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
Geology
Birger Rasmussen, Jian-Wei Zi, Janet R. Muhling
Summary: The study on in situ Th-Pb geochronology of phosphate minerals reveals different stages of fluid flow activities during the Paleoproterozoic and Phanerozoic in the Archean craton, showing the association of major continental breakup events in the Mesozoic with phosphate growth periods. Investigating carbonaceous shale from the 2.76 Ga Mount Roe Basalt in the Pilbara Craton, rhabdophane is proposed as a potential indicator for U-Th-Pb geochronology, allowing dating of low-temperature fluid flow and hydrous alteration events.
Article
Geology
Alexandre Cugerone, Francoise Roger, Benedicte Cenki, Emilien Oliot, Jean-Louis Paquette
Summary: Research in the Boss`ost dome of the Pyrenean Axial Zone has shown that mineralization formation is controlled by Variscan tectonics and associated with a major Variscan remobilization event. The poly-magmatic and metamorphic events in the Pyrenean Axial Zone have unclear relationships with the mineralization.
ORE GEOLOGY REVIEWS
(2021)
Article
Geochemistry & Geophysics
Bartosz Budzyn, Jiri Slama, Fernando Corfu, James Crowley, Mark Schmitz, Michael L. Williams, Michael J. Jercinovic, Gabriela A. Kozub-Budzyn, Patrik Konecny, Grzegorz Rzepa, Adam Wlodek
Summary: A single megacryst of Neoproterozoic monazite (TS-Mnz) was studied using various analytical techniques, revealing both unaltered and altered domains, with U-Pb and Th-Pb dating results obtained by different methods. The TS-Mnz showed relatively reproducible U-Pb, Th-Pb, and U-Th-total Pb dates, making it a potential new age reference material for in-situ U-Th-Pb microanalysis.
Article
Chemistry, Analytical
Guo-Qi Liu, Kui-Dong Zhao, Thomas Ulrich, Wei Chen, Di Zhang, Qian Li, He-Dong Zhao, Rong-Qing Zhang, Fei Xia
Summary: The Isoclock software is developed for robust U-Pb dating of accessory minerals using LA-ICP-MS. It focuses on deducting common Pb from reference materials and provides a new common Pb correction method. The software allows the deduction of common Pb in 206Pb, 207Pb, and 208Pb, enabling U/Pb and Th/Pb age calculations. Isoclock has a user-friendly interface and is written in Python, making it versatile and accessible for researchers.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2023)
Article
Geochemistry & Geophysics
C. J. Barnes, J. Majka, P. Jeanneret, G. Ziemniak, E. Kooijman, K. Kosminska, M. Kielman-Schmitt, D. A. Schneider
Summary: Geochronology of Th-rich minerals benefits from utilizing three isotopic systems for accurate data assessment. The Pb-208/Th-232 system is particularly advantageous in cases with initial Pb components, as it is the least sensitive to initial Pb effects. Laser ablation inductively coupled mass spectrometry has been used to successfully date different generations of monazite and interpret their formation processes.
Article
Geochemistry & Geophysics
Camila Pineda, Axel K. Schmitt, Diego Morata
Summary: Zircon is a widely studied mineral for geochronology, and its Th/U ratios play a critical role in isochron dating and radiometric age correction. However, the processes causing Th/U variations in zircon crystals are not fully understood. This study presents new data on the Th/U ratios and ages of zircon from a volcanic eruption in central Chile, providing important insights into the factors influencing Th/U ratios in zircon.
Letter
Geochemistry & Geophysics
Bartosz Budzyn, Richard Wirt, Jirf Slama, Gabriela A. Kozu-Budzyn, Anja Schreiber
Summary: The distribution of Th and U in the crystal of pegmatitic xenotime-(Y) has been studied using transmission electron microscopy (TEM), revealing the presence of unaltered domains with high Th and U, as well as altered domains with Th and U depletion and inclusions of (Th, U)-silicate and uraninite. The TEM examination of a FIB-foil prepared from the unaltered xenotime showed a network of dislocations, containing enriched U, Th, and Si material, surrounded by radiation-damaged xenotime. The migration and segregation of U and Th into dislocation cores at the atomic scale highlights the importance of nanoscale investigations in understanding age data and applying xenotime geochronology.
Article
Geosciences, Multidisciplinary
Zhongwu Lan
Summary: Authigenic xenotime and monazite are common in siliciclastic sedimentary rocks and can be used to determine the depositional age. Their small size and complex chemical compositions require advanced imaging and dating techniques. Integrated petrographic and geochemical studies can help distinguish their different sources.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geochemistry & Geophysics
Bartosz Budzyn, Richard Wirth, Jiri Slama, Gabriela A. Kozub-Budzyn, Grzegorz Rzepa, Anja Schreiber
Summary: Through studying monazite grains from the Gory Sowie Block in Poland, it was found that surface metamorphism and secondary monazite replacement can affect age records, while monazite from felsic granulites is more stable. The Pb-208/Th-232 chronometer shows the most accurate results and is recommended for monazite geochronology.
Article
Chemistry, Analytical
Lydia A. Rush, Andrew M. Duffin, Carmen S. Menoni
Summary: This study investigates the potential of extreme ultraviolet laser ablation and ionization time-of-flight mass spectrometry (EUV TOF) for reducing matrix effects in geological analyses. The results show that EUV TOF can accurately measure the Pb-206/U-238 and Th-232/U-238 isotope ratios in certain geological materials, but there are biases in uranium-bearing minerals. Overall, EUV laser ablation and ionization is a promising technique for directly measuring isotopic content in select geological materials.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2022)
Article
Geochemistry & Geophysics
Wei Zhang, Wei Terry Chen, Daniel Harlov, Jian-Feng Gao
Summary: This study investigates the effects of hydrothermal alteration on the U-Th-Pb dating of bastnasite in a Mo-REE deposit in Central China. It finds that non-radiogenic Pb is incorporated into altered bastnasite in the form of nanoscale galena inclusions, significantly affecting the U-Pb dating but having limited effects on the Th-Pb dating. The results highlight the need to treat the U-Pb and Th-Pb systems separately when dating bastnasite from secondary hydrothermal events.
AMERICAN MINERALOGIST
(2023)
Article
Geosciences, Multidisciplinary
Zhen M. G. Li, Yi-Chao Chen, Qian W. L. Zhang, Jia-Hui Liu, Chun-Ming Wu
Summary: This study provides new insights on the tectonic affinity of the Kang-Dian region in the Neoproterozoic from a metamorphic perspective. The long duration of the metamorphic event in the Kang-Dian region, over 100 Ma, suggests a long-lived orogenic process rather than a super-plume scenario. The metamorphic P-T conditions indicate an extensive compressional environment with prevailing deviatoric stress, possibly a subduction zone.
PRECAMBRIAN RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
C. Hours, L. Claparede, N. Reynier-Tronche, I Viallard, R. Podor, N. Dacheux
Summary: Heterogeneous U1-xThxO2 polished pellets were prepared through sintering of hydroxide precursors, and their distribution and dissolution behavior were studied. The dissolution rates of the materials were found to increase with the introduction of HNO2 catalytic species and decrease with the increasing incorporation rate of Th-enriched heterogeneities. Microscopic study showed preferential dissolution zones in the matrix and the refractory nature of the heterogeneities. The collected residues of dissolution exhibited slight dissolution progress with the formation of dissolution pits and attacks on grain boundaries. This study provides valuable insights into the dissolution behavior of heterogeneous U1-xThxO2 mixed oxides.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Geochemistry & Geophysics
Amy C. Moser, Bradley R. Hacker, George E. Gehrels, Gareth G. E. Seward, Andrew R. C. Kylander-Clark, Joshua M. Garber
Summary: This study investigates the dating of deformation and fluid-driven recrystallization using titanite U-Pb dates, trace elements, zoning, and microstructures in a calc-silicate gneiss along the Coast shear zone. The results show that deformation microstructures enhance fluid-mediated recrystallization, but also decouple U-Pb dates from trace-element concentrations. This study demonstrates the complexity of fluid and deformation processes within and among individual grains.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Geosciences, Multidisciplinary
Carlos Alberto Spier, Cesar Fonseca Ferreira Filho, Nathan Daczko
Summary: This study investigates the age and tectonic history of the chromite-mineralised Bacuri Complex, revealing it as one of the oldest and best-preserved layered intrusions known. It also provides evidence that continental crust in the Amazonian Craton was established in the Paleoarchean and has been reworked since at least the Mesoarchean.
Article
Geosciences, Multidisciplinary
D. Silva, N. R. Daczko, S. Piazolo, T. Raimondo
Summary: This study examines the formation of glimmerite bands in a high-strain zone in central Australia and reveals the role of melt migration and fluid-rock interaction in the replacement process. The study analyzes the microstructures and chemical compositions to understand the modification of quartzite to glimmerite and proposes the occurrence of coupled dissolution-precipitation reactions during melt flux. The findings contribute to our understanding of the relationship between rock deformation and magmatic activity during orogenic events.
Article
Geology
Jan Varga, Tom Raimondo, Laura Morrissey, David E. Kelsey, Martin Hand
Summary: The study discusses the Entia Gneiss Complex in central Australia and its metamorphic evolution differences with the Harts Range Group, as well as its relationship with the Alice Springs Orogeny and local dome formation.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Wei-(RZ) Wang, Yue Zhao, Chunjing Wei, Nathan R. Daczko, Xiaochun Liu, Wenjiao Xiao, Zhiyong Zhang
Summary: The granulites in the Larsemann Hills have undergone complex metamorphic evolution and exhibit high-temperature conditions, suggesting a widespread distribution of high heat flow and potential UHT metamorphism in the Prydz Bay region. This study provides important insights into the tectonic and metamorphic evolution of East Antarctica.
JOURNAL OF PETROLOGY
(2022)
Article
Chemistry, Analytical
Casey L. Doolette, Daryl L. Howard, Nader Afshar, Cameron M. Kewish, David J. Paterson, Jianyin Huang, Stefan Wagner, Jakob Santner, Walter W. Wenzel, Tom Raimondo, Alexander T. De Vries Van Leeuwen, Lei Hou, Frederik van der Bom, Han Weng, Peter M. Kopittke, Enzo Lombi
Summary: Synchrotron-based X-ray fluorescence microscopy (XFM) analysis is a powerful technique for visualizing elemental distributions in various sample types. We developed a novel approach using two fluorescence detectors in tandem to acquire two sets of XFM data simultaneously, achieving high throughput and scanning large samples in XFM experiments.
ANALYTICAL CHEMISTRY
(2022)
Article
Geochemistry & Geophysics
Antoine Godet, Tom Raimondo, Carl Guilmette
Summary: This research reports on the discovery of atoll-shaped garnets in the New Quebec Orogen in Canada, and investigates their formation using petrography, EPMA, and LA-ICP-MS maps. The study suggests that the growth of these garnets is best explained by kinetic control and rapid growth involving Rayleigh fractionation of trace elements. The research highlights the importance of assessing the formation mechanisms on a case-by-case basis and using complementary tools such as trace element mapping.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Geology
Samuel Angiboust, Tom Raimondo
Summary: We report the discovery of rare eclogite-facies vugs in the western European Alps, which are millimeter- to centimeter-sized pockets. Thermodynamic modeling explains the formation of these vugs and suggests the presence of significant amounts of fluids that can influence volatile recycling in the Earth's mantle.
Article
Geochemistry & Geophysics
Ryan Portner, Brian M. Dreyer, David A. Clague, Nathan R. Daczko, Paterno R. Castillo
Summary: The discovery of rhyolite along the submarine segments of the mid-ocean ridge system suggests that these rocks formed through extreme crystal fractionation of primary mid-ocean ridge basalt. Analysis of trace elements and isotopes indicates minimal involvement of continental lithosphere or hydrated oceanic crust in the formation process.
JOURNAL OF PETROLOGY
(2022)
Article
Geosciences, Multidisciplinary
Alexander T. De Vries Van Leeuwen, Laura J. Morrissey, Tom Raimondo, Martin Hand
Summary: Metamorphic rocks from the Broken Hill Block in the Curnamona Province of south-central Australia have undergone a prolonged period of high thermal gradient metamorphism and anatexis. This study presents geochronological and geochemical data to develop a petrochronological model for the metamorphic evolution of the region. The results indicate an early phase of high-temperature-low-pressure metamorphism followed by peak metamorphism involving wholesale anatexis. The prolonged suprasolidus conditions suggest that radiogenic heating may have played a major role in this metamorphic process.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
Jan Varga, Tom Raimondo, Martin Hand, Stacey Curtis, Nathan Daczko
Summary: The Entia Gneiss Complex is a Paleoproterozoic basement terrane in Australia that underwent fluid-catalysed transformation and formed a migmatitic gneiss dome during the Alice Springs Orogeny. Pegmatite emplacement occurred during the late stages of the orogeny, with the oldest generation dating back to 1770Ma and subsequent generations ranging between 360 and 300Ma. The development of a crustal-scale duplex system and hydrous melting of the basement slab facilitated the formation of the gneiss dome.
Article
Geosciences, Multidisciplinary
R. L. Gardner, N. R. Daczko, S. Piazolo
Summary: Oceanic core complexes provide valuable insights into deep processes at slow and ultra-slow-spreading mid-ocean ridges. This study identifies certain features, such as secondary minerals and microstructural evidence, that can be used to recognize oceanic crust fluxed with external melt. The presence of secondary olivine in gabbros is shown to be a reliable indicator of melt-rock interaction during deformation-assisted melt migration.
AUSTRALIAN JOURNAL OF EARTH SCIENCES
(2023)
Editorial Material
Geochemistry & Geophysics
Samuel Angiboust, Aitor Cambeses, Ake Fagereng, Luca Menegon, Frieder Klein, Tom Raimondo, Cecile Prigent
Article
Geochemistry & Geophysics
Zhen-Min Ge, Xiao-Long Huang, Wei Xie, Tobias W. Hofig, Fan Yang, Yang Yu, S. Khogenkumar Singh
Summary: The mantle source composition of the nascent oceanic crust in the central part of the Gulf of California has been investigated using basaltic glass samples. These samples show trace element patterns similar to enriched mid-ocean ridge basalts, suggesting that the nascent oceanic crust in the Guaymas Basin might be generated through partial melting of a depleted mantle source metasomatized by subducted slab materials.
Article
Geochemistry & Geophysics
Jean-Michel Brazier, Katja E. Goetschl, Martin Dietzel, Vasileios Mavromatis
Summary: This study estimated the distribution coefficient of Zn2+ between calcite/aragonite and reactive fluids and found that the growth rate strongly influences D-Zn(2+) in both minerals. Additionally, a linear correlation was found between D-Zn(2+) and the saturation degree of the reactive fluid.
Article
Geochemistry & Geophysics
Ming Lei, Michele Lustrino, Jifeng Xu, Zhiqiang Kang, Zhengfu Guo, Jianlin Chen
Summary: This study presents a comprehensive geochronological, mineralogical, and geochemical analysis of olivine leucitites in the Maiga area of southern Tibet, suggesting that these rocks originate from a carbonated peridotite mantle source and highlighting the possibility of carbonates being recycled deep into the mantle during continental subduction.
Article
Geochemistry & Geophysics
Yuntao Ye, Xiaomei Wang, Huajian Wang, Haifeng Fan, Zhigang Chen, Qingjun Guo, Ziteng Wang, Chaodong Wu, Donald E. Canfield, Shuichang Zhang
Summary: Phosphorus is an essential element for life and its cycle in the ocean is closely connected with the carbon and oxygen cycles. The study of phosphate oxygen isotopes can provide insights into various reactions related to phosphorus. By analyzing carbonate fluorapatite samples from the Mesoproterozoic Era in North China, it was found that the oxygen isotope values were lower compared to modern samples, indicating a warmer climate during that time period and a potential reason for the scarcity of phosphorite.
Article
Geochemistry & Geophysics
Vincent Busigny, Oanez Lebeau, Didier Jezeduel, Carine Chaduteau, Sean Crowe, Magali Ader
Summary: This study conducted high-precision Mo isotope research on hydrothermal metal sulfides from a porphyry copper deposit in Southwest China and found that different stages of mineralization have distinct Mo isotope compositions, providing valuable insights into the behavior of Mo isotopes in magmatic-hydrothermal systems.
Article
Geochemistry & Geophysics
Min Ji, Xiao-Ying Gao, Yong-Fei Zheng, Bing Gong
Summary: The study examines the anatectic mechanisms in the Himalayan orogen, finding that pressure and temperature control the reaction, while water content mainly affects the solid-phase composition. Dehydration and hydration melting likely occur at different depths in the crust. This research provides important insights into the melting processes in collisional orogens.