Journal of Earth Science最新文献_第6页

Debris Flow Susceptibility Evaluation in Meizoseismal Region: A Case Study in Jiuzhaigou, China 梅藏地震区泥石流易发性评估：中国九寨沟案例研究

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-022-1803-1

Yongwei Li, Linrong Xu, Yonghui Shang, Shuyang Chen

{"title":"Debris Flow Susceptibility Evaluation in Meizoseismal Region: A Case Study in Jiuzhaigou, China","authors":"Yongwei Li, Linrong Xu, Yonghui Shang, Shuyang Chen","doi":"10.1007/s12583-022-1803-1","DOIUrl":"https://doi.org/10.1007/s12583-022-1803-1","url":null,"abstract":"Jiuzhaigou is situated on a mountain-canyon region and is famous for frequent tectonic activities. An abundance of loose co-seismic landslides and collapses were produced on gullies after the Jiuzhaigou Earthquake on August 8, 2017, which was served as material source for debris flow in later years. Debris flow appears frequently which are seriously endangering the safety of people’s lives and properties. Even the earliest debris flow appeared in areas where no case ever reported before. The debris flow susceptibility evaluation (DFSE) is used for predicting the areas prone to debris flow, which is urgently required to avoid hazards and help to guide the strategy of preventive measures. Therefore, this work employs debris flow in Jiuzhaigou to reveal the characteristics of disaster-pregnant environment and to explore the application of machine learning in DFSE. Some new viewpoints are suggested: (i) Material density factor of debris flow is first adopted in this work, and it is proved to be a critical factor for triggering debris flows by sensitivity analysis method. (ii) Deep neural network and convolutional neural network (CNN) achieve relatively good area under the curve (AUC) values and are 0.021–0.024 higher than traditional machine learning methods. (iii) Watershed units combined with CNN-based model can achieve more accurate, reliable and practical susceptibility map. This work provides an idea for prevention of debris flow in mountainous lands.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"197 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Trace Element Mobility in Subducted Marble and Associated Eclogite: Constraints from UHP Rocks in the Shuanghe Area, Central-East China 俯冲大理岩及相关辉绿岩中微量元素的流动性：中国中东部双河地区超高压岩石的制约因素

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-022-1692-3

Xingao Hou, Zhiqiang Yu, Shefa Chen, Lei Liu, Yilin Xiao

{"title":"Trace Element Mobility in Subducted Marble and Associated Eclogite: Constraints from UHP Rocks in the Shuanghe Area, Central-East China","authors":"Xingao Hou, Zhiqiang Yu, Shefa Chen, Lei Liu, Yilin Xiao","doi":"10.1007/s12583-022-1692-3","DOIUrl":"https://doi.org/10.1007/s12583-022-1692-3","url":null,"abstract":"In order to decipher element mobility in UHP meta-sedimentary rocks in the continental subduction zone, major and trace element compositions are investigated for a continuous profile from a representative UHP region in the Dabie Mountains. Among the lithologic contact zone, contents of K, Ca, LREE, and LILE exhibit varying degrees of downward trends in both marble and eclogite toward the contact zone, indicating that marble and their associated eclogite can release a large amount of K, Ca, and a small number of LILEs and LREEs. Titanite is the main Ti phase in both marble and eclogite. Titanite rims around rutile can occasionally be seen in eclogite. Contents of Ti and HFSE exhibit a well-coupled relation among marble and eclogite, indicating that substantial Ti and HFSEs were migrated from eclogite to marble, in accord with the capacity of a melt medium. Rutiles and titanites in marble exhibit a relatively limited variation in Nb/Ta ratios (12.9–16.2), similar to those of titanites in eclogite (14.2–16.7), which demonstrates that rutiles and titanites in marble were sourced from eclogite because of short-distance migrations of Ti and HFSEs. According to the P-T path and the temperature and pressure conditions of the peak metamorphism reported by previous studies, the eclogite associated with marble may not form supercritical fluids in the subduction zone because of the addition of carbonate minerals.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"23 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preliminary Results of the Seismicity Monitoring Experiment around the 2019 Mw5.4 Earthquake Epicenter in the Central South China Sea Basin 2019 年南海盆地中部 Mw5.4 级地震震中附近地震监测试验的初步结果

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-021-1604-y

Wenfei Gong, Aiguo Ruan, Xiongwei Niu, Zhenjie Wang, Pingchuan Tan, Xiaodong Wei, Wei Wang, Zhengyi Tong, Liqun Cheng, Fansheng Kong, Shaoping Lu, Jianke Fan, Weiwei Ding, Jinyao Gao, Chunguo Yang, Jiabiao Li

{"title":"Preliminary Results of the Seismicity Monitoring Experiment around the 2019 Mw5.4 Earthquake Epicenter in the Central South China Sea Basin","authors":"Wenfei Gong, Aiguo Ruan, Xiongwei Niu, Zhenjie Wang, Pingchuan Tan, Xiaodong Wei, Wei Wang, Zhengyi Tong, Liqun Cheng, Fansheng Kong, Shaoping Lu, Jianke Fan, Weiwei Ding, Jinyao Gao, Chunguo Yang, Jiabiao Li","doi":"10.1007/s12583-021-1604-y","DOIUrl":"https://doi.org/10.1007/s12583-021-1604-y","url":null,"abstract":"On September 5, 2019, a moderate earthquake of Mw5.4 unexpectedly occurred in the apparently quiescent central basin of the South China Sea. We immediately carried out a seismicity monitoring experiment around the epicenter by using broadband ocean bottom seismometers (OBS) for the following three scientific targets. The first is knowing the earthquake seismogenic mechanism, fault structure and further development. The second is finding the role of the residual spreading ridge playing in earthquake processes and further revealing the deep structures of the ridge directional turning area. The third is confirming the existence and significance of the so called “Zhongnan fault”. This paper reports the preliminary results of the first phase experiment. Five OBSs were deployed for seismicity monitoring with a duration of 288 days, but only three were recovered. Micro-earthquakes were firstly detected by an automatic seismic phase picking algorithm and then were verified by analyzing their seismic phases and time-frequency characteristics in detail. A total of 21, 68 and 89 micro-earthquakes were picked out from the three OBSs respectively within the distance of 30 km. The dominant frequency of these micro-earthquakes is 12–15 Hz, indicating tectonic fracturing. During the first two months after the mainshock the seismicity was relatively stronger, and micro-earthquakes were still occurring occasionally till the end of observation, indicating the epicenter area is active. We used Match&Locate method to locate 57 micro-earthquakes preliminarily. Their spatial distribution shows that the seismicity is developed mainly along the NE direction roughly parallel to the residual ridge with depth variations between 10–20 km.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"291 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic Stability and Fuzzy Reliability Analysis of Toppling Perilous Rock Under Seismic Excitation 地震激励下倾覆危岩的动态稳定性和模糊可靠性分析

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-022-1740-z

Linfeng Wang, Jixu Zhang, Wanchun Xia, Xiaoming Huang, Guojin Tan

{"title":"Dynamic Stability and Fuzzy Reliability Analysis of Toppling Perilous Rock Under Seismic Excitation","authors":"Linfeng Wang, Jixu Zhang, Wanchun Xia, Xiaoming Huang, Guojin Tan","doi":"10.1007/s12583-022-1740-z","DOIUrl":"https://doi.org/10.1007/s12583-022-1740-z","url":null,"abstract":"To predict the occurrence of the collapse disaster in toppling perilous rock under the action of bidirectional earthquakes, the dynamic stability and fuzzy reliability calculation method of toppling perilous rock under the action of bidirectional earthquakes is proposed. First, the mass viscoelasticity model is used to simulate two main control surfaces of toppling perilous rock, the seismic dynamic response model and motion equation of toppling perilous rock are established based on the D’Alembert principle, and the Newmark-β method is used to solve the dynamic motion equation. Then, the instability event of toppling perilous rock is considered a fuzzy event, the membership function expression of the stability coefficient of toppling perilous rock is determined based on the fuzzy failure criterion, the calculation equations of the toppling perilous rock dynamic stability coefficient and fuzzy reliability are established, and the fuzzy reliability evaluation method based on the probability distribution of reliability is proposed. Finally, the influence of different superposition modes of seismic excitation on the fuzzy reliability of toppling perilous rock is analyzed. The calculation results of toppling perilous rock in the engineering case show that the fuzzy reliability calculated after considering the fuzzy failure criterion is reduced by 10.73% to 25.66% compared with the classical reliability. Considering the bidirectional seismic excitation, the fuzzy reliability of toppling perilous rock is reduced by 5.46% to 14.89%. Compared with using the acceleration peak time encounter mode to superpose the seismic excitation, the fuzzy reliability of toppling perilous rock is reduced by 3.4% when the maximum action effect time encounter mode is adopted.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"9 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characteristics of Paleontological Communities in Surface Sediments of the Southern South China Sea and Their Paleoclimatic and Paleoenvironmental Significance 中国南海南部表层沉积物中的古生物群落特征及其古气候和古环境意义

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-023-1910-5

Jing Zhao, Li Zhang, Xiaoyan Wang, Jinglian Ge, Min Xu, Wei Chen, Mao Luo, Qianyong Liang, Qiuhua Yu, Shuaibing Luo, Wenkun Qie

{"title":"Characteristics of Paleontological Communities in Surface Sediments of the Southern South China Sea and Their Paleoclimatic and Paleoenvironmental Significance","authors":"Jing Zhao, Li Zhang, Xiaoyan Wang, Jinglian Ge, Min Xu, Wei Chen, Mao Luo, Qianyong Liang, Qiuhua Yu, Shuaibing Luo, Wenkun Qie","doi":"10.1007/s12583-023-1910-5","DOIUrl":"https://doi.org/10.1007/s12583-023-1910-5","url":null,"abstract":"Understanding the spatial and temporal distribution of different paleontological communities in the southern South China Sea (SCS) is fundamental to explore its paleoclimatic and paleoenvironmental changes. In this study, foraminifera, pollen and diatoms from 100 surface sediment samples covering 40 000 km2 of sea floor in the southern SCS were comprehensively investigated in terms of their assemblage and distribution. The results showed the existence of abundant foraminifera and pollen in most of the samples, although diatom communities were relatively scarce. Foraminifera were dominated by G. sacculifer, G. menardii, G. ruber, while diatoms were characterized by T. simonsenii, T. nitzschioides and T. longissima, indicating a typical tropical marine environment. The pollen assemblages showed a better reflection of montane rainforest, tropical rainforest and mangrove. The spatial differences among foraminifera assemblages may indicate the effect of water depth and a warmer environment in the southeast part of the study area, while the spatial patterns of diatom and pollen assemblages imply the influence of coastal current. Our study also noted that the compositions of paleontological communities in the SCS can vary significantly in a short distance, and synthesized studies on multiple biological groups are needed to reconstruct the Quaternary climate and the oceanographic environment.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"17 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Zircon Hf Isotope Mapping for Understanding Crustal Architecture and Its Controls on Mineralization during Early Cretaceous in the Southern Great Xing’an Range, NE China 通过锆石 Hf 同位素测绘了解中国东北大兴安岭南部早白垩世地壳结构及其对成矿作用的影响

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-020-1100-9

Feng Yuan, Huanan Liu, Shengjin Zhao, Mingjing Fan

{"title":"Zircon Hf Isotope Mapping for Understanding Crustal Architecture and Its Controls on Mineralization during Early Cretaceous in the Southern Great Xing’an Range, NE China","authors":"Feng Yuan, Huanan Liu, Shengjin Zhao, Mingjing Fan","doi":"10.1007/s12583-020-1100-9","DOIUrl":"https://doi.org/10.1007/s12583-020-1100-9","url":null,"abstract":"Voluminous Early Cretaceous granitoids and associated large-scale ore deposits are distributed within the southern Great Xing’ an Range (SGXR), NE China. Based on previously published geochronology and zircon Hf-isotope data, Hf isotope mapping is undertaken to improve our understanding of crustal architecture and its controls on ore deposits. The ore-related Early Cretaceous granitoids were sourced predominantly from juvenile crust, with the involvement of variable proportions of ancient crustal materials. The crustal architecture, as inferred from Hf isotopic contour maps, indicates two distinct Hf isotopic domains in SGXR, including (1) a higher-εHf (+7 to +11) juvenile crust containing minor ancient crustal material, and (2) a lower-εHf (+2 to +6) juvenile crust containing a greater proportion of ancient crustal materials. The Hf isotopic maps identify links between crustal architecture and regional metallogeny. Copper deposits and other deposits with significant Cu production are restricted mainly to the higher-εHf juvenile crustal regions in the northern and eastern SGXR. Deposits dominated by other metals (e.g., Mo, Sn, W, Pb, Zn, and Ag) occur mainly in the lower- εHf juvenile crustal regions in the southern and western SGXR. Interaction between juvenile crust-derived melts and ancient crustal components played an important role on the distribution of various ore metals.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"62 18 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic Effect of Landslides Triggered by Earthquake: A Case Study in Moxi Town of Luding County, China 地震引发滑坡的动态效应：中国泸定县磨西镇案例研究

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-022-1806-y

Hongfu Zhou, Fei Ye, Wenxi Fu, Bin Liu, Tian Fang, Rui Li

{"title":"Dynamic Effect of Landslides Triggered by Earthquake: A Case Study in Moxi Town of Luding County, China","authors":"Hongfu Zhou, Fei Ye, Wenxi Fu, Bin Liu, Tian Fang, Rui Li","doi":"10.1007/s12583-022-1806-y","DOIUrl":"https://doi.org/10.1007/s12583-022-1806-y","url":null,"abstract":"The dynamic effect is a very important issue widely debated by scholars when studying the genetic and disaster-causing mechanisms of earthquake-triggered landslides. First, the dynamic effect mechanism and phenomena of earthquake-triggered landslides were summarized in this paper. Then, the primary types of dynamic effects were further used to interpret the Mogangling landslide in Moxi Town of Luding County, China. A field investigation, remote sensing, numerical calculation and theoretical analysis were carried out to illustrate the failure mechanism of slope rock masses affected by earthquakes. The interaction between seismic waves and slope rock masses and the induced dynamic effect of slope rock masses were primarily accounted for in the analysis. The slope topography, rock mass weathering and unloading characteristics, river erosion, regional seismogenic structure, and rock mass structure characteristics were also discussed. The results showed that the formation of the Mogangling landslide was mainly related to the high amplification effect of seismic acceleration and back slope effects, interface dynamic stress effects, and double-sided slope effects of seismic waves caused by the catastrophic Ms 7.75 Moxi Earthquake in 1786. The principles for the site and route selection of large-scale infrastructure in the planning stage and the scientific prevention of seismic geological disasters were proposed on the basis of the dynamic effect of earthquake-induced landslides.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characteristics and Genesis of Acid Drainage Contamination from a Rock Tunneling Project Site 岩石隧道工程现场酸性排水污染的特征和成因

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-021-1551-7

Yanyun Li, Zejiao Luo, Shihua Qi

{"title":"Characteristics and Genesis of Acid Drainage Contamination from a Rock Tunneling Project Site","authors":"Yanyun Li, Zejiao Luo, Shihua Qi","doi":"10.1007/s12583-021-1551-7","DOIUrl":"https://doi.org/10.1007/s12583-021-1551-7","url":null,"abstract":"While acid mine drainage (AMD) issues have become a topic of global concern, few studies have focused on acid drainage problems of non-mining activities. We conducted field research and a series of laboratory experiments to investigate the characteristics, release processes and formation of acid drainage contamination. Spoil rock samples and adjacent surface water, groundwater, soil and sediment samples were collected at a railway tunnel construction site in central China, and various parameters, such as the pH, mineral ion concentrations, and heavy metal concentrations, were measured. Based on the measured concentrations, surface water and sediments were seriously contaminated by acids, sulfate salts and heavy metals. Contamination in surface water showed a decreasing tendency as the distance from the spoils increased, while that in sediments showed a greater influence of coprecipitation and adsorption processes of heavy metal ions. The eluviation experiments of three rock samples indicated that R2 (silty fine sandstone) was the most likely major acid drainage contributor. Thiobacillus ferrooxidans was cultured and isolated from contaminated water to study the oxidation conditions during the release processes. The significant release of acid drainage when air and bacteria were both in the culture container suggested that oxygen and bacteria were necessary to produce acid drainage from spoils.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"37 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of Arroyo Verde Epithermal Deposit: Paragenesis, Mineral Geochemistry, Geochronology and Fluid Inclusions in Lower Chon Aike Volcanism, Argentina Arroyo Verde 热液矿床的特征：阿根廷 Chon Aike 下火山带的成因、矿物地球化学、地质年代和流体包裹体

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-023-1823-5

Cecilia Pavón Pivetta, Leonardo Benedini, Paulo Marcos, Ma. Agustina Cócola, Mercedes Virginia Barros, Daniel Gregori, Leonardo Strazzere, Anderson Costa dos Santos, Mauro C. Geraldes

{"title":"Characterization of Arroyo Verde Epithermal Deposit: Paragenesis, Mineral Geochemistry, Geochronology and Fluid Inclusions in Lower Chon Aike Volcanism, Argentina","authors":"Cecilia Pavón Pivetta, Leonardo Benedini, Paulo Marcos, Ma. Agustina Cócola, Mercedes Virginia Barros, Daniel Gregori, Leonardo Strazzere, Anderson Costa dos Santos, Mauro C. Geraldes","doi":"10.1007/s12583-023-1823-5","DOIUrl":"https://doi.org/10.1007/s12583-023-1823-5","url":null,"abstract":"Arroyo Verde epithermal deposit, in the North Patagonia region of Argentina, is located within the Lower Chon Aike volcanism and is developed between 192.6 ± 2.5 Ma (mineralization host rock) and 189.5 ± 2.6 Ma (overlying lava). Marifil volcanic complex is the host rock for these veins, veinlets and breccias. This particular small deposit has developed low to intermediate sulphidation characteristics, with gangue mineral textures associated with several ore minerals. Electron probe microanalysis determines electrum, silver minerals such as acanthite, and tetrahedrite, related Ag-Cu minerals like jalpaite, mckinstryite, stromeyerite, and base metals like chalcopyrite, sphalerite, galena and pyrite. Fluid inclusions in quartz of two out of five events indicate that these Low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity (3.4 wt.% to 6.7 wt.% NaCl Eq) magmatic-hydrothermal fluid at 225 to 310 °C. The fluid inclusion measurements that indicate boiling (Event 3) were plotted, and based on this data, we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 m. This particular character has not been previously recorded for other sectors of the eastern north Patagonian region.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"26 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139751000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Insight into the Origin of Iron Ore Based on Elemental Contents of Magnetite and Whole-Rock Geochemistry: A Case of the Bipindi Banded Iron Formations, Nyong Complex, SW Cameroon 基于磁铁矿元素含量和全岩地球化学的铁矿石起源洞察：喀麦隆西南部尼永复合体比平迪带铁地层的一个案例

IF 3.3 2区地球科学

Journal of Earth Science Pub Date : 2024-02-14 DOI: 10.1007/s12583-022-1622-4

Landry Soh Tamehe, Huan Li, Sylvestre Ganno, Zuxing Chen, Yanick Brice Lemdjou, Safiyanu Muhammad Elatikpo

{"title":"Insight into the Origin of Iron Ore Based on Elemental Contents of Magnetite and Whole-Rock Geochemistry: A Case of the Bipindi Banded Iron Formations, Nyong Complex, SW Cameroon","authors":"Landry Soh Tamehe, Huan Li, Sylvestre Ganno, Zuxing Chen, Yanick Brice Lemdjou, Safiyanu Muhammad Elatikpo","doi":"10.1007/s12583-022-1622-4","DOIUrl":"https://doi.org/10.1007/s12583-022-1622-4","url":null,"abstract":"The Bipindi iron ore district is located in the central section of the Nyong Complex at the northwestern margin of the Congo Craton in Southwest Cameroon. This iron district contains numerous iron mineralization hosted by the Mewongo, Bibole, Kouambo, and Zambi banded iron formations (BIFs). These BIFs contain magnetite as the main iron ore mineral associated with pyrite, and gangue minerals are quartz with minor chlorite and amphibole. The origin of iron ore from these BIFs was investigated using a combination of in-situ magnetite and whole-rock chemistry. The studied BIF ore samples have a narrow range of TFe between 30.90 wt.% and 43.20 wt.%, indicating a low-grade ore. The geochemical signatures of magnetite such as low contents of base metals (e.g., Cu, Co, V, and Zn) and low Co/Zn ratios < 0.85 indicate a hydrothermal origin. Combined with the geochemical features of these BIFs, e. g., high Fe/Ti and Fe/Al ratios (mean > 600 and > 75, respectively), we suggest that magnetite was derived from a mixture of seawater and ∼0.1% low-temperature hydrothermal fluids in an oxidizing environment. Collectively, low-temperature hydrothermal and later metamorphic fluids were necessary for the transformation of the protolith Nyong Complex BIFs to iron ore.","PeriodicalId":15607,"journal":{"name":"Journal of Earth Science","volume":"96 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0