Review
Geochemistry & Geophysics
David M. Chew, Richard A. Spikings
Summary: The U-Pb apatite system is a powerful tool for studying thermal histories in the deeper crust, but it comes with various assumptions, challenges, and technical issues. The diverse trace-element chemistry of apatite can differentiate between different rock types, aiding in the accurate identification of reprecipitated domains.
Article
Geochemistry & Geophysics
Patrick A. Carr, Julien Mercadier, Matthieu Harlaux, Rolf L. Romer, Emeline Moreira, Helene Legros, Michel Cuney, Christian Marignac, Jean Cauzid, Lise Salsi, Andrei Lecomte, Olivier Rouer, Chantal Peiffert
Summary: Wolframite has been proposed as a U/Pb geochronometer for direct dating of W mineralisation events, but its isotopic analysis may be hampered by various factors. In situ U/Pb dating by LA-ICP-MS can provide more accurate results, as demonstrated in this study. The chemical variability and isotopic heterogeneity of wolframite in the French Massif Central highlight the need for pre-screening imaging methods before LA-ICP-MS analyses.
Article
Geochemistry & Geophysics
Makiko K. Haba, Joern-Frederik Wotzlaw
Summary: Eucrite meteorites are believed to originate from the upper crust of the asteroid Vesta, with zircons providing insight into the initial magmatism and thermal metamorphism that occurred around 4550-4555 million years ago on Vesta. By using advanced dating methods, researchers were able to distinguish zircons formed during different thermal events in the early stages of Vesta's crustal evolution, shedding light on the formation and history of the Vesta crust. The findings suggest that zircons in eucrites like Camel Donga were formed during early magmatism or global thermal metamorphism in the early stages of Vesta's crustal formation.
Review
Geosciences, Multidisciplinary
Tiantian Wang, Jahandar Ramezani, Chuan Yang, Jianghai Yang, Qiong Wu, Zhihui Zhang, Dawei Lv, Chengshan Wang
Summary: Sedimentary rocks are important repositories of Earth history, and the U-Pb radioisotopic system is a precise and accurate method for measuring absolute time. However, its application to the stratigraphic record relies on the presence of relatively pure volcanic ash deposits. Innovations in U-Pb ID-TIMS geochronology have improved precision and reproducibility, but have also revealed complexities in the U-Pb systematics of minerals.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geochemistry & Geophysics
Yu Zhang, Shuling Song, Pete Hollings, Dengfeng Li, Yongjun Shao, Huayong Chen, Lianjie Zhao, Sandra Kamo, Tingting Jin, Lingling Yuan, Qingquan Liu, Shaocong Chen
Summary: The timing of hydrothermal activity is crucial for predicting skarn mineralization, and vesuvianite may be a suitable mineral for dating skarn deposits. Through analyzing vesuvianite samples from nine Chinese skarn deposits, it was found that vesuvianite contains high concentrations of U and has a high Pb closure temperature, indicating its potential as a U-Pb geochronometer for skarn deposits.
Article
Geochemistry & Geophysics
Ruoxi Zhang, Kenny Nadeau, Eduardo Amilcar Gautier, Paola Alejandra Babay, Jose Luis Ramella, Marian Virgolici, Andreea Elena Serban, Viorel Fugaru, Yoshiki Kimura, Celia Venchiarutti, Stephan Richter, Yetunde Aregbe, Zsolt Varga, Maria Wallenius, Klaus Mayer, Hana Seo, Jung Youn Choi, Csaba Tobi, Mostafa Fayek, Ryan Sharpe, Kyle M. Samperton, Victoria D. Genetti, Rachel E. Lindvall, Jeremy D. Inglis, Joanna S. Denton, Andrew A. Reinhard, Barbara Francisco, Xiaolei Zhao, William Kieser, Juan He, Ying Gao, Juris Meija, Ali El-Jaby, Lu Yang, Zoltan Mester
Summary: This study presents data from thirteen laboratories worldwide for the successful certification of uranium isotope ratios in uranium ore concentrate (UOC) certified reference materials. The study found significant variation in uranium isotope ratios among the three candidate UOC CRMs, with uncertainties of the proposed certified values superior to available reference materials.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2022)
Article
Geochemistry & Geophysics
Janne Liebmann, Bryant Ware, Michael I. H. Hartnady, Christopher L. Kirkland, Nicholas E. Timms, Noreen J. Evans
Summary: Lead isotopes serve as a powerful tool in studying fundamental geological problems of continental crust formation and evolution. K-feldspar is commonly used for Pb isotope measurement and can capture the initial Pb isotope composition of its parent magma. This study presents data on a new Pb isotope reference material, Albany K-feldspar, as well as updated data for Shap K-feldspar. The results demonstrate the feasibility of Pb isotope determination using LA-MC-ICP-MS to access geological information preserved in small crystals, including mineral inclusions.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geochemistry & Geophysics
Olga V. Rezvukhina, Sergey G. Skublov, Dmitriy I. Rezvukhin, Andrey V. Korsakov
Summary: This study highlights the utility of rutile in reconstructing the metamorphic evolution of ultrahigh-pressure rocks containing diamond, showcasing its distinct textural positions and geochemical characteristics in a diamondiferous kyanite gneiss. The findings suggest a metapelitic origin of rutile and provide temperature estimates using Zr-in-rutile geothermometer. Dating results indicate a younger age for rutile compared to peak metamorphic assemblages, showcasing cooling rates and exhumation processes. The study demonstrates rutile as a valuable tool in understanding the metamorphic evolution of diamond-bearing rocks.
Article
Chemistry, Analytical
Urs Schaltegger, Maria Ovtcharova, Sean P. Gaynor, Blair Schoene, Jorn-Frederik Wotzlaw, Joshua F. H. L. Davies, Federico Farina, Nicolas David Greber, Dawid Szymanowski, Cyril Chelle-Michou
Summary: The study compared data from the geochronology laboratory of University of Geneva using ET100 and ET2000 solutions with results from Princeton University and ETH Zurich. It found that the choice of thermal ionization mass spectrometer model does not affect data precision and accuracy, and excess scatter in ET100 solution data can be reduced with careful tracer-sample equilibration. Additionally, natural zircon reference materials are not ideal for evaluating repeatability and reproducibility within and between laboratories due to their complexities.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2021)
Article
Geosciences, Multidisciplinary
Hector K. Garza, Elizabeth J. Catlos, Kevin R. Chamberlain, Stephanie E. Suarez, Michael E. Brookfield, Daniel F. Stockli, Richard A. Batchelor
Summary: Sedimentary rocks in Dob's Linn, Scotland, play a significant role in our understanding of the evolution of life during the Ordovician to Early Silurian periods. The study uses zircon dating to determine the ages of the rocks and faces challenges due to tectonic disturbances and correlation issues. The results provide precise dates and raise concerns about the suitability of Dob's Linn as a Global Boundary Stratotype Section and Point (GSSP) site.
GEOLOGICAL MAGAZINE
(2023)
Article
Geochemistry & Geophysics
Sean P. Gaynor, Melissa Ruiz, Urs Schaltegger
Summary: This study presents high-precision isotope dilution-thermal ionization mass spectrometry (ID-TIMS) U-Pb zircon data from the Carboniferous Punteglias granodiorite in Switzerland. The results show that the zircon crystals have a mixture of two different age components, and the crystallization age of the zircon is determined to be 335.479 +/- 0.041 Ma. Additionally, pretreating the zircon samples with physical and chemical abrasion reduces age dispersion and allows for a more accurate determination of the initial magmatic domains. The high analytical precision of this study is crucial for correctly interpreting complex age spectra.
Article
Chemistry, Analytical
Chao-Feng Li, Zhu -Yin Chu, Peng Peng
Summary: Thermal ionization mass spectrometry (TIMS) is widely used for lead isotopic ratio analysis due to its precision. A novel silicon nitride (beta-Si3N4) emitter on the tantalum filament is introduced, which provides good sensitivity for Pb isotopic ratio measurements and reduces the filament material cost by 70%. The method shows excellent internal precision and good external precision for various geological samples.
Article
Geochemistry & Geophysics
Chao Huang, Hao Wang, Jin-Hui Yang, Sandra L. Kamo, Jia-Run Tu, Zhen-Hui Hou, Le Zhang, Yue-Heng Yang, Lie-Wen Xie, Shi-Tou Wu, Lei Xu
Summary: This study presents a potential Archaean reference material for microbeam U-Pb dating, a natural rutile sourced from South Africa. Through various analysis methods, such as electron probe microanalysis, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), and isotope dilution-thermal ionisation mass spectrometry (ID-TIMS), precise and reproducible ages were obtained for the rutile sample.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geochemistry & Geophysics
Namik Aysal, Marcel Guillong, Tamara Bayanova, Mayuko Fukuyama, Nicole Leonard, Isak Yilmaz, Elif Varol, Fatma Sisman Tukel, Yusuf Kaan Kadioglu, Nurullah Hanilci, Fulya Uzun, Ersin Kaygisiz
Summary: Gem quality andradite-rich garnet from Turkey has been identified as a potential natural secondary reference material for U-Pb dating. U-Pb dating was performed using different methods in multiple labs, yielding consistent results. Another andradite from Turkey can also be used as a secondary reference material with detailed imaging. The assigned weighted mean age of the garnet (20.4 +/- 0.5 Ma, 2s) is proposed as a reference value for 2023. These findings suggest that the garnet will play an important role in the development of garnet geochronology.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geochemistry & Geophysics
Anera Kazlagic, Martin Rosner, Anna Cipriani, Daniel A. Frick, Johannes Glodny, Elis J. Hoffmann, John M. Hora, Johanna Irrgeher, Federico Lugli, Tomas Magna, Thomas C. Meisel, Anette Meixner, Antonio Possolo, Axel Pramann, Michael J. Pribil, Thomas Prohaska, Anika Retzmann, Olaf Rienitz, Daniel Rutherford, Gustavo M. Paula-Santos, Michael Tatzel, Sara Widhalm, Matthias Willbold, Tea Zuliani, Jochen Vogl
Summary: An interlaboratory comparison was conducted to determine Sr-87/Sr-86 isotope ratios in reference materials using the conventional method. Thirteen laboratories received six reference materials and a detailed technical protocol. Consensus values for the reference materials were obtained by applying a statistical model to the measurement results. The study demonstrates the importance of interlaboratory comparisons and provides reference materials for validation and quality control purposes.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Aleksandra Gaweda, Krzysztof Szopa, Jan Golonka, David Chew, Leonid Stepanyuk, Volodymir Belskyy, Anna Waskowska, Laurynas Siliauskas, Foteini Drakou
Summary: This study focused on two nappe units in the Ukrainian Marmarosh Massif, analyzing their structure and age through petrological and zircon dating methods, revealing possible geological processes. The origins and evolutionary history of metavolcanic rocks and phyllite host rocks were investigated, providing important clues for interpreting geological events.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2022)
Article
Geochemistry & Geophysics
Syed Ali Turab, Kurt Stuewe, Finlay M. Stuart, Nathan Cogne, David M. Chew, Joerg Robl
Summary: The formation of the Great Escarpment in southwestern Saudi Arabia was a result of the rifting of the Red Sea. A combination of low-temperature geochronology and geomorphic analysis of the region suggests that the escarpment may have a younger exhumation history than previously thought.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geography, Physical
Valerio Olivetti, Maria Laura Balestrieri, David Chew, Luca Zurli, Massimiliano Zattin, Donato Pace, Foteini Drakou, Gianluca Cornamusini, Matteo Perotti
Summary: Based on the study of glaciomarine sediments in DSDP Site 270 in the central Ross Sea, we determined the extent of ice sheet evolution in the late Oligocene to early Miocene, revealing a transition from local to regional-scale ice sheets. Our data also identified the source of sediment transported by ice streams from different areas in the Transantarctic Mountains and the West Antarctic Rift System. These new findings provide robust geological constraints for modeling ice sheet volumes and ice drainage patterns in the late Oligocene-early Miocene.
GLOBAL AND PLANETARY CHANGE
(2023)
Article
Geology
Matthias Konrad-Schmolke, Ralf Halama, David Chew, Celine Heuze, Jan De Hoog, Hana Ditterova
Summary: Variations of rare earth element concentrations in metamorphic garnet provide important information about geodynamic and geochemical processes in the deeper Earth. By utilizing high-resolution trace element and mu-Raman mapping, combined with thermodynamic-geochemical-diffusion models, it is possible to distinguish and quantify the thermodynamic equilibrium and kinetic contributions of REE uptake in garnet. The presence of heavy rare earth element zoning, as well as the concentric patterns of minor recurring fluctuations in the REE concentrations, suggest recurring changes in rock permeabilities due to pulsed fluid fluxes during metamorphism.
JOURNAL OF METAMORPHIC GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Paul Slezak, Murray W. Hitzman, David van Acken, Eoin Dunlevy, David Chew, Foteini Drakou, Mark Holdstock
Summary: The Limerick Igneous Suite in County Limerick, SW Ireland, consists of two distinct basaltic igneous units: Knockroe and Knockseefin. These units exhibit various types of volcanic rocks. U.Pb dating of apatite indicates a primary crystallization age of approximately 350 Ma for the Knockroe units. The geological characteristics and isotopic values suggest that the Limerick Igneous Suite shares similarities with ocean island basalts and likely originated from low degrees of partial melting associated with the amalgamation of Laurussia and Gondwana.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2023)
Article
Geochemistry & Geophysics
Teal R. R. Riley, Ian L. L. Millar, Andrew Carter, Michael J. J. Flowerdew, Alex Burton-Johnson, Joaquin Bastias, Craig D. D. Storey, Paula Castillo, David Chew, Martin J. J. Whitehouse
Summary: The LeMay Group accretionary complex in Alexander Island consists of deformed turbidites and thrust slices of ocean floor basalts. The age and provenance of this complex are uncertain, ranging from Carboniferous to Cretaceous. The accretion history is poorly established, but our geochronology and geochemistry analysis suggests its deposition, provenance, and accretion occurred during the Permian to mid-Triassic, mid-Cretaceous, and Early Jurassic respectively.
Review
Geosciences, Multidisciplinary
Joaquin Bastias, David Chew, Camila Villanueva, Teal Riley, Joseline Manfroi, Cristine Trevisan, Marcelo Leppe, Paula Castillo, Fernando Poblete, Dieter Tetzner, Gregory Giuliani, Bastian Lopez, Hong Chen, Guang-Gao Zheng, Yue Zhao, Liang Gao, Anna Rauch, Ricardo Jana
Summary: In the South Shetland Islands, geological studies have greatly contributed to the understanding of its geological evolution. However, little research has been done on the correlation of geological units throughout the archipelago. This study provides a lithostratigraphical correlation and a new geological map for the South Shetland Islands, revealing three main stages of geological and environmental evolution.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geochemistry & Geophysics
Oluwaseun Edward, Andre Navin Paul, Hugo Bucher, Christian Verard, Thierry Adatte, Jeroen E. Sonke, Urs Schaltegger, Torsten Vennemann
Summary: This study investigates the timing and source of volcanic fluxes around the Permian-Triassic boundary mass extinction in South China. The results indicate that subduction-related volcanic arc magmatism in the Tethys region contributed to the causes of the mass extinction, and that mercury anomalies near the boundary are not a reliable stratigraphic marker for the extinction event.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geology
Dengfeng Li, Jinzhou Peng, David Chew, Yongjia Liang, Pete Hollings, Yu Fu, Yanhui Dong, Xiaoming Sun
Summary: Deep-sea sediments rich in rare earth elements and yttrium (REY) are potential mineral resources associated with fish debris burial. The lack of age constraints has been a limiting factor in understanding the nature of REY enrichment. However, this study reports bioapatite U-Pb ages from cores in the Pacific Ocean, providing insights into the timing and mechanism of REY mineralization. The results suggest that the Miocene REY accumulation event in the western Pacific Ocean was influenced by high P2O5 and MnO2 contents correlated with oxic bottom water.
Article
Geosciences, Multidisciplinary
Zengjie Zhang, J. Stephen Daly, Yuntao Tian, Chao Lei, Xilin Sun, Eszter Badenszki, Yonghui Qin, Jie Hu
Summary: Using Pb isotopes in detrital K-feldspar, we address the debated initiation time of the Pearl River. The Eocene and Early Oligocene sandstones in the northern South China Sea were supplied by proximal rivers draining the Cathaysia Block, while the Late Oligocene and Miocene sandstones mainly originated from the western Pearl tributaries. Detrital zircon data from the Beibuwan Basin suggest that the western tributaries flowed into this basin before being captured by the paleo-Pearl River, indicating a progressive headward erosion and late Oligocene integration of the Pearl River.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
P. Vermeesch, A. G. Lipp, D. Hatzenbuehler, L. Caracciolo, D. Chew
Summary: Varietal studies of sedimentary provenance involve analyzing the properties of minerals or mineral groups. Multidimensional Scaling (MDS) can be used to analyze this type of data and treat it equally with other provenance proxies. The paper introduces three methods to measure the dissimilarity between samples in order to apply MDS to varietal data.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geosciences, Multidisciplinary
Michael J. Flowerdew, Edward J. Fleming, David M. Chew, Andrew C. Morton, Dirk Frei, Aukje Benedictus, Jenny Omma, Teal. R. Riley, Eszter Badenszki, Martin J. Whitehouse
Summary: Through a sediment provenance study, it is found that the topography generated by Eocene Eurekan deformation plays a significant role as a sediment source for sandstones deposited on the western Barents Shelf margin. The study records a provenance change across the Paleocene-Eocene boundary in wellbore BH 10-2008, indicating a shift in source area from the exposed Barents Shelf terrain to the emerging Eurekan mountains during the Eocene.
Article
Geochemistry & Geophysics
Andre N. Paul, Joseph A. Stewart, Samuele Agostini, Linda A. Kirstein, Jan C. M. De Hoog, Ivan P. Savov, Kristina Walowski, James W. B. Rae, Tim Elliott
Summary: This study presents a low-blank sample preparation procedure for boron isotope measurement in silicate rocks using MC-ICP-MS. The method effectively addresses the challenges of volatilisation during silicate dissolution and contamination during chemical purification. The results demonstrate the accuracy and consistency of the method and reveal the heterogeneity in boron isotopes in the upper mantle.
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Tao Deng, Xiumian Hu, David Chew, Jan Schoenig, Anlin Ma, Wendong Liang, Foteini Drakou
Summary: This study provides evidence that the present-day tectonic architecture and drainage systems in eastern China were established in the Early Jurassic, with the exhumation of the Dabie orogen marking the development of the watershed between Northern and Southern China.
Article
Geosciences, Multidisciplinary
Er-Kun Xue, Wei Wang, David Chew, Manoj K. Pandit, Xin Deng, Yang Tian, Xi-Run Tong, Jun-Hong Zhao
Summary: The study reveals the presence of water-fluxed melting during the Wuyi-Yunkai Orogeny in South China. These water-fluxed melting quartzo-feldspathic migmatites formed during the early Paleozoic and were melted through reactions involving water-saturated quartz, feldspar, biotite, and K-feldspar. The findings highlight the significance of water-fluxed anatexis in the differentiation of the continental crust during orogenesis.
Article
Geochemistry & Geophysics
Xinze Lu, Geoffrey J. Gilleaudeau, Brian Kendall
Summary: The Late Ordovician mass extinction is the first major extinction event in the Phanerozoic, but the reasons for the decline in global biodiversity before the extinction are not well understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
Article
Geochemistry & Geophysics
Junyao Kang, Daniel D. Gregory, Benjamin Gill, Shiqiang Huang, Changxin Lai, Zhaoshan Chang, Huan Cui, Ivan Belousov, Shuhai Xiao
Summary: Sedimentary pyrite is an important geological archive, but it can be altered by diagenetic and hydrothermal processes. This study successfully trained machine learning algorithms to distinguish pyrite origins using trace element data. The approach was validated and applied to identify the origins of pyrite in two sedimentary successions in South China.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
