Article
Geochemistry & Geophysics
Eloise Bessiere, Stephane Scaillet, Romain Augier, Laurent Jolivet, Jose Miguel Azanon, Guillermo Booth-Rea, Adrien Romagny, Florian Duval
Summary: This article addresses the issue of interpreting geochronologic data in the Betic-Rif orogen. Through 40Ar/39Ar dating of white mica samples, it reveals a HP event in the Early Eocene (around 38 million years ago) and a regional stage of exhumation at 20 million years ago. This study provides compelling evidence for overcoming the problem of extensive late-orogenic overprinting.
Article
Geosciences, Multidisciplinary
Farzaneh Shakerardakani, Franz Neubauer, Manfred Bernroider, Fritz Finger, Christoph Hauzenberger, Johann Genser, Michael Waitzinger, Behzad Monfaredi
Summary: This study reports the metamorphic conditions and evolution of the Dorud-Azna metamorphic units in the central part of the Sanandaj-Sirjan zone (SSZ), Iran. The results reveal the polyphase metamorphism in two different basement units and provide new insights into the tectonic history of the SSZ. The findings suggest the influence of rift and plate collision processes, reflecting various stages of a Wilson cycle.
GEOSCIENCE FRONTIERS
(2022)
Article
Geochemistry & Geophysics
Alexandre Peillod, Jaroslaw Majka, Uwe Ring, Kirsten Druppel, Clifford Patten, Andreas Karlsson, Adam Wlodek, Elof Tehler
Summary: Determining the tectonic evolution and thermal structure of a tectonic unit that experiences a subduction-related pressure temperature (P-T) loop is challenging. The study reveals different P-T evolution paths in the Cycladic Blueschist Unit on Naxos, with the bottom recording higher peak high-pressure than the top, defining a thickness of about 15 km. The bottom half of the CBU section was thrust onto the radiogenic Cycladic basement around 30 Ma.
Article
Geochemistry & Geophysics
Valentin Laurent, Stephane Scaillet, Laurent Jolivet, Romain Augier, Vincent Roche
Summary: The behavior of the phengite 40Ar/39Ar system was studied in Sifnos and Syros Islands, showing a decrease in phengite ages with progressive strain localization during exhumation. Grain-scale variations in Ar retention properties and thermal-kinetic processes play a significant role in controlling the phengite ages in the rock samples.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Timmons M. Erickson, Christopher L. Kirkland, Fred Jourdan, Martin Schmieder, Michael I. H. Hartnady, Morgan A. Cox, Nicholas E. Timms
Summary: By combining multiple geochronologic techniques, this study successfully determined the impact age of the Haughton Dome to be approximately 31.8 Ma, resolving previous discrepancies and interpretations of post-impact stratigraphy within the crater fill.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Alexiane Favier, Chrystele Verati, Jean-Marc Lardeaux, Philippe Munch, Christophe Renac, Michel Corsini, Francois Orange
Summary: The study investigates the potential of 40Ar39Ar systematics in secondary K-bearing minerals formed from hydrothermally altered volcanic pyroxenes in a fossil geothermal system in the Saintes archipelago. It presents the first example of dating hydrothermal muscovite crystallization in altered rhyodacites, providing new insights into high temperature fluid circulation. The model of muscovite substitution by illite during cooling helps interpret the perturbation of K-Ar and Ar-Ar ages by illitization.
Article
Geochemistry & Geophysics
Alissa J. Kotowski, Miguel Cisneros, Whitney M. Behr, Daniel F. Stockli, Konstantinos Soukis, Jaime D. Barnes, Daniel Ortega-Arroyo
Summary: Exhumed high-pressure/low-temperature metamorphic rocks on Syros Island provide insights into the subduction interface dynamics. The island consists of three coherent tectonic slices that underwent subduction, underplating, and syn-subduction return flow at progressively younger times. The metamorphic and deformation history (P-T-D) and timing of subduction and exhumation are revealed through lineations, ductile fold axis orientations, and amphibole zonations. The revised tectonic framework suggests distributed, ductile, and coaxial return flow in an Eocene-Oligocene subduction channel, accommodating a significant amount of exhumation.
Article
Geochemistry & Geophysics
Sanna Holm-Alwmark, Fred Jourdan, Ludovic Ferriere, Carl Alwmark, Christian Koeberl
Summary: This study focuses on the Puchezh-Katunki impact structure in Russia, accurately dating its formation to 195.9 +/- 1.0 Ma using 40Ar/39Ar data. The research challenges previous temporal correlations between the impact event and multiple extinction events, emphasizes the importance of careful sample preparation and methodology in overcoming 40Ar issues, and highlights the need for caution when suggesting connections between specific impact events and extinction events.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Review
Geosciences, Multidisciplinary
Yang Wu, Xiu-Juan Bai, He-Sheng Shi, Li-Yan He, Hua-Ning Qiu
Summary: This paper provides a review of dating methods relying on the K-Ar and Rb-Sr isotopic decay systems applied in sedimentary rocks. It discusses the sample preparation and analytical techniques associated with these methods and summarizes their applications in various sedimentary settings. The paper also highlights the use of Rb-Sr and 40Ar/39Ar dating in determining depositional ages and trapped ancient atmospheric argon components in chert.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geography, Physical
Alan L. Deino, Clifford Heil, John King, Lindsay J. McHenry, Ian G. Stanistreet, Harald Stollhofen, Jackson K. Njau, Joshua Mwankunda, Kathy D. Schick, Nicholas Toth
Summary: The Olduvai Gorge Coring Project in Tanzania drilled cores at three sites in the Olduvai Basin, developing a chronostratigraphic framework. Through dating, paleomagnetic stratigraphy, and tephrochemical correlation, they obtained realistic age estimates. The age models revealed varying sedimentation rates in the basin's history and provided new estimates for the basal contacts of upper stratigraphic units in Olduvai Gorge.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
Augustin Dekoninck, Gilles Ruffet, Julien Baptiste, Robert Wyns, Simon Philippo, Yishen Zhang, Olivier Namur
Summary: This study discusses the hydrothermal formation of romanechite in the Romane`che Mn deposit and the significance of its age by combining ore petrogenesis and 40Ar/39Ar ages. The study confirms the feasibility of romanechite 40Ar/39Ar dating and identifies a period of at least c. 7.6 My of discontinuous hydrothermal activity in the Massif Central.
Article
Geography, Physical
Sander L. Hilgen, Eduard Pop, Shinatria Adhityatama, Tom A. Veldkamp, Harold W. K. Berghuis, Indra Sutisna, Dida Yurnaldi, Guillaume Dupont-Nivet, Tony Reimann, Norbert Nowaczyk, Klaudia F. Kuiper, Wout Krijgsman, Hubert B. Vonhof, Dian Rahayu Ekowati, Gerrit Alink, Ni Luh Gde Dyah Mega Hafsari, Olafianto Drespriputra, Alexander Verpoorte, Remco Bos, Truman Simanjuntak, Bagyo Prasetyo, Josephine C. A. Joordens
Summary: This study aims to establish an accurate age control for the fossils found at the Trinil site in Java, Indonesia. By applying various dating methods and documenting new stratigraphic sections, the researchers identified two distinct fossil-rich channel fills with ages ranging from 830-773 ka to 450 +/- 110 ka. The presence of fossils from different time periods challenges the assumption of a homogeneous biostratigraphic unit at the Trinil site.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geochemistry & Geophysics
P. W. Ball, G. G. Roberts, D. F. Mark, D. N. Barfod, N. J. White, B. H. Lodhia, M. M. Nahdi, S. Garni
Summary: Harrat Rahat is the largest volcanic field in Saudi Arabia and has been active from around 10 Ma to the present day. Recent eruptions at Harrat Rahat have been extensively studied, but the evolution of its oldest lava flows, known as the Shawahit Basalt, is poorly understood. In this study, we collected and analyzed samples from Harrat Rahat, focusing on the Shawahit unit. We found that the volcanic activity at Harrat Rahat was initiated by a mantle plume beneath a thinned lithosphere, and the changes in geochemistry can be attributed to a decrease in melt productivity and contamination.
Article
Geosciences, Multidisciplinary
R. Spikings, A. Paul, C. Vallejo, P. Reyes
Summary: The gabbros and ultramafic rocks of the Huargualla Gabbro unit in Ecuador were derived from asthenospheric sources with minor crustal contamination and formed part of the Central Iapetus Magmatic Province. These rocks represent the only igneous record of Iapetus rifting north of the Huancabamba deflection in South America. The age and composition of the Huargualla Gabbro unit is consistent with the reconstruction by Tegner et al. (2019), suggesting juxtaposition of Baltica and northwestern Gondwana within Panotia.
Article
Chemistry, Physical
Artur Kuligiewicz, Michal Skiba, Marek Szczerba, Chris M. Hall, Dorota Bakowska
Summary: This study developed a new interpretative method for K-Ar and 40Ar/39Ar dating, capable of handling a three-component mixture. The mineral composition of clay gouges from the Tatra Mountains in Poland was also reported.
CLAYS AND CLAY MINERALS
(2022)
Article
Geosciences, Multidisciplinary
Allen J. Schaen, Brian R. Jicha, Kip Hodges, Pieter Vermeesch, Mark E. Stelten, Cameron M. Mercer, David Phillips, Tiffany A. Rivera, Fred Jourdan, Erin L. Matchan, Sidney R. Hemming, Leah E. Morgan, Simon P. Kelley, William S. Cassata, Matt T. Heizler, Paulo M. Vasconcelos, Jeff A. Benowitz, Anthony A. P. Koppers, Darren F. Mark, Elizabeth M. Niespolo, Courtney J. Sprain, Willis E. Hames, Klaudia F. Kuiper, Brent D. Turrin, Paul R. Renne, Jake Ross, Sebastien Nomade, Herve Guillou, Laura E. Webb, Barbara A. Cohen, Andrew T. Calvert, Nancy Joyce, Morgan Ganerod, Jan Wijbrans, Osamu Ishizuka, Huaiyu He, Adan Ramirez, Jorg A. Pfander, Margarita Lopez-Martinez, Huaning Qiu, Brad S. Singer
Summary: The 40Ar/39Ar dating method is versatile and can provide precise age constraints for a wide range of materials, but age dispersion must be considered. The interpretation of dates depends on the geological problem being addressed and the assumptions associated with each data set, highlighting the need for collateral information to better constrain interpretation.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2021)
Article
Geochemistry & Geophysics
Xiaolong Zhou, Klaudia Kuiper, Jan Wijbrans, Pieter Vroon
Summary: The mechanism controlling volcanic eruption frequency is not well understood. By combining accurate geochronology with numerical models, this study aims to improve our understanding of volcanic eruption frequency in a long-lived felsic magmatic system. Two numerical models are used to analyze the Milos volcanic field and the results indicate that the time intervals between magma pulses and magma supply rates are the key parameters controlling eruption frequency.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Eleonora Balkanska, Stoyan Georgiev, Alexandre Kounov, Milorad Antic, Takahiro Tagami, Shigeru Sueoka, Jan Wijbrans, Irena Peytcheva
Summary: The study uncovered the Alpine thermal and tectonic evolution of the central parts of the Sredna Gora Zone in Bulgaria, revealing multiple thermal and cooling episodes related to various tectonic and magmatic events. Through dating of different samples, the study identified the timing and temperatures of different thermal events, shedding light on the complex evolutionary history of the area.
GEOLOGICA CARPATHICA
(2022)
Article
Geochemistry & Geophysics
Bertram Uunk, Fraukje Brouwer, Manuel De Paz-Alvarez, Kirsten van Zuilen, Rosanne Huybens, Reinier van 't Veer, Jan Wijbrans
Summary: This study constrains the timing and conditions of subducted, exhumed, and exposed high pressure metamorphic rocks on the Cyclades islands in Greece, showing a progressive subduction and exhumation resulting in imbrication of a former continental margin. Different mechanisms may trigger consistent exhumation for mechanically strong rocks and weakly coupled supracrustal rocks.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Limin Zhao, Yilong Li, Chao Rong, Fulin Li, Hua Xiang, Jianping Zheng, Fraukje M. Brouwer
Summary: The tectonic mechanism responsible for the Neoproterozoic magma generation at the northern margin of the Yangtze craton was studied systematically, and it was suggested that the South Qinling orogenic belt formed due to bidirectional subduction of the South Qinling Ocean. The formation process of the rhyolites was also described in detail.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
Yilong Li, Hua Xiang, Jianping Zheng, Huaning Qiu, Xiujuan Bai, Fraukje M. Brouwer
Summary: The Qilian orogen, which marks the northern boundary of the Proto-Tethys Ocean, has been studied in this paper to better understand the closure of the ocean. The metamorphic P-T-t path of amphibolites from the Central Qilian block is investigated, revealing the peak metamorphic conditions and subsequent cooling stages. The findings suggest that the Central Qilian block was affected by both southward and northward subduction, resulting in paired metamorphic belts.
JOURNAL OF PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Kristof Porkolab, Liviu Matenco, Jasper Hupkes, Ernst Willingshofer, Jan Wijbrans, Hugo van Schrojenstein Lantman, Douwe J. J. van Hinsbergen
Summary: The high-pressure metamorphic Nevado-Filabride Complex (NFC) in the Betics mountain range of southeastern Spain plays a crucial role in understanding the geodynamics of the Western Mediterranean. By conducting a structural study and single grain fusion 40Ar/39Ar dating, researchers resolved debates related to tectonic units, emplacement of (ultra)mafic rocks, and timing of burial metamorphism. The presence of an ophiolitic melange led to a new tectonic hypothesis, which explains the subduction and exhumation processes and provides a solution for the age constraints of high pressure-low temperature metamorphism in the NFC.
Article
Multidisciplinary Sciences
Rongguo Hu, Baocheng Pang, Xiujuan Bai, Fraukje M. Brouwer, Lingan Bai, Xijun Liu, Yuanqiang Li, Jianqi Xu, Huaning Qiu
Summary: This study demonstrates the feasibility and potential of using progressive crushing 40Ar/39Ar dating to determine the mineralization age and decipher the fluid origins of Carlin-type gold deposits.
SCIENTIFIC REPORTS
(2022)
Article
Geochemistry & Geophysics
Leah E. E. Morgan, Brett Davidheiser-Kroll, Klaudia F. F. Kuiper, Darren F. F. Mark, Noah M. M. McLean, Jan R. R. Wijbrans
Summary: The accuracy and traceability of geochronometers are crucial to questions asked by Earth scientists. This study focuses on the 40Ar/39Ar geochronometer and its co-irradiation with reference materials. The authors used various calibration methods to determine the ages of monitor minerals and found that the current results do not meet the desired accuracy, but the extensive methodology development presented in this study can help improve future measurements.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geochemistry & Geophysics
L. B. Streicher, W. van Westrenen, J. M. Hanchar, F. M. Brouwer
Summary: Several methods have been proposed to trace geological processes using rare earth element (REE) concentrations in zircon. Precise determination of REE partition coefficients (D) in zircon is challenging, especially for light rare earth elements. However, modeling with a prediction function based on the crystal lattice strain model can overcome this difficulty.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Limin Zhao, Yilong Li, Hua Xiang, Jianping Zheng, Wenjiao Xiao, Xi Chen, Hai Jiang, Yachao Xie, Fraukje M. Brouwer
Summary: This paper presents a systematic study of the Xiong'erling pluton and adjacent appinite dikes in the North Qinling orogenic belt. The petrology, mineral chemistry, whole-rock geochemistry, and geochronology reveal the properties of continental lithospheric mantle and crust-mantle geodynamics. The rocks in this area belong to the shoshonitic series and were emplaced in an intraplate extensional environment.
JOURNAL OF PETROLOGY
(2023)
Article
Geochemistry & Geophysics
B. Petri, J. R. Wijbrans, G. Mohn, G. Manatschal, M. Beltrando
Summary: The thermal evolution of the Austroalpine Campo and Grosina units, which were part of the necking zone of the Adriatic rifted margin, were studied. The two units exhibited different thermal histories, with the Grosina unit undergoing a slow cooling process during the Permo-Triassic period and the Campo unit experiencing a rapid cooling process during the Jurassic rifting. These findings provide insights into the tectonic evolution and thermal subsidence of the region.
Article
Geosciences, Multidisciplinary
Igor K. Nikogosian, Antoine J. J. Bracco Gartner, Paul R. D. Mason, Douwe J. J. van Hinsbergen, Klaudia F. Kuiper, Uwe Kirscher, Sergei Matveev, Araik Grigoryan, Edmond Grigoryan, Arsen Israyelyan, Manfred J. van Bergen, Janne M. Koornneef, Jan R. Wijbrans, Gareth R. Davies, Khachatur Meliksetian
Summary: This study presents new geochronological, palaeomagnetic, and geochemical constraints to understand the geodynamic evolution of the South Armenian Block (SAB) and its Gondwanan origin. It reveals the timing of rifting and provides insights into the geological history of the SAB since the Permian.
Article
Environmental Sciences
Yanpu Zhao, Jan R. Wijbrans, Hua Wang, Pieter Z. Vroon, Jianghao Ma, Yanqiong Zhao
Summary: Hydrochemistry and strontium isotope data were analyzed to study the variations in chemical weathering and CO2 consumption fluxes in the Xi River Drainage system. The main ions were Ca2+, Mg2+, and HCO3-, indicating a drainage system on carbonate-dominated bedrock. The weathering rates of silicate and carbonate increased downstream, while the carbonate weathering rates peaked in the middle reaches. Chemical weathering variations were mainly controlled by lithology, vegetation, and climate factors. The Xi River Basin is a CO2 sink with a net consumption of CO2 flux.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2023)
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)