Journal of Geochemical Exploration最新文献_第8页

Multi-stage magma emplacement in the western end of the Jinchuan NiCu sulfide deposit, NW China, and mineral exploration strategy based on exploration data 中国西北部金川硫化镍铜矿床西端多期岩浆喷发及基于勘探数据的矿产勘探战略

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-30 DOI: 10.1016/j.gexplo.2024.107615

Long-Jiao Li , Xian-Cheng Mao , Zhan-Kun Liu , Xin-Ming Duan , Yun-Qi Wang , Qi-Xing Ai , De-Xian Li

The western intrusion of the world-class Jinchuan NiCu sulfide deposit consists of fine-grained and coarse-grained binary lithofacies units. However, recent exploration has revealed two layers of net-textured sulfides in the fine-grained unit at the western end of the Jinchuan intrusion, adding complexity to the genesis of sulfide mineralization. We measured chalcophile elements and collected exploration data on Cu and Ni content to investigate their genesis and prospecting potential. The lower fine-grained subunits, comprising a layer of disseminated sulfides (DS-1) in the bottom and overlain by massive sulfide (MS) and olivine-sulfide cumulates (NTS-1), were overlain by the upper fine-grained subunits disseminated sulfides (DS-2) with a core of net-textured sulfides (NTS-2). The coarse-grained lherzolite with disseminated sulfides (DS-3) sharply cut through the upper subunit. All disseminated samples have Cu/Pd ratios (11,414–128,626) that exceed the mantle range. Additionally, the Pd/Ru ratios of DS-1 (1.26–13.2) are the lowest, followed by DS-2 (3.69–13.5), and highest in DS-3 (2.80–33.6). The exploration data indicate that the Ni and Cu contents and Cu/(Cu + Ni) ratios are significantly higher in DS-3 than in DS-2, while DS-1 shows more dispersed. The NTS-1 exhibits significant Ir and Ru depletion, with Cu/(Cu + Ni) decreasing with depth, eventually encountering Ir and Ru-riched MS. In addition, NTS-2 shows partially Ir depletion but Ru non-depletion, and Cu/(Cu + Ni) increases with depth. These signatures suggest that the lower and upper subunits, along with the coarse-grained unit, formed from platinum-group elements (PGE) in increasingly depleted magma, likely resulting from prior sulfide segregation before emplacement. Furthermore, the differences in Ir and Ru depletion and the variation in the Cu/(Cu + Ni) trend with depth between NTS-1 and NTS-2 were explained by the migration direction of fractional sulfide liquid during sulfide fractionation. We propose that the western end of the Jinchuan intrusion was formed by multi-stage magma emplacement. The strong correlation between exploration data (Ni, Cu, and Cu/(Cu + Ni)) and various sulfide mineralization layers suggests that delineating the spatial range of each sulfide mineralization could provide valuable information for deep mineral prospectivity mapping.

世界级金川硫化镍铜矿床的西部侵入体由细粒和粗粒二元岩性单元组成。然而，最近的勘探在金川侵入体西端的细粒单元中发现了两层净纹理硫化物，增加了硫化物成矿的复杂性。我们测量了亲铝元素并收集了铜和镍含量的勘探数据，以研究其成因和找矿潜力。下部细粒亚单元由底部的浸染状硫化物层（DS-1）和块状硫化物（MS）及橄榄石硫化物积层（NTS-1）组成，上部细粒亚单元为浸染状硫化物层（DS-2），核心为净纹理硫化物（NTS-2）。粗粒蛭石与浸染状硫化物（DS-3）尖锐地切割了上亚单元。所有浸染状样品的铜/钯比率（11,414-128,626）都超过了地幔范围。此外，DS-1（1.26-13.2）的钯/钌比值最低，DS-2（3.69-13.5）次之，DS-3（2.80-33.6）最高。勘探数据表明，DS-3 中的 Ni 和 Cu 含量以及 Cu/（Cu + Ni）比值明显高于 DS-2，而 DS-1 则更为分散。NTS-1表现出明显的Ir和Ru贫化，Cu/（Cu + Ni）随深度降低，最终遇到Ir和Ru富集的MS。此外，NTS-2 显示部分 Ir 贫化，但 Ru 未贫化，Cu/（Cu + Ni）随深度增加。这些特征表明，下亚单元和上亚单元以及粗粒度单元是在日益贫化的岩浆中由铂族元素（PGE）形成的，很可能是在成岩之前硫化物偏析造成的。此外，NTS-1和NTS-2之间Ir和Ru贫化程度的差异以及Cu/（Cu + Ni）随深度变化的趋势，可以用硫化物分馏过程中分馏硫化物液体的迁移方向来解释。我们认为金川侵入体西端是由多级岩浆喷发形成的。勘探数据（镍、铜和铜/（铜+镍））与各硫化物矿化层之间的强相关性表明，划分各硫化物矿化层的空间范围可为深部找矿制图提供有价值的信息。

{"title":"Multi-stage magma emplacement in the western end of the Jinchuan NiCu sulfide deposit, NW China, and mineral exploration strategy based on exploration data","authors":"Long-Jiao Li , Xian-Cheng Mao , Zhan-Kun Liu , Xin-Ming Duan , Yun-Qi Wang , Qi-Xing Ai , De-Xian Li","doi":"10.1016/j.gexplo.2024.107615","DOIUrl":"10.1016/j.gexplo.2024.107615","url":null,"abstract":"<div><div>The western intrusion of the world-class Jinchuan Ni<img>Cu sulfide deposit consists of fine-grained and coarse-grained binary lithofacies units. However, recent exploration has revealed two layers of net-textured sulfides in the fine-grained unit at the western end of the Jinchuan intrusion, adding complexity to the genesis of sulfide mineralization. We measured chalcophile elements and collected exploration data on Cu and Ni content to investigate their genesis and prospecting potential. The lower fine-grained subunits, comprising a layer of disseminated sulfides (DS-1) in the bottom and overlain by massive sulfide (MS) and olivine-sulfide cumulates (NTS-1), were overlain by the upper fine-grained subunits disseminated sulfides (DS-2) with a core of net-textured sulfides (NTS-2). The coarse-grained lherzolite with disseminated sulfides (DS-3) sharply cut through the upper subunit. All disseminated samples have Cu/Pd ratios (11,414–128,626) that exceed the mantle range. Additionally, the Pd/Ru ratios of DS-1 (1.26–13.2) are the lowest, followed by DS-2 (3.69–13.5), and highest in DS-3 (2.80–33.6). The exploration data indicate that the Ni and Cu contents and Cu/(Cu + Ni) ratios are significantly higher in DS-3 than in DS-2, while DS-1 shows more dispersed. The NTS-1 exhibits significant Ir and Ru depletion, with Cu/(Cu + Ni) decreasing with depth, eventually encountering Ir and Ru-riched MS. In addition, NTS-2 shows partially Ir depletion but Ru non-depletion, and Cu/(Cu + Ni) increases with depth. These signatures suggest that the lower and upper subunits, along with the coarse-grained unit, formed from platinum-group elements (PGE) in increasingly depleted magma, likely resulting from prior sulfide segregation before emplacement. Furthermore, the differences in Ir and Ru depletion and the variation in the Cu/(Cu + Ni) trend with depth between NTS-1 and NTS-2 were explained by the migration direction of fractional sulfide liquid during sulfide fractionation. We propose that the western end of the Jinchuan intrusion was formed by multi-stage magma emplacement. The strong correlation between exploration data (Ni, Cu, and Cu/(Cu + Ni)) and various sulfide mineralization layers suggests that delineating the spatial range of each sulfide mineralization could provide valuable information for deep mineral prospectivity mapping.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"268 ","pages":"Article 107615"},"PeriodicalIF":3.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664325","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

Indicator element selection and lithological mapping using deep learning methods in the Dahongliutan area, NW China 利用深度学习方法在中国西北部大红柳滩地区选择指示元素并绘制岩性图

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-30 DOI: 10.1016/j.gexplo.2024.107611

Li Chen, Nannan Zhang, Jinyu Chang, Shibin Liao, Jintao Tao, Hao Zhang, Siyuan Li

Rare metal resources are extensively used in the emerging energy field, making the security and sustainability of rare metal supply chains critical issues. Pegmatite-type rare metal deposits are a significant source of rare metal resources. Geochemistry is one of the most direct and effective methods of mineral exploration. In this study, whole-rock geochemical data from the Akesayi region, located in the Western Kunlun area of China, were used to identify the indicative elements of pegmatite automatically. Based on the stream sediment geochemical data, various deep learning models have been employed to achieve automatic lithological identification of the area. The results indicate that a novel interpretable model using SHapley Additive exPlanations (SHAP) and eXtreme Gradient Boosting (XGBoost) was employed to select indicative elements for the pegmatite in the Akesayi region, identifying Ta and Rb as key elements. The state-of-the-art application of deep-learning algorithms for lithological mapping has proven to be highly effective. Among the four approaches, the ensemble strategy integrating 1D convolutional neural networks, 2D3D convolutional neural networks, and dual-branch neural networks yields the best lithological mapping results. This approach resulted in a total classification accuracy of 90.422 %, an average accuracy of 90.502 %, a Kappa coefficient of 89.643 %, and a user accuracy of 65.530 % for the pegmatite lithological unit. These results demonstrate that the proposed model can provide robust technical support for the exploration of rare metal pegmatites in regions with challenging natural conditions and limited research.

稀有金属资源被广泛应用于新兴能源领域，因此稀有金属供应链的安全性和可持续性成为关键问题。伟晶岩型稀有金属矿床是稀有金属资源的重要来源。地球化学是最直接有效的矿产勘探方法之一。本研究利用中国西昆仑地区阿克萨依地区的全岩地球化学数据，自动识别伟晶岩的指示元素。基于流体沉积物地球化学数据，采用多种深度学习模型实现了该地区岩性的自动识别。结果表明，使用 SHapley Additive exPlanations（SHAP）和 eXtreme Gradient Boosting（XGBoost）建立的新型可解释模型可为阿克萨伊地区的伟晶岩选择指示元素，并确定 Ta 和 Rb 为关键元素。事实证明，将深度学习算法应用于岩性制图是非常有效的。在四种方法中，整合了一维卷积神经网络、二维三维卷积神经网络和双分支神经网络的集合策略产生了最佳的岩性绘图结果。该方法对伟晶岩岩性单元的总分类准确率为 90.422%，平均准确率为 90.502%，卡帕系数为 89.643%，用户准确率为 65.530%。这些结果表明，所提出的模型可以为自然条件恶劣、研究有限地区的稀有金属伟晶岩勘探提供强有力的技术支持。

{"title":"Indicator element selection and lithological mapping using deep learning methods in the Dahongliutan area, NW China","authors":"Li Chen, Nannan Zhang, Jinyu Chang, Shibin Liao, Jintao Tao, Hao Zhang, Siyuan Li","doi":"10.1016/j.gexplo.2024.107611","DOIUrl":"10.1016/j.gexplo.2024.107611","url":null,"abstract":"<div><div>Rare metal resources are extensively used in the emerging energy field, making the security and sustainability of rare metal supply chains critical issues. Pegmatite-type rare metal deposits are a significant source of rare metal resources. Geochemistry is one of the most direct and effective methods of mineral exploration. In this study, whole-rock geochemical data from the Akesayi region, located in the Western Kunlun area of China, were used to identify the indicative elements of pegmatite automatically. Based on the stream sediment geochemical data, various deep learning models have been employed to achieve automatic lithological identification of the area. The results indicate that a novel interpretable model using SHapley Additive exPlanations (SHAP) and eXtreme Gradient Boosting (XGBoost) was employed to select indicative elements for the pegmatite in the Akesayi region, identifying Ta and Rb as key elements. The state-of-the-art application of deep-learning algorithms for lithological mapping has proven to be highly effective. Among the four approaches, the ensemble strategy integrating 1D convolutional neural networks, 2D<img>3D convolutional neural networks, and dual-branch neural networks yields the best lithological mapping results. This approach resulted in a total classification accuracy of 90.422 %, an average accuracy of 90.502 %, a Kappa coefficient of 89.643 %, and a user accuracy of 65.530 % for the pegmatite lithological unit. These results demonstrate that the proposed model can provide robust technical support for the exploration of rare metal pegmatites in regions with challenging natural conditions and limited research.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"268 ","pages":"Article 107611"},"PeriodicalIF":3.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664305","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

Metallogenic model of the carboniferous karst bauxites in Central Guizhou Province, Southwest China 中国西南贵州省中部石炭系岩溶铝土矿的成矿模式

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-29 DOI: 10.1016/j.gexplo.2024.107607

Chaokun Luo, Ruidong Yang, Junbo Gao, Jun Chen, Hongcheng Mo

Karst bauxites, the dominant mineral resources of Guizhou Province, southwest China, are hosted in the Lower Carboniferous Jiujialu Formation and the Lower Permian Dazhuyuan Formation. Currently, the total bauxite resources in central Guizhou area (CGA) have exceeded 500 million tons. Herein, we present a detailed petrographic, mineralogical, and geochemical characterization of the Tanguanyao and Ganba bauxite deposits located in CGA, with a particular focus on the differences in mineral composition. The aim of this study is to discuss the genesis of major minerals, analyze the sedimentary environment of representative bauxite deposits, and further reveal the metallogenic model of the Jiujialu Formation. Mineralogically, the Tanguanyao bauxite is mainly composed of diaspore, chamosite, anatase, and pyrite, whereas the Ganba bauxite consists of diaspore, chamosite, anatase, boehmite, kaolinite, and illite. This is because the Tanguanyao and Ganba bauxite deposits are located in different paleo-elevation, and their mineral compositions are significantly different due to the fluctuation of groundwater level. Mineralogical evidence suggests that the diaspore in the Tanguanyao and Ganba bauxite deposits also includes supergene crystallization in addition to metamorphic processes. In terms of sedimentary environment, the Tanguanyao bauxite deposit belongs to the phreatic bauxite type characterized by a reducing environment, while the Ganba bauxite belongs to the transitional type between the vadose and phreatic facies.

岩溶铝土矿是中国西南部贵州省的主要矿产资源，赋存于下石炭统九家路地层和下二叠统大竹园地层中。目前，贵州中部地区铝土矿资源总量已超过 5 亿吨。在此，我们对位于黔中地区的唐古窑铝土矿和干坝铝土矿矿床进行了详细的岩石学、矿物学和地球化学特征描述，尤其关注了矿物成分的差异。本研究旨在探讨主要矿物的成因，分析具有代表性的铝土矿床的沉积环境，进一步揭示九家套地层的成矿模式。从矿物组成上看，唐古尧铝土矿主要由透辉石、闪长石、锐钛矿和黄铁矿组成，而甘坝铝土矿则由透辉石、闪长石、锐钛矿、波长石、高岭石和伊利石组成。这是因为唐古尧铝土矿和甘坝铝土矿矿床所处的古海拔高度不同，受地下水位波动的影响，其矿物组成也明显不同。矿物学证据表明，唐古尧铝土矿和甘坝铝土矿矿床的透辉作用除变质作用外，还包括超生结晶作用。在沉积环境方面，唐古尧铝土矿床属于以还原环境为特征的岩相铝土矿类型，而甘坝铝土矿则属于介于岩相和岩相之间的过渡型铝土矿类型。

{"title":"Metallogenic model of the carboniferous karst bauxites in Central Guizhou Province, Southwest China","authors":"Chaokun Luo, Ruidong Yang, Junbo Gao, Jun Chen, Hongcheng Mo","doi":"10.1016/j.gexplo.2024.107607","DOIUrl":"10.1016/j.gexplo.2024.107607","url":null,"abstract":"<div><div>Karst bauxites, the dominant mineral resources of Guizhou Province, southwest China, are hosted in the Lower Carboniferous Jiujialu Formation and the Lower Permian Dazhuyuan Formation. Currently, the total bauxite resources in central Guizhou area (CGA) have exceeded 500 million tons. Herein, we present a detailed petrographic, mineralogical, and geochemical characterization of the Tanguanyao and Ganba bauxite deposits located in CGA, with a particular focus on the differences in mineral composition. The aim of this study is to discuss the genesis of major minerals, analyze the sedimentary environment of representative bauxite deposits, and further reveal the metallogenic model of the Jiujialu Formation. Mineralogically, the Tanguanyao bauxite is mainly composed of diaspore, chamosite, anatase, and pyrite, whereas the Ganba bauxite consists of diaspore, chamosite, anatase, boehmite, kaolinite, and illite. This is because the Tanguanyao and Ganba bauxite deposits are located in different paleo-elevation, and their mineral compositions are significantly different due to the fluctuation of groundwater level. Mineralogical evidence suggests that the diaspore in the Tanguanyao and Ganba bauxite deposits also includes supergene crystallization in addition to metamorphic processes. In terms of sedimentary environment, the Tanguanyao bauxite deposit belongs to the phreatic bauxite type characterized by a reducing environment, while the Ganba bauxite belongs to the transitional type between the vadose and phreatic facies.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"268 ","pages":"Article 107607"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664324","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

GEMAS: Boron as a geochemical proxy for weathering of European agricultural soil GEMAS：硼作为欧洲农业土壤风化的地球化学替代物

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-29 DOI: 10.1016/j.gexplo.2024.107618

Philippe Négrel , Anna Ladenberger , Alecos Demetriades , Clemens Reimann , Manfred Birke , Martiya Sadeghi , The GEMAS Project Team

About a century ago, B was recognised as an essential element for the normal growth of plants and terrestrial organisms. Limitations for plant development have been recognised in agricultural systems, particularly in highly weathered soil. Boron is rarely analysed in whole rock or soil analysis, as it requires specific analytical techniques. It is often determined, after partial extraction (aqua regia or CaCl), usually on a limited number of samples. Many more questions than answers exist about the environmental behaviour of B.

We present B contents in agricultural soil samples (0–10 cm) collected in 33 European countries (5.6 million km²) during the GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) continental-scale project. The B content, determined by ICP-MS following hot aqua regia extraction, varies in European agricultural soil from 0.5 to 49 mg/kg (median 2.42 mg/kg, n = 2108), which is somewhat similar to total B estimates for the Upper Continental Crust (17–47 mg/kg). Its spatial distribution in agricultural soil shows a patchy pattern with low values in regions with granitic bedrock and high contents in soil formed over limestone and in volcanic areas.

Boron geochemical behaviour in soil is strongly dependent on other factors such as pH, CEC, presence of organic matter, clay and secondary oxides and hydroxides. Boron geochemical mapping at the continental scale in arable soil allows investigations of plant health, i.e., the beneficial and adverse effects due to the nutritional status of boron.

大约一个世纪前，人们就认识到硼是植物和陆地生物正常生长所必需的元素。在农业系统中，尤其是在高度风化的土壤中，植物的生长受到了限制。由于硼需要特殊的分析技术，因此很少对整个岩石或土壤进行分析。通常是在部分萃取（王水或 CaCl）后，对数量有限的样本进行测定。我们介绍了在 GEMAS（农业和牧场土壤地球化学绘图）大陆尺度项目中收集的 33 个欧洲国家（560 万平方公里）的农业土壤样本（0-10 厘米）中的硼含量。欧洲农业土壤中的硼含量是在热王水提取后通过 ICP-MS 测定的，从 0.5 毫克/千克到 49 毫克/千克不等（中位数为 2.42 毫克/千克，n = 2108），这与上大陆结壳的硼总估计值（17-47 毫克/千克）有些相似。硼在农业土壤中的空间分布呈现斑块状，在花岗岩基岩地区含量较低，而在石灰岩和火山地区形成的土壤中含量较高。硼在土壤中的地球化学行为在很大程度上取决于其他因素，如 pH 值、CEC、有机物的存在、粘土以及次生氧化物和氢氧化物。在大陆范围内绘制耕地土壤中的硼地球化学图，可以调查植物的健康状况，即硼的营养状况对植物的有利和不利影响。

{"title":"GEMAS: Boron as a geochemical proxy for weathering of European agricultural soil","authors":"Philippe Négrel , Anna Ladenberger , Alecos Demetriades , Clemens Reimann , Manfred Birke , Martiya Sadeghi , The GEMAS Project Team","doi":"10.1016/j.gexplo.2024.107618","DOIUrl":"10.1016/j.gexplo.2024.107618","url":null,"abstract":"<div><div>About a century ago, B was recognised as an essential element for the normal growth of plants and terrestrial organisms. Limitations for plant development have been recognised in agricultural systems, particularly in highly weathered soil. Boron is rarely analysed in whole rock or soil analysis, as it requires specific analytical techniques. It is often determined, after partial extraction (aqua regia or Ca<img>Cl), usually on a limited number of samples. Many more questions than answers exist about the environmental behaviour of B.</div><div>We present B contents in agricultural soil samples (0–10 cm) collected in 33 European countries (5.6 million km<sup>2</sup>) during the GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) continental-scale project. The B content, determined by ICP-MS following hot aqua regia extraction, varies in European agricultural soil from 0.5 to 49 mg/kg (median 2.42 mg/kg, <em>n</em> = 2108), which is somewhat similar to total B estimates for the Upper Continental Crust (17–47 mg/kg). Its spatial distribution in agricultural soil shows a patchy pattern with low values in regions with granitic bedrock and high contents in soil formed over limestone and in volcanic areas.</div><div>Boron geochemical behaviour in soil is strongly dependent on other factors such as pH, CEC, presence of organic matter, clay and secondary oxides and hydroxides. Boron geochemical mapping at the continental scale in arable soil allows investigations of plant health, i.e., the beneficial and adverse effects due to the nutritional status of boron.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107618"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579039","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 geochemistry and zircon U-Pb geochronology of mafic sills from the Karagwe Ankolean Belt of northwestern Tanzania: Implications for petrogenesis and Ni-Cu-Co prospectivity 坦桑尼亚西北部 Karagwe Ankolean 矿带岩浆岩的微量元素地球化学和锆石 U-Pb 地质年代：对成岩学和镍铜钴勘探的影响

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-29 DOI: 10.1016/j.gexplo.2024.107614

Gerald L. Chuwa , Charles H. Kasanzu , Emmanuel O. Kazimoto , Francisco E. Apen

In northwestern Tanzania, mafic sills intruded the Akanyaru and Kagera Supergroup rocks in the Mesoproterozoic Karagwe-Ankolean Belt (KAB). Trace element geochemistry and UPb geochronology results are reported to unravel petrogenetic and geochronological evolution of the sills in order to place constraints on Ni-Cu-Co prospectivity of the KAB. The sills are subalkaline gabbronorite and dolerite. They are relatively evolved Mg# = 43–69, with transitional metal contents lower than juvenile mafic-ultramafic rocks of the Kabanga-Musongati Alignment (KMA) intrusions. The sills can be subdivided into western and eastern swarms that display similar geochemical characteristics, including enrichment in LREE (Light Rare Earth Elements), LILE (Large Ion Lithophile Elements), Pb, Th, and U relative to HFSE (High Field Strength Elements). They are characterised by depletions of Nb-Ta-Ti in primitive mantle normalised spiderplots, enrichments in LREE and relatively flat MREE and HREE with negative Eu anomalies Eu/Eu* = 0.74–0.94 in chondrite normalised REE spiderplots. Together with elemental trace element ratios Nb/Yb, Th/Yb, Zr/Nb, Ba/Nb, and Nb-Yb-Ti index suggest derivation of the mafic sills from a sub-continental lithospheric mantle source followed by fractional crystallisation and crustal contamination.

Zircon UPb geochronology yields a concordant weighted age of 1424 ± 13 Ma for a gabbronorite in the western sills and an upper age intercept of 1411 ± 54 Ma for a dolerite in the eastern sills. The emplacement ages are similar to those of the KMA and the Lake Victoria Dolerite Dyke Swarm (LVDDS). Temporal and geochemical similarities with the KMA and LVDDS supports for emplacement of the mafic sills in an intracratonic rift setting. Although the KAB sills are relatively more geochemically evolved, they share similar evolutionary path with Ni-Cu-Co mineralised juvenile KMA intrusions, sensu stricto interaction with sulphur bearing country rocks. We suggest that trace elements geochemistry including chalcophile elemental ratios (Ni/Cr and Cu/Zn) of the sills be applied as vectors to locate prospective Ni-Cu-Co targets in the KAB.

在坦桑尼亚西北部，中生代卡拉格韦-安科伦带（KAB）的阿卡尼亚鲁和卡盖拉超群岩侵入了岩浆岩。报告了痕量元素地球化学和 UPb 地质年代学的结果，以揭示这些山体的岩石成因和地质年代演变，从而对 KAB 的镍铜钴矿床的远景提出限制。闪长岩为亚碱性辉长岩和辉绿岩。它们是相对演化的 Mg# = 43-69，过渡金属含量低于卡班加-穆松加提排列（KMA）侵入体的幼年黑云母-超黑云母岩。这些岩浆可细分为西部和东部岩群，它们显示出类似的地球化学特征，包括相对于 HFSE（高场强元素）富集的 LREE（轻稀土元素）、LILE（大离子亲岩元素）、Pb、Th 和 U。它们的特征是：在原始地幔归一化蛛状图中，Nb-Ta-Ti 元素减少；在软玉岩归一化 REE 蛛状图中，LREE 元素富集，MREE 和 HREE 元素相对平缓，Eu/Eu* = 0.74-0.94 为负 Eu 异常。这些元素与痕量元素比Nb/Yb、Th/Yb、Zr/Nb、Ba/Nb和Nb-Yb-Ti指数一起表明，岩浆岩来自次大陆岩石圈地幔源，随后经过碎裂结晶和地壳污染。锆石UPb地质年代测定结果显示，西部山体中的榴辉岩的加权年龄为1424 ± 13 Ma，东部山体中的辉长岩的上年龄截距为1411 ± 54 Ma。这些成岩年龄与 KMA 和维多利亚湖辉绿岩堤群（LVDDS）的成岩年龄相似。与 KMA 和 LVDDS 在时间和地球化学方面的相似性支持了岩浆岩在地壳内部裂谷环境中的形成。虽然KAB岩体的地球化学演化程度相对较高，但它们与KMA侵入体中的镍铜钴矿化幼体有着相似的演化路径，即与含硫乡土岩的严格互动。我们建议将痕量元素地球化学，包括磨屑的亲铝元素比率（镍/铬和铜/锌），作为矢量来定位 KAB 的潜在镍铜钴目标。

{"title":"Trace element geochemistry and zircon U-Pb geochronology of mafic sills from the Karagwe Ankolean Belt of northwestern Tanzania: Implications for petrogenesis and Ni-Cu-Co prospectivity","authors":"Gerald L. Chuwa , Charles H. Kasanzu , Emmanuel O. Kazimoto , Francisco E. Apen","doi":"10.1016/j.gexplo.2024.107614","DOIUrl":"10.1016/j.gexplo.2024.107614","url":null,"abstract":"<div><div>In northwestern Tanzania, mafic sills intruded the Akanyaru and Kagera Supergroup rocks in the Mesoproterozoic Karagwe-Ankolean Belt (KAB). Trace element geochemistry and U<img>Pb geochronology results are reported to unravel petrogenetic and geochronological evolution of the sills in order to place constraints on Ni-Cu-Co prospectivity of the KAB. The sills are subalkaline gabbronorite and dolerite. They are relatively evolved Mg# = 43–69, with transitional metal contents lower than juvenile mafic-ultramafic rocks of the Kabanga-Musongati Alignment (KMA) intrusions. The sills can be subdivided into western and eastern swarms that display similar geochemical characteristics, including enrichment in LREE (Light Rare Earth Elements), LILE (Large Ion Lithophile Elements), Pb, Th, and U relative to HFSE (High Field Strength Elements). They are characterised by depletions of Nb-Ta-Ti in primitive mantle normalised spiderplots, enrichments in LREE and relatively flat MREE and HREE with negative Eu anomalies Eu/Eu* = 0.74–0.94 in chondrite normalised REE spiderplots. Together with elemental trace element ratios Nb/Yb, Th/Yb, Zr/Nb, Ba/Nb, and Nb-Yb-Ti index suggest derivation of the mafic sills from a sub-continental lithospheric mantle source followed by fractional crystallisation and crustal contamination.</div><div>Zircon U<img>Pb geochronology yields a concordant weighted age of 1424 ± 13 Ma for a gabbronorite in the western sills and an upper age intercept of 1411 ± 54 Ma for a dolerite in the eastern sills. The emplacement ages are similar to those of the KMA and the Lake Victoria Dolerite Dyke Swarm (LVDDS). Temporal and geochemical similarities with the KMA and LVDDS supports for emplacement of the mafic sills in an intracratonic rift setting. Although the KAB sills are relatively more geochemically evolved, they share similar evolutionary path with Ni-Cu-Co mineralised juvenile KMA intrusions, sensu stricto interaction with sulphur bearing country rocks. We suggest that trace elements geochemistry including chalcophile elemental ratios (Ni/Cr and Cu/Zn) of the sills be applied as vectors to locate prospective Ni-Cu-Co targets in the KAB.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"268 ","pages":"Article 107614"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664309","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

REE-bearing phosphate mineral chemistry for iron sulfide‑copper‑gold exploration: A study at Jericho, NW Queensland, Australia 含 REE 的磷酸盐矿物化学用于硫化铁-铜-金勘探：澳大利亚昆士兰西北部杰里科研究

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-29 DOI: 10.1016/j.gexplo.2024.107608

Travis Batch , Caroline Tiddy , Adrienne Brotodewo , David Giles , Glen Little , Antonio Belperio , Michael Taylor , Vaclav Metelka

We present mineral chemistry data from the rare-earth element (REE) bearing phosphates monazite and rhabdophane sampled from the Jericho iron sulfide‑copper‑gold (ISCG) deposit in the Cloncurry District, north-west Queensland. REE-bearing phosphates sampled from within the narrow mineralised sequence have a characteristic mineralogy and chemical signature compared to REE-bearing phosphates sampled from the unmineralised metamorphic host sequences only meters away. The mineralised samples contain the hydrated REE-bearing phosphate rhabdophane (REEPO₄ · n H₂O) which occurs as veins and ‘spongy’ textured grains in association with sulfide minerals and commonly replacing apatite. In contrast, the metamorphic host rocks contain monazite (REEPO₄) with metamorphic textures and are rarely associated with sulfide minerals. Rhabdophane and monazite have comparable ΣREE and REE profiles, however the rhabdophane grains are characterised by lower Th contents and higher Ca, S and water contents. Molar ratios of S/Th and Ca/Th, determined by electron probe microanalyser (EPMA), can be used to discriminate between REE phosphates from within the Jericho mineralisation from those not associated with mineralisation. The presence of hydrated rhabdophane also indicates the temperature of mineralisation is at or below 200–250 °C.

我们介绍了从昆士兰州西北部克隆库里区杰里科硫化铁-铜-金（ISCG）矿床采样的含稀土元素（REE）磷酸盐独居石和菱锰矿的矿物化学数据。在狭窄的成矿序列中取样的含 REE 磷酸盐与在数米之外未成矿的变质母岩序列中取样的含 REE 磷酸盐相比，具有独特的矿物学和化学特征。矿化样本中含有水合含 REE 磷酸盐的磷酸盐 rhabdophane（REEPO4 - n H2O），它以矿脉和 "海绵状 "纹理颗粒的形式出现，与硫化物矿物伴生，通常取代磷灰石。相比之下，变质主岩中的独居石（REEPO4）具有变质质地，很少与硫化物矿物伴生。斜长石和独居石具有相似的 ΣREE 和 REE 图谱，但斜长石晶粒的特征是 Th 含量较低，而 Ca、S 和水含量较高。通过电子探针显微分析仪（EPMA）测定的S/Th和Ca/Th摩尔比可用于区分杰里科矿化区内的REE磷酸盐和与矿化无关的磷酸盐。水合菱锰矿的存在也表明矿化温度在 200-250 ℃ 或以下。

{"title":"REE-bearing phosphate mineral chemistry for iron sulfide‑copper‑gold exploration: A study at Jericho, NW Queensland, Australia","authors":"Travis Batch , Caroline Tiddy , Adrienne Brotodewo , David Giles , Glen Little , Antonio Belperio , Michael Taylor , Vaclav Metelka","doi":"10.1016/j.gexplo.2024.107608","DOIUrl":"10.1016/j.gexplo.2024.107608","url":null,"abstract":"<div><div>We present mineral chemistry data from the rare-earth element (REE) bearing phosphates monazite and rhabdophane sampled from the Jericho iron sulfide‑copper‑gold (ISCG) deposit in the Cloncurry District, north-west Queensland. REE-bearing phosphates sampled from within the narrow mineralised sequence have a characteristic mineralogy and chemical signature compared to REE-bearing phosphates sampled from the unmineralised metamorphic host sequences only meters away. The mineralised samples contain the hydrated REE-bearing phosphate rhabdophane (REEPO<sub>4</sub> · n H<sub>2</sub>O) which occurs as veins and ‘spongy’ textured grains in association with sulfide minerals and commonly replacing apatite. In contrast, the metamorphic host rocks contain monazite (REEPO<sub>4</sub>) with metamorphic textures and are rarely associated with sulfide minerals. Rhabdophane and monazite have comparable ΣREE and REE profiles, however the rhabdophane grains are characterised by lower Th contents and higher Ca, S and water contents. Molar ratios of S/Th and Ca/Th, determined by electron probe microanalyser (EPMA), can be used to discriminate between REE phosphates from within the Jericho mineralisation from those not associated with mineralisation. The presence of hydrated rhabdophane also indicates the temperature of mineralisation is at or below 200–250 °C.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107608"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molybdenite Re-Os geochronology and conditions of formation of potassic and sodic-calcic alteration associated with the Plaka porphyry Mo-Cu system, Lavrion, Greece

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-29 DOI: 10.1016/j.gexplo.2024.107609

Panagiotis Voudouris , Vasilios Melfos , Margarita Melfou , Alexandre Tarantola , Max Frenzel , Paul G. Spry , Konstantinos Soukis , Christophe Scheffer , Olivier Vanderhaeghe , Laurie Reisberg , Lambrini Papadopoulou , Christina Stouraiti , Constantinos Mavrogonatos

The Plaka porphyry Mo-Cu system occurs in the world-class Lavrion Ag-Pb-Zn district in Attica, southern Greece. It is spatially associated with a granodiorite porphyry that intruded the Attic-Cycladic Crystalline Complex in the late Miocene, along the footwall of the Western Cycladic detachment fault. A Re-Os age of 9.51 ± 0.04 Ma indicates that molybdenite formed during the early stage of the granodiorite porphyry intrusion and that subsequent cooling was very rapid. Brittle deformation and hydrothermal fluid flow created a network of A-, B-, diopside-actinolite and D-veins, associated with potassic-, sodic-calcic and sericitic alterations. Potassic alteration is characterized by secondary biotite + K-feldspar + quartz + magnetite ± apatite, contains disseminated molybdenite, pyrite, and chalcopyrite, and formed at 420–500 °C, at pressures up to 530 bars (< 5.3 km depth) from hydrothermal fluids that underwent phase separation. Sodic-calcic alteration is devoid of Cu-Mo mineralization and, consists of diopside + actinolite + oligoclase/andesine + titanite + magnetite ± epidote-allanite ± chlorite ± quartz, which corresponded to a temperature range of between 350 and < 500 °C. Primary magnetite, titanite and biotite crystallized between the nickel‑nickel oxide (NNO) and hematite-magnetite (HM) buffers, indicating fairly oxidizing conditions for the granodioritic magma. Hydrothermal biotite plots closer to the HM buffer suggesting increasing oxygen fugacity during exsolution of the hydrothermal fluids associated with potassic alteration. The system evolved toward more reducing conditions during sericitic alteration and associated pyrite-molybdenite mineralization. A combination of evaporated seawater and magmatic fluids likely caused formation of the sodic-calcic alteration through the decarbonation of the host marble.

{"title":"Molybdenite Re-Os geochronology and conditions of formation of potassic and sodic-calcic alteration associated with the Plaka porphyry Mo-Cu system, Lavrion, Greece","authors":"Panagiotis Voudouris , Vasilios Melfos , Margarita Melfou , Alexandre Tarantola , Max Frenzel , Paul G. Spry , Konstantinos Soukis , Christophe Scheffer , Olivier Vanderhaeghe , Laurie Reisberg , Lambrini Papadopoulou , Christina Stouraiti , Constantinos Mavrogonatos","doi":"10.1016/j.gexplo.2024.107609","DOIUrl":"10.1016/j.gexplo.2024.107609","url":null,"abstract":"<div><div>The Plaka porphyry Mo-Cu system occurs in the world-class Lavrion Ag-Pb-Zn district in Attica, southern Greece. It is spatially associated with a granodiorite porphyry that intruded the Attic-Cycladic Crystalline Complex in the late Miocene, along the footwall of the Western Cycladic detachment fault. A Re-Os age of 9.51 ± 0.04 Ma indicates that molybdenite formed during the early stage of the granodiorite porphyry intrusion and that subsequent cooling was very rapid. Brittle deformation and hydrothermal fluid flow created a network of A-, B-, diopside-actinolite and D-veins, associated with potassic-, sodic-calcic and sericitic alterations. Potassic alteration is characterized by secondary biotite + K-feldspar + quartz + magnetite ± apatite, contains disseminated molybdenite, pyrite, and chalcopyrite, and formed at 420–500 °C, at pressures up to 530 bars (< 5.3 km depth) from hydrothermal fluids that underwent phase separation. Sodic-calcic alteration is devoid of Cu-Mo mineralization and, consists of diopside + actinolite + oligoclase/andesine + titanite + magnetite ± epidote-allanite ± chlorite ± quartz, which corresponded to a temperature range of between 350 and < 500 °C. Primary magnetite, titanite and biotite crystallized between the nickel‑nickel oxide (NNO) and hematite-magnetite (HM) buffers, indicating fairly oxidizing conditions for the granodioritic magma. Hydrothermal biotite plots closer to the HM buffer suggesting increasing oxygen fugacity during exsolution of the hydrothermal fluids associated with potassic alteration. The system evolved toward more reducing conditions during sericitic alteration and associated pyrite-molybdenite mineralization. A combination of evaporated seawater and magmatic fluids likely caused formation of the sodic-calcic alteration through the decarbonation of the host marble.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"270 ","pages":"Article 107609"},"PeriodicalIF":3.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164550","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

Assessment of potentially toxic elements in some wild edible plants of district Doda, Jammu and Kashmir, India 印度查谟和克什米尔多达地区一些野生食用植物中潜在有毒元素的评估

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-28 DOI: 10.1016/j.gexplo.2024.107604

Sania Hamid , Devendra Kumar Pandey , Deepika Singh

Wild edible plants have played a crucial role since ages, in sustaining the local communities across globe, particularly during food scarcity, by supplementing the household diets. Despite their significance, the nutritional composition of wild edible plants has been inadequately researched and generally poorly understood. Moreover the studies of nutritional contents usually overlook the presence of potentially toxic elements(PTEs) which may be detrimental to the human health. This study was aimed at assessing the levels of PTEs (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn), in selected wild edible plants traditionally consumed by rural people of District Doda. For this purpose the leaves of three wild edible plants, namely Taraxacum officinale, Urtica dioica and Phytolacca acinosa were collected, air-dried and processed into powder. The plant samples were analyzed using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The findings of this study exhibited that PTEs were detectable in all the three tested wild edible plants. The levels of PTEs (mg/1000gdw) were found to be Cu (18.1 to 36.1), Fe (646.6 to 1457.8), Mn (80.4 to 207.6), Se (0.1 to 0.3) and Zn (58.2 to 86.8), PTEs Al, As, Ba, Cd, Co, Cr, Hg, Ni, Pb, and Sr were also detectable in all the three analyzed plant samples. The Al content was found to be highest among these PTEs (427.7 to 1224.4 mg/ 1000 g dw) which can pose health risks.

自古以来，野生食用植物在维持全球各地当地社区的生计方面发挥着至关重要的作用，尤其是在食物匮乏的情况下，可以补充家庭饮食。尽管野生食用植物具有重要意义，但人们对其营养成分的研究一直不足，普遍了解甚少。此外，对营养成分的研究通常会忽略可能对人体健康有害的潜在有毒元素（PTEs）的存在。本研究旨在评估多达地区农村居民传统食用的部分野生植物中的潜在有毒元素（铝、砷、钡、镉、钴、铬、铜、铁、汞、锰、镍、铅、硒、锶和锌）含量。为此，研究人员采集了三种野生食用植物的叶子，即 Taraxacum officinale、Urtica dioica 和 Phytolacca acinosa，将其风干并加工成粉末。使用电感耦合等离子体质谱仪（ICP-MS）对植物样本进行了分析。研究结果表明，在所有三种受测野生食用植物中都能检测到 PTEs。PTEs 的含量（毫克/1000 克重）分别为铜（18.1 至 36.1）、铁（646.6 至 1457.8）、锰（80.4 至 207.6）、硒（0.1 至 0.3）和锌（58.2 至 86.8），在所有三种分析过的植物样本中还检测到了 PTEs Al、As、Ba、Cd、Co、Cr、Hg、Ni、Pb 和 Sr。在这些 PTE 中，铝的含量最高（427.7 至 1224.4 毫克/1000 克干重），会对健康造成危害。

{"title":"Assessment of potentially toxic elements in some wild edible plants of district Doda, Jammu and Kashmir, India","authors":"Sania Hamid , Devendra Kumar Pandey , Deepika Singh","doi":"10.1016/j.gexplo.2024.107604","DOIUrl":"10.1016/j.gexplo.2024.107604","url":null,"abstract":"<div><div>Wild edible plants have played a crucial role since ages, in sustaining the local communities across globe, particularly during food scarcity, by supplementing the household diets. Despite their significance, the nutritional composition of wild edible plants has been inadequately researched and generally poorly understood. Moreover the studies of nutritional contents usually overlook the presence of potentially toxic elements(PTEs) which may be detrimental to the human health. This study was aimed at assessing the levels of PTEs (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn), in selected wild edible plants traditionally consumed by rural people of District Doda. For this purpose the leaves of three wild edible plants, namely <em>Taraxacum officinale, Urtica dioica</em> and <em>Phytolacca acinosa</em> were collected, air-dried and processed into powder. The plant samples were analyzed using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The findings of this study exhibited that PTEs were detectable in all the three tested wild edible plants. The levels of PTEs (mg/1000gdw) were found to be Cu (18.1 to 36.1), Fe (646.6 to 1457.8), Mn (80.4 to 207.6), Se (0.1 to 0.3) and Zn (58.2 to 86.8), PTEs Al, As, Ba, Cd, Co, Cr, Hg, Ni, Pb, and Sr were also detectable in all the three analyzed plant samples. The Al content was found to be highest among these PTEs (427.7 to 1224.4 mg/ 1000 g dw) which can pose health risks.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107604"},"PeriodicalIF":3.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554135","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

Distribution, enrichment characteristics and prospecting potential of lithium in Uzbekistan: Insights from 1:1 million geochemical mapping 乌兹别克斯坦锂的分布、富集特征和勘探潜力：1:100 万地球化学绘图的启示

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-28 DOI: 10.1016/j.gexplo.2024.107606

Jifei Cao , Wenyuan Li , Maksud Isokov , Jakhongir Movlanov , Miraziz Mirkhamdamov , Zhongping Ma , Kai Weng , Kai Cao , Guanglu Meng

With the world economy gradually shifting to alow‑carbon and greener model in recent years, there is a growing need for developing key metals like lithium in economic development. Economic growth has sped up the country's shift to a green economy along with Uzbekistan's reform and opening up, and the country's developing major mineral resources, such as lithium, have garnered a lot of attention. Owing to lithium resource protential of Uzbekistan is unclear, it is important to examine the possibility of lithium mineralization. The distribution and enrichment characteristics of lithium in the Uzbeksitan Tianshan are studied in this paper, based on geochemical mapping data at a 1:1000000 scale. It's concluded that stream sediments from the Tianshan region of Uzbekistan have higher concentration of lithium than the continental crust, and the South Tianshan has the highest lithium content. Lithium mineralization has been found in the lithium-geochemical anomaly areas in the eastern part of Uzbekistan South Tianshan through field investigation. Spodumene pegmatite, the first instance of pegmatitic type lithium mineralization in this region and even in the Tianshan orogenic belt of Central Asia. In conjunction with the geological background analysis, the metallogenic potential of lithium was assessed, resulting in the identification of four regions with lithium geochemical anomaly, and these sites will serve as target areas for Li deposits prospecting work in the future. This work has significant implications for the advancement of our understanding of the metallogenic theory of pegmatite-type Li deposits, as well as practical guiding significance for lithium ore prospecting in the Tianshan orogenic belt of Central Asia.

近年来，随着世界经济逐渐向低碳、绿色模式转变，经济发展对开发锂等关键金属的需求日益增长。随着乌兹别克斯坦的改革开放，经济增长加速了该国向绿色经济的转变，该国开发锂等主要矿产资源的工作也备受关注。由于乌兹别克斯坦的锂资源潜力尚不明确，因此研究锂矿化的可能性非常重要。本文基于 1:1000000 比例尺的地球化学绘图数据，研究了乌兹别克天山锂的分布和富集特征。结论是乌兹别克斯坦天山地区的溪流沉积物中锂的含量高于大陆地壳，其中南天山的锂含量最高。通过实地考察，在乌兹别克斯坦南天山东部的锂地球化学异常区发现了锂矿化。该地区乃至中亚天山造山带首次发现伟晶岩型锂矿化。结合地质背景分析，对锂的成矿潜力进行了评估，确定了四个锂地球化学异常区域，这些地点将作为未来锂矿床勘探工作的目标区域。这项工作对推进我们对伟晶岩型锂矿床成矿理论的认识具有重要意义，对中亚天山造山带锂矿找矿也具有实际指导意义。

{"title":"Distribution, enrichment characteristics and prospecting potential of lithium in Uzbekistan: Insights from 1:1 million geochemical mapping","authors":"Jifei Cao , Wenyuan Li , Maksud Isokov , Jakhongir Movlanov , Miraziz Mirkhamdamov , Zhongping Ma , Kai Weng , Kai Cao , Guanglu Meng","doi":"10.1016/j.gexplo.2024.107606","DOIUrl":"10.1016/j.gexplo.2024.107606","url":null,"abstract":"<div><div>With the world economy gradually shifting to alow‑carbon and greener model in recent years, there is a growing need for developing key metals like lithium in economic development. Economic growth has sped up the country's shift to a green economy along with Uzbekistan's reform and opening up, and the country's developing major mineral resources, such as lithium, have garnered a lot of attention. Owing to lithium resource protential of Uzbekistan is unclear, it is important to examine the possibility of lithium mineralization. The distribution and enrichment characteristics of lithium in the Uzbeksitan Tianshan are studied in this paper, based on geochemical mapping data at a 1:1000000 scale. It's concluded that stream sediments from the Tianshan region of Uzbekistan have higher concentration of lithium than the continental crust, and the South Tianshan has the highest lithium content. Lithium mineralization has been found in the lithium-geochemical anomaly areas in the eastern part of Uzbekistan South Tianshan through field investigation. Spodumene pegmatite, the first instance of pegmatitic type lithium mineralization in this region and even in the Tianshan orogenic belt of Central Asia. In conjunction with the geological background analysis, the metallogenic potential of lithium was assessed, resulting in the identification of four regions with lithium geochemical anomaly, and these sites will serve as target areas for Li deposits prospecting work in the future. This work has significant implications for the advancement of our understanding of the metallogenic theory of pegmatite-type Li deposits, as well as practical guiding significance for lithium ore prospecting in the Tianshan orogenic belt of Central Asia.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"268 ","pages":"Article 107606"},"PeriodicalIF":3.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664312","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

Corrigendum to “Apatite-rich zones in the Uppermost Upper Zone, Northern Limb, Bushveld Complex: Possible non-conventional source of REE and TiO2” [J. Geochem. Explor. (2024) [107498] [263C]] 对 "布什维尔德复合体北缘最上层富磷灰石区：Possible non-conventional source of REE and TiO2" [J. Geochem.Geochem.Explor.(2024) [107498] [263C]]

IF 3.4 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2024-10-21 DOI: 10.1016/j.gexplo.2024.107589

Hakundwi Mandende , Themba Mothupi

引用次数: 0