Article
Geochemistry & Geophysics
Gabriel West, Andreas Nilsson, Alexis Geels, Martin Jakobsson, Matthias Moros, Francesco Muschitiello, Christof Pearce, Ian Snowball, Matt O'Regan
Summary: This study investigates the behavior of the geomagnetic field in polar regions during the late Holocene period. By analyzing well-dated sediment cores from the Chukchi Sea, Arctic Ocean, the authors provide valuable insights into the changes in the geomagnetic field in the Arctic over the past few thousand years.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geography, Physical
Yan Zheng, Hongbo Zheng, Qianying Guo, Qing Yang, Zhujun Hu, Xinya Yao, Xinying Zhou, Keliang Zhao, Xiaoqiang Li, Chenglong Deng
Summary: The Hemudu site is an important archaeological site in East China, providing valuable insights into how Neolithic people managed coastal farmland. By conducting high-resolution paleomagnetic chronology work on core samples from Hemudu, researchers were able to discuss early Holocene paleoclimate changes in Southern China. The study identified magnetic minerals, established a relative paleointensity, and refined the age-depth model for the site, demonstrating the impact of global paleoclimate variations on the sedimentary sequence. The research also highlighted the development of pile dwellings and cultivation of wild rice in the early Holocene, pointing to a local paleoenvironmental change influenced by transgression events.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
Torsten Haberzettl, Thomas Kasper, Joseph S. Stoner, Jean Jacques Rahobisoa, Gerhard Daut
Summary: The paleomagnetic records derived from maar lakes in Madagascar provide valuable insights into the paleomagnetic secular variations in (southern) Africa, showing similarities with global geomagnetic field reconstructions and other geological records. These new data help distinguish reliable paleomagnetic data from potentially problematic ones, improving the understanding of paleomagnetic changes in the region.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geography, Physical
Steve Lund, Ellen Platzman, Chris Scholz
Summary: A paleomagnetic study was conducted on three piston cores from Lake Turkana to recover a Holocene paleomagnetic secular variation (PSV) record and correlate it with other PSV records from the East Africa Rift Valley. Magnetic measurements were made on the cores, and the resulting records could be correlated. The sediment ages were estimated through PSV age estimation and radiocarbon dating, and showed good consistency. The Lake Turkana PSV record is the highest resolution directional record of PSV ever recovered from Africa.
Article
Geochemistry & Geophysics
Steve Lund, Gary Acton, Brad Clement, Makoto Okada, Lloyd Keigwin
Summary: This paper summarizes the paleomagnetic secular variation (PSV) and excursions recorded from sediment measurements in the western North Atlantic Ocean at ODP Sites 1060, 1061, 1062, and 1063. It identifies various features and dates the records using different methods. The records from Sites 1062 and 1063 are found to be the most consistent and high-resolution.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2022)
Article
Geochemistry & Geophysics
Annemarieke Beguin, Adriano Pimentel, Lennart de Groot
Summary: By analyzing and integrating new paleomagnetic data from Pico Island in the Azores Archipelago, this study successfully constructed a curve of the direction and intensity changes of the Earth's magnetic field over the past two thousand years. The research revealed a period of low inclination between AD 900 and 1560, with minimum values of 32 degrees.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geography, Physical
Steve Lund, Ellen Platzman, Thomas C. Johnson
Summary: The study conducted paleomagnetic research on Holocene sediments from Lake Victoria to develop a high-resolution record of paleomagnetic secular variation. The results indicate that the PSV records are limited to the uppermost 5 meters of the cores due to significant magnetic mineral dissolution. By correlating PSV and rock magnetic/environmental measurements, the study provides a well-dated record of Holocene PSV for Africa, which can be compared with PSV records from Lake Malawi.
Article
Geochemistry & Geophysics
Steve Lund, Gary Acton, Brad Clement, Makoto Okada, Lloyd Keigwin
Summary: This study summarizes the pattern of paleomagnetic secular variation (PSV) and excursions within MIS 6-7 in the western North Atlantic Ocean, revealing two excursions by analyzing PSV records and dating methods. The research indicates a continuing regional dynamo process responsible for these excursions over a period of more than 35,000 years.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2021)
Article
Geochemistry & Geophysics
Marcel Bliedtner, Torsten Haberzettl, Norbert Nowaczyk, Enkhtuya Bazarradnaa, Roland Zech, Paul Strobel
Summary: Despite the inconsistency between paleomagnetic secular variations (PSV) and radiocarbon (C-14)-based lacustrine sediment chronologies at Khar Nuur in the Mongolian Altai Mountains, the inclination pattern at the site resembles regional and global geomagnetic field models with a constant offset of 730 +/- 90 years. The offset is not caused by reservoir effects or modern factors, but rather by the constant lock-in depth of 26 +/- 2 cm below the sediment-water interface at Khar Nuur. The good consistency in inclination further highlights the reliability of global geomagnetic field models in under-studied areas.
Article
Geochemistry & Geophysics
Brendan T. Reilly, Joseph S. Stoner, Saedis Olafsdottir, Anne Jennings, Robert Hatfield, Greta Bjork Kristjansdottir, Aslaug Geirsdottir
Summary: We investigated the amplitude and frequency of geomagnetic change in the Northern North Atlantic region over the past 15 thousand years. Using high-resolution sediment cores, we validated prior results and provided stronger geochronological constraints on the paleomagnetic secular variation signal. Our study also revealed greater variability and higher amplitudes on centennial timescales, which is important for understanding the geodynamo.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Oceanography
Marta Miatta, Paul Vr Snelgrove
Summary: The study investigated the impact of organic matter remineralization and nutrient regeneration in deep-sea sedimentary habitats in the Laurentian Channel Marine Protected Area off Newfoundland, Canada. It found that biodiversity and environmental factors were the primary drivers of variation in benthic nutrient fluxes, with macrofauna explaining up to 41% of the variation, highlighting the importance of ecosystem functioning. The presence of sea pens was associated with enhanced ammonium efflux rates, but did not appear to influence other fluxes, indicating the need for further studies to understand benthic processes and their implications for conservation strategies.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2021)
Article
Multidisciplinary Sciences
Prantik Mandal
Summary: Understanding the dominant crustal accretion model in Archean cratons is essential for understanding early crust formation processes. This study models Moho depths and crustal Vp/Vs ratios in the Eastern Indian Shield to test plume and subduction models. The results show a correlation between crustal age and composition, indicating different crustal accretion processes in different regions.
SCIENTIFIC REPORTS
(2022)
Article
Oceanography
Steve Lund, Makoto Okada, Emily Mortazavi
Summary: This study develops composite full-vector paleomagnetic secular variation (PSV) records from IODP Ex. 323 Sites U1339, U1343, U1344, and U1345 in the Bering Sea. These PSV records cover the last 71 ka (Marine Isotope Stages (MIS) 1-4) and provide important insights into the magnetic field behavior at high latitudes.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Geochemistry & Geophysics
Steve P. Lund, Martha Schwartz, Lloyd Keigwin
Summary: New paleomagnetic records recovered from deep-sea sediment cores of the Bahama Outer Ridge reveal the occurrence of the Blake Event around 119-126,000 years BP within Marine Isotope Stage 5. The Blake Event is characterized by a local magnetic field reversal and our detailed analysis confirms deviations from long-term averages on various timescales.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2021)
Article
Geology
Ruth M. Corkill, Gillian M. Turner
Summary: The paleomagnetic records of three lake sediment cores in northern New Zealand have been merged to produce a new Holocene geomagnetic secular variation record. These records were correlated using tephra and magnetic susceptibility variations, showing well-defined swings in magnetic direction at different time periods. The regional nature of geomagnetic secular variation is indicated by its agreement with records from Mavora Lakes, 1000 km further south.
NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS
(2022)
Article
Ecology
Biljana Narancic, Emilie Saulnier-Talbot, Guillaume St-Onge, Reinhard Pienitz
Summary: The Arctic has experienced significant warming in recent decades. The evolution of Arctic climate during the Holocene needs further clarification. Lake water pH is influenced by hydrological processes dependent on climate variations.
Article
Geography, Physical
Nathan Stevenard, Jean-Carlos Montero-Serrano, Frederique Eynaud, Guillaume St-Onge, Sebastien Zaragosi, Luke Copland
Summary: The study investigated the glacial sediment discharge process and the impact of the North Water Polynya on sediment dynamics at Cape Norton Shaw Inlet in northwestern Baffin Bay. It revealed that Early Holocene sediment dynamics were mainly influenced by sea ice, iceberg rafting, and meltwater discharges, while Canadian Shield sediment inputs dominated later. The depth record of sedimentation indicates the response of glaciers to climate change over time.
Article
Environmental Sciences
Obinna P. Nzekwe, Francois Lapointe, Pierre Francus, Guillaume St-Onge, Patrick Lajeunesse, David Fortin, Jean-Philippe Jenny, Arnaud De Coninck, Edouard G. H. Philippe, Thibault Labarre
Summary: This study presents a high-resolution climate reconstruction sensitive to the North Atlantic Oscillation (NAO) using a new varve record from Lake Walker. It found that negative winter NAO resulted in thicker snow cover, increased river discharges, and a stronger clastic component in the varves.
JOURNAL OF PALEOLIMNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Alexandre Normandeau, Patrick Lajeunesse, Jean-Francois Ghienne, Pierre Dietrich
Summary: High-resolution imagery of modern active turbidite systems reveals detailed information about the morphology and behavior of turbidity currents. This study presents a dataset obtained from an autonomous underwater vehicle with 30 cm-resolution, which provides new insights into the erosional and depositional processes associated with turbidity currents. The imagery shows the impact of basal layer erosion, the formation of plunge pools, and the influence of hydraulic jump troughs on flow paths. Additionally, small-scale scours suggest that weak flows follow local relief and explain the variability of flow indicators observed in outcrops.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geography, Physical
Meril Merindol, Guillaume St-Onge, Nabil Sultan, Patrick Lajeunesse, Sebastien Garziglia
Summary: The Charlevoix-Kamouraska/Bas-Saint-Laurent (CKBSL) seismic zone in eastern Canada has a seismic hazard similar to that of the active Pacific zone. A major earthquake in 1663 triggered numerous submarine landslides in the St. Lawrence Estuary, indicating a relationship between earthquakes and submarine slope failures. Analysis of sediment cores and dating techniques revealed four periods of synchronous submarine landslides corresponding to strong historical earthquakes, with the event in 1663 being the most significant in the region in the past two millennia.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Geology
Alexandre Normandeau, Jordan B. R. Eamer, Pascal Bernatchez, David Didier, Patrick Lajeunesse, Audrey Limoges, Jean-Carlos Montero-Serrano
Summary: This study describes the distribution of sediment density flows on wave-influenced deltas by examining four deltaic sedimentary systems at different stages of their evolution on the continental inner shelf of eastern Canada. The results suggest that sediment density flows occur in various types of environments, including large deltas, wave-influenced to wave-dominated deltas, and advanced stages of wave-dominated deltas. Different types of sediment density flows were identified, characterized by debris flows, surge-type turbidity currents, and hyperpycnal flows.
Article
Geography, Physical
Pierre-Olivier Couette, Patrick Lajeunesse, Jean-Francois Ghienne, Boris Dorschel, Catalina Gebhardt, Dierk Hebbeln, Etienne Brouard
Summary: Multibeam bathymetric and seismostratigraphic data provide insights into the glacial landforms and depositional assemblages in the Clyde fjord-cross-shelf trough system. The maximal extent of the Laurentide Ice Sheet margin during the Last Glacial Maximum is identified, along with the patterns and controls on its subsequent retreat. The sediment cores and radiocarbon ages reveal the depositional processes and the episodic style of deglaciation in the early Holocene.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geography, Physical
Kai-Frederik Lenz, Andrea Catalina Gebhardt, Patrick Lajeunesse, Arne Lohrberg, Felix Gross, Sebastian Krastel
Summary: Lakes in glaciated regions can provide valuable paleoclimate records. Lake Manicouagan, formed in the basin of an impact crater in eastern Quebec, is a key area for studying long-term environmental change. Seismic data reveals a deep valley filled with sediments and suggests that the sediments could serve as a paleoclimate archive. The shape of the valley indicates complex erosional processes, and the deposition of the sedimentary sequence is likely a result of both subglacial and proglacial sedimentation.
JOURNAL OF QUATERNARY SCIENCE
(2023)
Article
Geography, Physical
Pierre-Arnaud Desiage, Guillaume St-Onge, Mathieu J. J. Duchesne, Jean-Carlos Montero-Serrano, Miguel J. J. Haller
Summary: This study provides a detailed description of the upper sedimentary succession in the Gulf of San Jorge, based on high-resolution seismic profiles and sediment cores. It confirms the existence of a paleo-fluvial network buried by estuarine deposits during marine transgression. The analysis suggests a rapid sea-level rise consistent with Meltwater Pulse 1A, highlighting the significant impact of sea-level rise on sedimentation in the gulf.
JOURNAL OF QUATERNARY SCIENCE
(2023)
Article
Geography, Physical
Pierre-Olivier Couette, Jean-Francois Ghienne, Patrick Lajeunesse, Jerome van der Woerd
Summary: The Laurentide Ice Sheet (LIS) was the largest ice sheet in the Northern Hemisphere during the last glacial cycle. Its demise had significant effects on global climate and sea-level changes. Understanding the relationship between ice sheets and climatic events is crucial for predicting future ice sheet melting and its impact on sea-level changes.
JOURNAL OF QUATERNARY SCIENCE
(2023)
Article
Geography, Physical
Maria-Emilia Rodriguez-Cuicas, Jean-Carlos Montero-Serrano, Guillaume St-Onge, Alexandre Normandeau
Summary: Two sedimentary sequences from Coronation Fjord in Canada were studied to understand the impact of climate variability on sediment transfer from the Penny Ice Cap over the past 600 years. The results showed that glacial meltwater discharge caused frequent rapidly deposited layers in ice-proximal areas, while large sediment-laden water releases from adjacent fjords resulted in rapidly deposited layers in ice-distal areas. The analysis also indicated that colder conditions during the Little Ice Age promoted glacier growth and led to turbid meltwater plumes and iceberg calving.
JOURNAL OF QUATERNARY SCIENCE
(2023)
Article
Geography, Physical
Quentin Duboc, Patrick Lajeunesse, Guillaume St-Onge, Matthias Moros, Kerstin Perner
Summary: Constraining the final retreat of the Laurentide Ice Sheet is important for understanding the impacts of glacial retreat on landscapes, sedimentary processes, oceanography, and climate variations in Eastern North America. This paper investigates the deglacial sedimentary sequences from Nachvak and Saglek Fjords in Northern Labrador, revealing thick deglacial sequences and important mass-movement deposits. The results suggest that earthquakes, sediment export, and Labrador Sea waters influenced the deglacial and postglacial sedimentary dynamics of the fjords.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Flavienne Bruyant, Remi Amiraux, Marie-Pier Amyot, Philippe Archambault, Lise Artigue, Lucas Barbedo de Freitas, Guislain Becu, Simon Belanger, Pascaline Bourgain, Annick Bricaud, Etienne Brouard, Camille Brunet, Tonya Burgers, Danielle Caleb, Katrine Chalut, Herve Claustre, Veronique Cornet-Barthaux, Pierre Coupel, Marine Cusa, Fanny Cusset, Laeticia Dadaglio, Marty Davelaar, Gabriele Deslongchamps, Celine Dimier, Julie Dinasquet, Dany Dumont, Brent Else, Igor Eulaers, Joannie Ferland, Gabrielle Filteau, Marie-Helene Forget, Jerome Fort, Louis Fortier, Marti Gali, Morgane Gallinari, Svend-Erik Garbus, Nicole Garcia, Catherine Gerikas Ribeiro, Colline Gombault, Priscilla Gourvil, Clemence Goyens, Cindy Grant, Pierre-Luc Grondin, Pascal Guillot, Sandrine Hillion, Rachel Hussherr, Fabien Joux, Hannah Joy-Warren, Gabriel Joyal, David Kieber, Augustin Lafond, Jose Lagunas, Patrick Lajeunesse, Catherine Lalande, Jade Lariviere, Florence Le Gall, Karine Leblanc, Mathieu Leblanc, Justine Legras, Keith Levesque, Kate-M. Lewis, Edouard Leymarie, Aude Leynaert, Thomas Linkowski, Martine Lizotte, Adriana Lopes dos Santos, Claudie Marec, Dominique Marie, Guillaume Masse, Philippe Massicotte, Atsushi Matsuoka, Lisa A. Miller, Sharif Mirshak, Nathalie Morata, Brivaela Moriceau, Philippe-Israel Morin, Simon Morisset, Anders Mosbech, Alfonso Mucci, Gabrielle Nadai, Christian Nozais, Ingrid Obernosterer, Thimote Paire, Christos Panagiotopoulos, Marie Parenteau, Noemie Pelletier, Marc Picheral, Bernard Queguiner, Patrick Raimbault, Josephine Ras, Eric Rehm, Llucia Ribot Lacosta, Jean-Francois Rontani, Blanche Saint-Beat, Julie Sansoulet, Noe Sardet, Catherine Schmechtig, Antoine Sciandra, Richard Sempere, Caroline Sevigny, Jordan Toullec, Margot Tragin, Jean-Eric Tremblay, Annie-Pier Trottier, Daniel Vaulot, Anda Vladoiu, Lei Xue, Gustavo Yunda-Guarin, Marcel Babin
Summary: The Green Edge project investigates the phytoplankton spring bloom in the Arctic Ocean and its response to environmental changes. It is a multidisciplinary collaborative project involving researchers and technicians from seven countries. The project utilizes various sampling strategies and measurement techniques to understand the changes in Arctic Ocean biology and their impacts on the future.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Environmental Sciences
Pierre-Olivier Couette, Patrick Lajeunesse, Jean-Francois Ghienne, Boris Dorschel, Catalina Gebhardt, Dierk Hebbeln, Etienne Brouard
Summary: This study reveals a large moraine system extending along the continental slope off Baffin Island, indicating that a 500-meter thick ice shelf covered northern Baffin Bay during the Last Glacial Maximum. This ice shelf had a profound impact on the stability of the Laurentide, Innuitian, and Greenland ice sheets.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
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)
