Article
Geochemistry & Geophysics
Quentin Bollaert, Mathieu Chasse, Artur Bastos Neto, Benoit Baptiste, Alexandra Courtin, Laurence Galoisy, Olivier Mathon, Cecile Quantin, Delphine Vantelon, Georges Calas
Summary: This study investigates the behavior and enrichment mechanisms of niobium (Nb) during weathering processes in the critical zone. The results reveal that the fate of Nb released from pyrochlore is controlled by the secondary phases formed during weathering, with different host minerals for Nb in different horizons. The findings challenge the common assumption that Nb is geochemically invariant in the critical zone and provide a new model for the formation of Nb-enriched laterites.
Article
Geochemistry & Geophysics
Rui Bao, Xuefen Sheng, Chenglong Li, Can Cui, Hao Yan, Junfeng Ji, Jun Chen
Summary: The application of Δ47 in land snails as a temperature proxy is relatively rare compared to other carbonate materials. This study cultured two species of land snails under controlled temperature conditions and found a significant negative correlation between shell Δ47 values and culturing temperature within their respective optimum temperature ranges. However, shell Δ47 values at lower temperatures showed a negative deviation, which may be attributed to a vital effect associated with CO2 degassing during carbonate precipitation.
Article
Geochemistry & Geophysics
Anzhou Li, Sensen Wu, Huan Chen, Zhenhong Du, Qunke Xia
Summary: This study introduces the utilization of machine learning methods to classify the diffusion of water in clinopyroxene, with Shapley theory being integrated to explain the classification results. The findings demonstrate the dominant role of sodium in the diffusion process, highlighting its significance in understanding geological phenomena.
Article
Geochemistry & Geophysics
Colin Ferrari, Eleonore Resongles, Marina Hery, Angelique Desoeuvre, Remi Freydier, Sophie Delpoux, Odile Bruneel, Corinne Casiot
Summary: The oxidation of antimonite to antimonate plays a crucial role in controlling the mobility of antimony in aquatic systems. This study investigates the fractionation of antimony isotopes during the oxidation process under mining-relevant concentrations. The results show that the fractionation of antimony isotopes is influenced by experimental conditions and reaction pathways. While antimony isotopes have the potential to serve as process tracers in water, further research and comparison with natural systems are needed.
Article
Geochemistry & Geophysics
Madjid Abbasi, Abdolreza Ghods, Mahdi Najafi, Saeed Abbasy, Meysam Amiri, Esmaeil Shabanian, Mohanna Kheradmandi, Jamal Asgari
Summary: The Makran Subduction Zone is divided into western and eastern regions, with the majority of megathrust earthquakes occurring in the eastern region. This study investigates why the western region experiences a lack of megathrust earthquakes and lower seismicity rate compared to the eastern region. By analyzing GPS data, the researchers found that the coupling between the subducting Arabian oceanic plate and the overriding plate in the western region is significantly weaker than in the eastern region. Furthermore, the rate of strain accumulation within the megathrust zone in the western region is much smaller than in the eastern region. The study also reveals a right-lateral motion across the transition zone between the Zagros and Makran. These findings suggest a lower earthquake hazard in the western Makran due to the northward movement of the overriding Lut block and the reduced seismic coupling between the subducting and overriding plates, while indicating a higher earthquake hazard in the transition zone between the Zagros and Makran.
Article
Geochemistry & Geophysics
Yanna Zhao, Miao Zhang, Yonghong Duan, Xinglin Lei, Qiaoxia Liu
Summary: The Changning area has experienced an increase in seismic activity, with distinct seismogenic structures and earthquake mechanisms. The earthquakes are mainly distributed in anticlines, injection areas, and around salt mining wells. The locations and velocity characteristics of the earthquakes are influenced by shallow terrain, syncline structures, and the distribution of fluids and gas reservoirs.
Article
Geochemistry & Geophysics
Jian Guo, Xuelin Qiu, Haibo Huang, Hui Jiang, Enyuan He
Summary: By processing the data obtained from OBS2019-2 in the Liyuexi Trough of the South China Sea, researchers were able to determine the P-wave and S-wave velocity structures of the crust in this region, providing valuable information about its geological composition and structure.
Article
Geochemistry & Geophysics
Yuan Gao, Wei Qu, Qin Zhang, Jiuyuan Li, Da Li, Yuhao Wang, Ming Hao
Summary: North China has a history of devastating earthquakes, and it is important to identify regions with high potential for future large earthquakes. This study combines seismic records and geodetic observations to comprehensively assess the earthquake potential. The results reveal that the western border of the Ordos Block and the Tangshan fault zone have high seismic hazard potentials.
Article
Geochemistry & Geophysics
Hao Kuo-Chen, Dennis Brown, Szu-Ying Lai, Jue-Ying Chen
Summary: This article investigates the internal sedimentary and tectonic features of the Longitudinal Valley through seismic profiles, revealing minimal internal deformation and sedimentary characteristics. The presence of inclined reflections suggests a marine or lacustrine environment, with sediment mainly sourced from the Central Range.
Article
Geochemistry & Geophysics
Yue Sheng, Sheng Jin, Matthew J. Comeau, Zengqian Hou, Letian Zhang, Wenbo Wei, Gaofeng Ye
Summary: By examining the electrical resistivity models of the Dinggye region and comparing them with geological and geochemical evidence, this study reveals the relationship between crustal migration, north-south-trending normal rifting, and deep plunging subduction. The findings suggest that the southern migration of lithospheric materials likely played a role in the evolution of rifts in the Tethys-Himalaya terrane, influenced by the uplifting and cooling of gneiss domes.
Article
Geochemistry & Geophysics
Ana Simon-Muzas, Antonio M. Casas-Sainz, Ruth Soto, Emilio L. Pueyo, Elisabet Beamud, Belen Oliva-Urcia
Summary: This study presents a detailed paleomagnetic analysis of volcanic rocks and red beds from the Late-Carboniferous-Permian series in the Cadi Basin. The results provide reliable paleomagnetic directions and indicate the presence of magnetite and hematite in these rocks. The study also suggests that the main magnetization is of Permian age in the red beds and may represent primary magnetization or early remagnetization in the Late Carboniferous volcanic rocks.
Article
Geochemistry & Geophysics
Da Zhang, Yuhang Guo, Qinlin Yang, Shu Wang
Summary: Volcanic oil and gas resources are abundant and constructing a reasonable petrophysical model is crucial for predicting reservoirs. This paper proposes a method to build equivalent petrophysical models for complex volcanic rocks using conventional logging curves, achieving accurate results in practical applications.
Article
Geochemistry & Geophysics
Chonghao Jia, Yuke Fan, Jialin Chi, Christine Putnis, Chuanqin Huang, Wenjun Zhang
Summary: This study investigates the adsorption mechanism of inorganic phosphate and organic phytate on nano-clay, revealing the impact of factors such as pH, ionic strength, and dissolved organic matter on the adsorption capacity. Findings show that laponite's adsorption capacity decreases with increasing pH, while the presence of dissolved organic matter inhibits phosphorus adsorption.
Article
Geochemistry & Geophysics
Yumeng Wang, Guoxiang Chi
Summary: Thermal convection and fluid mixing play crucial roles in the formation of mineral deposits, however, their relationships and impacts are not well understood. This study investigates the formation of high-grade unconformity-related uranium deposits in the Athabasca Basin by combining thermal convection and fluid mixing.
Article
Geochemistry & Geophysics
Neha Mehta, Delphine Vantelon, Juliette Gaetan, Alejandro Fernandez-Martinez, Ludovic Delbes, Cynthia Travert, Karim Benzerara
Summary: The short-range order of bacterial intracellular amorphous calcium carbonates (ACC) remains largely unexplored. In this study, X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies were used to investigate the calcium speciation and coordination environment in intact cells of diverse ACC-forming cyanobacteria. The findings reveal that XANES is effective in detecting ACC in intact cells and that the short-range order of cyanobacterial ACC is different from eukaryotic ACC, resembling monohydrocalcite. These results provide insights into the fate of cyanobacterial ACC and the role of ACC-forming cyanobacteria in the biogeochemical cycle of calcium.
Article
Geochemistry & Geophysics
Xueqing Yin, Xinfu Zhao, Runsheng Yin, Lingjian Gao, Changzhou Deng, Zhendong Tian, Shengren Chang, Bernd Lehmann
Summary: This study investigates the Hg isotopic compositions of ore minerals from IOCG deposits in the Kangdian region, South China, and finds that the Hg components in the IOCG system are dominated by a lithospheric mantle source. The results shed light on deep Hg cycling and confirm the use of Hg isotopes as a tracer for metal sources in hydrothermal ore systems.
Article
Geochemistry & Geophysics
Stefanie Eichinger, Ronny Boch, Andre Baldermann, Katja Goetschl, Robert Wenighofer, Rene Hoffmann, Franziska Stamm, Dorothee Hippler, Cyrill Grengg, Adrian Immenhauser, Martin Dietzel
Summary: This study investigates the calcite-to-aragonite transition and intergrowth mechanism in carbonate sinter formation using a historic subsurface adit in Austria as a natural laboratory. The results show that low-Mg calcite initially nucleates and progressively grows into high-Mg calcite due to CO2 degassing, and then aragonite nucleates and inhibits further calcite growth on the available Mg-calcite surfaces. The findings highlight the importance of reaction kinetics, chemical evolution, and environmental changes in understanding the formation of calcite-aragonite sequences in carbonate sedimentary deposits.
Review
Geochemistry & Geophysics
Wei Fang, Li-Qun Dai, Zi-Fu Zhao
Summary: The molybdenum (Mo) isotope system is a powerful tool for tracing recycled crustal components in volcanic rocks. This study synthesizes Mo isotope and other geochemical data for global intraplate basalts, providing insights into Mo recycling in Earth's deep mantle. The results show that the Mo isotopes in intraplate basalts are highly variable, with some coming from recycled dehydrated oceanic crustal components and others being dragged by downgoing slab into the deep mantle.
Article
Geochemistry & Geophysics
Michaela Hlozkova, Michaela Vasinova Galiova, Pavel Coufalik, Karel Breiter, Radek Skoda, Matej Brezina, Martin Brtnicky, Jindrich Kynicky
Summary: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a unique technique used for in situ analysis of solid samples. This paper reviews the analysis of tin in geological samples and summarizes the limitations that may cause inaccurate outcomes. The experimental results demonstrate the extent of cross-contamination caused by material ablation and the impact of contamination on background progress.
Article
Geochemistry & Geophysics
Xiao-Yun Nan, Fei Wu, Hui-Min Yu, Jin-Ting Kang, Yong-Jun Gao, Fang Huang
Summary: This study investigates the behavior of barium isotopes during low-temperature seawater alteration and high-temperature hydrothermal alteration processes in the oceanic crust. The results show that the barium isotope compositions of the volcanic section and sheeted dike complex have large variations, possibly due to modification by seawater and hydrothermal fluid. The samples from the plutonic complex display lighter barium isotope compositions, reflecting the influence of late magmatic fluids. The recycling of the altered oceanic crust could result in barium isotope heterogeneity in the mantle.
