers found that the earliest stage of EOT experienced a marked regression and an elevated flux of continental-derived organic matter, which acted as a transient negative feedback to climate cooling through delivering a pulse of organic carbon to the oceans.
NATURE COMMUNICATIONS
(2023)