Article
Geochemistry & Geophysics
Kun-Yan Wu, Biao Liu, Qian-Hong Wu, She-Fa Chen, Hua Kong, Huan Li, Safiyanu Muhammad Elatikpo
Summary: This study used trace elements, oxygen isotopic compositions, and U-Pb isotopes to trace the tungsten metallogenic processes and genesis of the Shizhuyuan W-Sn deposit. The results indicated that scheelite formed in multiple stages of fluid activities and is associated with the Qianlishan granite.
JOURNAL OF GEOCHEMICAL EXPLORATION
(2023)
Article
Geochemistry & Geophysics
Brenden J. Fischer-Femal, Gabriel J. Bowen
Summary: This study developed a semi-mechanistic model to explain factors affecting carbon and oxygen isotope values in pedogenic carbonates, which showed strong spatial variation globally. The model was validated and optimized using modern data, offering a new framework for interpreting paired carbon and oxygen isotope data from ancient pedogenic carbonates.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geology
Marshall C. Palmer, Emma J. Scanlan, James M. Scott, Lauren Farmer, Daniel Pickering, Victoria J. Wilson, Marcus Oelze, Dave Craw, Petrus J. le Roux, Yan Luo, D. Graham Pearson, Malcolm R. Reid, Claudine H. Stirling
Summary: The Otago Schist in New Zealand contains two types of tungsten mineralization, proximal and distal. The proximal mineralization occurs in sub- to lower-greenschist facies rocks and consists of quartz-calcite veins with minor scheelite and sulfides. The distal deposits are hosted in major crustal discontinuities within higher-grade metasedimentary rocks and are associated with abundant sulfides and gold. The scheelite in these two types of mineralization show geochemical differences, with the proximal occurrences being more heterogeneous in trace element and strontium isotope compositions compared to the more uniform scheelite in the distal deposits. The data suggest that tungsten mobility in the Otago Schist involved local-scale mobilization of W in the shallow crust followed by regional leaching and homogenization at higher temperatures.
ORE GEOLOGY REVIEWS
(2022)
Article
Geochemistry & Geophysics
D. Smrzka, J. Zwicker, Y. Lu, Y. Sun, D. Feng, P. Monien, G. Bohrmann, J. Peckmann
Summary: Trace elements in authigenic carbonates are influenced by ambient redox conditions, showing site-specific patterns and mineralogy dependence. The presence of dissolved sulfide in Black Sea seep environments affects carbonate mineralogy and trace element speciation and content. Strong euxinic conditions favor low-magnesium calcite formation, while fluctuating redox conditions promote aragonite cement precipitation.
Article
Geosciences, Multidisciplinary
Miquela Ingalls, Kathryn E. Snell
Summary: Carbonates are prevalent in the geological record and offer stable isotope-based proxies for ancient climatic conditions and environmental histories. A hierarchical suite of techniques is proposed to comprehensively assess alterations in carbonates and identify preserved textures containing valuable environmental information. These techniques include optical and cathodoluminescence microscopy, secondary ionization mass spectrometry (SIMS), PIC mapping, and other technologies for distinguishing primary and altered fabric at finer spatial resolutions.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Ning Zhu, Yingchang Cao, Kelai Xi, Songtao Wu, Rukai Zhu, Miaomiao Yan, Shunkang Ning
Summary: Sandy-conglomerate reservoirs have become a major target for oil and gas exploration, with carbonate cements forming at various stages of diagenesis recording geological fluid information. A recent study in the Junggar Basin revealed a billion-ton sandy conglomerate oil field with diverse carbonate cements. Isotope analysis and fluid inclusion measurements showed the impact of different CO2 injections on reservoir quality.
JOURNAL OF EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Chao Duan, Yanhe Li, Jingwen Mao, Qiu Wan, Sheng He, Conglin Wang, Bingyang Yang, Kejun Hou
Summary: This study distinguishes the mineralization related and unrelated formations based on zircon Hf-O isotope and trace element analyses, revealing the magma evolution and fertility of the iron oxide-apatite (IOA) deposits in the Ningwu ore district. The Mesozoic volcanic rocks in Ningwu have three sources: enriched mantle, Archean crystalline basement, and Neoproterozoic crustal materials. The magmatic sources divide the four volcanic formations into two groups: the Longwangshan and Dawangshan formations, and the younger Gushan and Niangniangshan formations. Factors such as moderate magmatic fO2 values, F-richness, high water contents, high proportions of enriched mantle materials, and a higher degree of magma evolution may affect the fertility of the magma for IOA deposit formation.
Article
Geography, Physical
Yanan Cheng, Can Zhang, Yanling Li, Xiangzhong Li, Weiguo Liu, Cheng Zhao
Summary: Oxygen isotopes from lacustrine carbonate have been widely used to understand changes in monsoon rainfall and variability in the Asian monsoon region. This study evaluates the potential evaporative enrichment effect on lake water isotope compositions and finds that it has played a significant role in the Holocene. The findings highlight the importance of considering evaporation effects when studying long-term changes in terrestrial water balance.
GLOBAL AND PLANETARY CHANGE
(2023)
Article
Geochemistry & Geophysics
Axel Hofmann, Robert Bolhar, Anton B. Kuznetsov, Jaganmoy Jodder, Mike Butler, Ai Nguyen
Summary: The Neoarchaean greenstone belts in Zimbabwe contain limestone successions with microbial fossils, ranging in age from -2.82 to 2.68 Ga. Among these, the best-preserved successions are found in the Bulawayo and Belingwe greenstone belts, which were subjected to lower greenschist facies metamorphism. The carbonate rocks mainly consist of calcite, with some dolomite and variable amounts of siliciclastic detritus.
Article
Geochemistry & Geophysics
Marsha W. French, Richard H. Worden, Hubert E. King, William C. Horn, William A. Lamberti, Jennifer D. Shosa
Summary: The study examines the relationships between quartz cement, chalcedony/amorphous silica, and microcrystalline quartz in sandstones, with implications for the porosity of deeply buried sandstones. It is suggested that chalcedony and microcrystalline quartz developed during cooling of flowing formation water, with higher delta O-18 values indicating considerable water-rock interaction typical of basin-center waters. The presence of duplicate layers suggests two thrust-induced fluid expulsion events in the Coniacian to Campanian.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geosciences, Multidisciplinary
Rui-Chang Tan, Yong-Jun Shao, Han-Tao Wei, Jun-Ke Zhang, Meng-Da Yu, Yi-Qu Xiong
Summary: This study determined the major and trace element compositions of the newly-identified apatite from the Pb-Zn ores in the Huayuan orefield. The apatite samples are of hydrothermal origin and have distinct characteristics from typical magmatic and purely hydrothermal apatites. The mixing of ore-forming fluids from different sources may have triggered significant metal ore deposition.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geology
Jaeguk Jo, Toshiro Yamanaka, Dongbok Shin
Summary: Ion adsorption-type rare earth element (REE) mineralization commonly occurs with kaolinite and halloysite in the weathered crusts of granitoid rocks. The enrichment of REEs in the clay fractions is higher under weakly acidic conditions (pH 5-7) but decreases sharply under more acidic conditions (pH <4). The geochemical characteristics and the features of nitrogen behavior in the bulk rock and its clay fraction contribute to our understanding of the genesis of ion adsorption-type REEs mineralization in the weathered crusts of granitoid rocks.
ORE GEOLOGY REVIEWS
(2023)
Article
Geology
Bijie Peng, Mingyue He, Mei Yang, Xi Liu, Xinhao Sui, Kaiyue Sun, Shaokun Wu
Summary: The Jian forsterite jade, named after its rich end-member forsterite content, is a new type of jade mainly composed of forsterite, serpentine, and other minerals. The formation process involves high-temperature prograde and low-temperature retrograde metamorphic stages, with distinct trace element signatures indicating a siliceous fluid-mediated decarbonation process.
ORE GEOLOGY REVIEWS
(2022)
Article
Microbiology
Maja Ivanic, Martina Furdek Turk, Zdenko Tkalcec, Zeljka Fiket, Armin Mesic
Summary: This study investigated the composition of major, trace, and rare earth elements in 15 different species of wild edible mushrooms and their uptake affected by urban pollution. The results showed a wide variability in the composition of mushrooms, influenced by multiple factors. Risk assessment revealed potential adverse health effects from consuming excessive amounts of mushrooms studied, whether from urban areas or forests.
Article
Geochemistry & Geophysics
Qi Yu, Zhigao Wang, Qingfei Sun, Keyong Wang
Summary: This study provides insights into the composition, substitution mechanisms, and source of sulfur of pyrite in the Beiwagou Pb-Zn deposit using in situ trace element analyses and sulfur isotopes. The deposit is characterized by the occurrence of different pyrite types and a likely thermochemical sulfate reduction origin.
Article
Geosciences, Multidisciplinary
Samuel Yaw Danso, Yi Ma, Adams Osman, Isaac Yeboah Addo
Summary: This study conducted a spatial assessment and mapping of flood hazards in the Sekondi-Takoradi Metropolis (STM) of Ghana using the Analytical Hierarchy Process (AHP) and geographical information system. The results indicate that about 12% of STM lands are in very high flood zones and 24% are in high flood zones. The lower portions of STM are identified as the most susceptible to inundation. These findings provide valuable insights for effective flood planning and prevention in STM.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Kesyton Oyamenda Ozegin, Stephen Olubusola Ilugbo
Summary: The study utilizes analytical hierarchical process and geoinformatics-based approaches to define groundwater potential zones in Edo State, Nigeria. The results show that high groundwater potential zones are mainly located in Edo-central and isolated portions of Edo-south, while low to very low potential zones are found in the study's northern region.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Maham Eboubekrine Sedigh, Houssa Ouali, Michel Jebrak, Abdelkader Mokhtari
Summary: The carbonatites from the Richat dome in Mauritania are unique and underdocumented geological features. This study provides insight into the mineralogy and petrogenesis of the carbonatites, revealing three identified types and their association with spinel-bearing peridotite. The geochemical characteristics of the Richat carbonatites are similar to other Cretaceous alkaline carbonatite occurrences in different regions, suggesting a common geological process. The reactivation of a deep pan-African lineament is considered a fundamental factor in the formation of the Richat carbonatites.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Riadh Aouissi, Gamal Mohamed El Qot, Sihem Salmi-Laouar, Catalina Gomez-Espinosa, Blanca E. Buitron-Sanchez
Summary: Twenty-one gastropod species have been identified in the Cenomanian deposits of Bellezma-Aures mountains, eastern Saharan Atlas, Algeria, with four of them recorded for the first time in the Batna mountains. These gastropods are mainly found in the 'Marnes de Smail' Formation, and their community changes may be attributed to minor sea-level fluctuations, sedimentation rate variations, and hydrodynamics. The paleobiogeographic distribution of these gastropod assemblages indicates a tethyan affinity and faunal exchange during that time interval.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Behnam Esmaeili, Sirous Hosseinzadeh, Ali Kadkhodaie, David A. Wood, Samira Akbarzadeh
Summary: This research applies image analysis and clustering algorithms to estimate porosity and permeability of petroleum reservoir rocks, and demonstrates that the results from image analysis are consistent with traditional analysis methods, with acceptable correlation. In addition, different depositional environments and hydraulic flow units are identified through image analysis.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Jianqi Zhuang, Jianbing Peng, Zhenhong Li, Yanqiu Leng, Xinghua Zhu, Weiliang Huang, Zhijie Jia, Yang Liu, Yi Zhu
Summary: The study on gully erosion in the East African Rift Valley of Kenya reveals that human activities and rainstorms are the main factors causing erosion. Gully erosion poses a serious threat to the ecological environment, particularly the man-made and fissure-induced gullies that should be further investigated.
JOURNAL OF AFRICAN EARTH SCIENCES
(2024)