The pervasive issue of food and nutrition security demands urgent attention on a global scale. This challenge affects diverse populations worldwide and is compounded by multifaceted factors. Achieving sustainable food and nutrition security for smallholders and communities necessitates a comprehensive, interdisciplinary strategy, urging collaboration among experts from various fields. Addressing this complex issue requires innovative, unconventional approaches to surmount existing challenges. Challenges such as insufficient resources, inadequate infrastructure, and limited market accesses are formidable barriers that must be dismantled for effective progress. To overcome these hurdles, it is imperative to identify existing building blocks across diverse sectors. Leveraging these building blocks can pave the way for an incremental progress strategy, steering us towards a holistic systems vision. An incremental approach allows for the integration of diverse components within the food and nutrition system. By identifying synergies and interrelated, systems-oriented strategies can enhance the resilience and efficiency of the entire food and nutrition ecosystem. A holistic and integrated perspective addresses the root causes of these issues, offering a path towards a more sustainable and equitable food system. Embracing such an approach is crucial in shaping a resilient future, safeguarding global communities against the persistent challenges of food and nutrition insecurity.
{"title":"The science of food safety and their health impacts","authors":"Amit Kumar , Vinod Kumar , Danijela Arsenov , Monika Thakur , Ashok Kumar , Ashish Khokhar , Chandra Shekhar Seth , Rupesh Kumar","doi":"10.1016/j.gexplo.2024.107596","DOIUrl":"10.1016/j.gexplo.2024.107596","url":null,"abstract":"<div><div>The pervasive issue of food and nutrition security demands urgent attention on a global scale. This challenge affects diverse populations worldwide and is compounded by multifaceted factors. Achieving sustainable food and nutrition security for smallholders and communities necessitates a comprehensive, interdisciplinary strategy, urging collaboration among experts from various fields. Addressing this complex issue requires innovative, unconventional approaches to surmount existing challenges. Challenges such as insufficient resources, inadequate infrastructure, and limited market accesses are formidable barriers that must be dismantled for effective progress. To overcome these hurdles, it is imperative to identify existing building blocks across diverse sectors. Leveraging these building blocks can pave the way for an incremental progress strategy, steering us towards a holistic systems vision. An incremental approach allows for the integration of diverse components within the food and nutrition system. By identifying synergies and interrelated, systems-oriented strategies can enhance the resilience and efficiency of the entire food and nutrition ecosystem. A holistic and integrated perspective addresses the root causes of these issues, offering a path towards a more sustainable and equitable food system. Embracing such an approach is crucial in shaping a resilient future, safeguarding global communities against the persistent challenges of food and nutrition insecurity.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107596"},"PeriodicalIF":3.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426860","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}
Sustainable development is a pressing global concern, particularly in densely populated nations like China, where rural-to-urban migration poses challenges to sustainable land use. This study examines the finite nature of land resources and suggests that encouraging farmers to relinquish rural housing land can improve economic productivity and enhance the efficient utilization of rural areas. Based in the field investigations conducted in Dongtai City, Jiangsu Province, employing in-depth interviews and questionnaire surveys, the research identifies three distinct stages in the rural household migration process: employment transition, residential relocation, and life integration. The findings reveal nuanced patterns: farmers in the employment transition phase exhibit lower intentions to withdraw from housing land, whereas those in the residential relocation phase demonstrate higher withdrawal intentions, which subsequently taper off during the life integration stage. Moreover, the study identifies a non-linear relationship between farmers' migration progression and their homestead withdrawal intentions, with intentions peaking at an intermediate stage before declining. The research highlights the need for policies that comprehensively address the dynamics of farmers' migration. Recommended strategies include implementing tailored compensation mechanisms and urban incentives to enhance the appeal of urban living. Such measures can facilitate smoother farmer migration and promote sustainable land use practices, contributing to overall societal sustainability.
{"title":"Understanding rural household migration and homestead exit intentions: Toward sustainable land use and development goals","authors":"Qing Han , Kexin Zhou , Zhongxing Guo , Rupesh Kumar","doi":"10.1016/j.gexplo.2024.107595","DOIUrl":"10.1016/j.gexplo.2024.107595","url":null,"abstract":"<div><div>Sustainable development is a pressing global concern, particularly in densely populated nations like China, where rural-to-urban migration poses challenges to sustainable land use. This study examines the finite nature of land resources and suggests that encouraging farmers to relinquish rural housing land can improve economic productivity and enhance the efficient utilization of rural areas. Based in the field investigations conducted in Dongtai City, Jiangsu Province, employing in-depth interviews and questionnaire surveys, the research identifies three distinct stages in the rural household migration process: employment transition, residential relocation, and life integration. The findings reveal nuanced patterns: farmers in the employment transition phase exhibit lower intentions to withdraw from housing land, whereas those in the residential relocation phase demonstrate higher withdrawal intentions, which subsequently taper off during the life integration stage. Moreover, the study identifies a non-linear relationship between farmers' migration progression and their homestead withdrawal intentions, with intentions peaking at an intermediate stage before declining. The research highlights the need for policies that comprehensively address the dynamics of farmers' migration. Recommended strategies include implementing tailored compensation mechanisms and urban incentives to enhance the appeal of urban living. Such measures can facilitate smoother farmer migration and promote sustainable land use practices, contributing to overall societal sustainability.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107595"},"PeriodicalIF":3.4,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312981","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}
Pub Date : 2024-09-21DOI: 10.1016/j.gexplo.2024.107580
Ming Ding , Dinusha Vatsalan , Ignacio Gonzalez-Alvarez , Sirine M'rabet , Paul Tyler , Jens Klump
In mineral exploration, the exploration-discovery-mining (EDM) cycle may take 10–13 years. New and innovative approaches that can shorten the EDM cycle are fundamental to boosting the supply of mineral resources in the global market. In this paper, we propose a methodology for accelerating the EDM cycle by enabling confidentiality-preserving minerals data sharing, potentially shortening the exploration and discovery parts of the cycle. However, it is a highly challenging problem due to the need to balance diverse aspects related to the loss of confidential information and protecting competitive advantage. We investigate how data confidentiality risk assessment and data obfuscation technologies can be brought together to enable the sharing of otherwise sensitive data. We have defined several metrics to quantify the data confidentiality loss and utility gain in sharing data and developed various methods to obfuscate data by suppressing or sampling values. The confidentiality loss and utility loss caused by different obfuscation methods have been studied and empirically validated using a real-life mineral dataset provided by an Australian minerals company. Our proposed methods will enable mining and exploration companies to make informed decisions on what and how much information could be shared to achieve mutual benefits in mineral exploration at an acceptable cost of data confidentiality loss.
{"title":"Trusted data sharing for mineral exploration and mining tenements","authors":"Ming Ding , Dinusha Vatsalan , Ignacio Gonzalez-Alvarez , Sirine M'rabet , Paul Tyler , Jens Klump","doi":"10.1016/j.gexplo.2024.107580","DOIUrl":"10.1016/j.gexplo.2024.107580","url":null,"abstract":"<div><div>In mineral exploration, the exploration-discovery-mining (EDM) cycle may take 10–13 years. New and innovative approaches that can shorten the EDM cycle are fundamental to boosting the supply of mineral resources in the global market. In this paper, we propose a methodology for accelerating the EDM cycle by enabling confidentiality-preserving minerals data sharing, potentially shortening the exploration and discovery parts of the cycle. However, it is a highly challenging problem due to the need to balance diverse aspects related to the loss of confidential information and protecting competitive advantage. We investigate how data confidentiality risk assessment and data obfuscation technologies can be brought together to enable the sharing of otherwise sensitive data. We have defined several metrics to quantify the data confidentiality loss and utility gain in sharing data and developed various methods to obfuscate data by suppressing or sampling values. The confidentiality loss and utility loss caused by different obfuscation methods have been studied and empirically validated using a real-life mineral dataset provided by an Australian minerals company. Our proposed methods will enable mining and exploration companies to make informed decisions on what and how much information could be shared to achieve mutual benefits in mineral exploration at an acceptable cost of data confidentiality loss.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107580"},"PeriodicalIF":3.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318537","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}
Pub Date : 2024-09-21DOI: 10.1016/j.gexplo.2024.107590
Pan-Pan Niu , Shao-Yong Jiang , Manuel Muñoz
The Sichuan-Yunnan-Guizhou (Chuan-Dian-Qian) region represents the largest Mississippi Valley-type (MVT) Pb-Zn-Ge metallogenic province in China, including giant Huize and Maoping deposits. Research has suggested that Ge is incorporated primarily into the sphalerite lattice in the form of element substitution, and few Ge-bearing minerals have been reported in these deposits. We identified numerous sphalerite colors in Huize and Maoping and further found Ge-bearing minerals in black (C1) sphalerite. These Ge-bearing minerals are randomly distributed and have regular mineral morphologies, suggesting potential co-precipitation with C1 sphalerite rather than formation during later metamorphism and oxidation. One Ge-bearing mineral, argutite (GeO2), is found in Huize C1 sphalerite, which occurs in an isolated distribution or is locally associated with pyrite and hematite. Two Ge-bearing minerals, brunogeierite (GeFe2O4) and argutite (GeO2), are found in the Maoping C1 sphalerite. Brunogeierite is more abundant than argutite and is commonly associated with pyrite and rarely with argutite. The petrography and elemental composition confirmed that the C1 sphalerite in Huize and Maoping is the earliest formed sphalerite with the highest formation temperature. This suggests that high temperatures favor the precipitation of argutite and brunogeierite. However, slight variations in sulfur and oxygen fugacity may have resulted in discrepancies in the occurrence of Ge-bearing minerals between the Huize and Maoping deposits. According to the fluid mixing metallogenic model in the Chuan–Dian–Qian region, we posit that Ge-oxide mineral precipitation benefited from the initial stage of fluid mixing between Ge-bearing reduced fluid and oxidized basinal brine. This is also consistent with the findings that argutite and brunogeierite are exclusively associated with C1 sphalerite. As fluid mixing progresses, Ge is incorporated into the sphalerite lattice via element substitution. The newly discovered independent Ge minerals (argutite and brunogeierite) present greater economic potential than Ge-rich sphalerite does, thereby offering significant insights into the enrichment mechanism of Ge and the further utilization of Ge resources.
四川-云南-贵州（川滇黔）地区是中国最大的密西西比河谷型（MVT）铅锌锗成矿省，包括巨大的会泽和茅坪矿床。研究表明，Ge 主要以元素置换的形式融入闪锌矿晶格中，而这些矿床中很少有含 Ge 矿物的报道。我们在会泽和茅坪发现了多种颜色的闪锌矿，并在黑色（C1）闪锌矿中进一步发现了含锗矿物。这些含Ge矿物随机分布，矿物形态规则，表明可能是与C1闪锌矿共沉淀，而不是在后期变质和氧化过程中形成的。在会泽 C1 闪锌矿中发现了一种含 Ge 的矿物--方铅矿 (GeO2)，这种矿物呈孤立分布或局部与黄铁矿和赤铁矿伴生。在茅坪 C1 闪锌矿中发现了两种含 Ge 的矿物，即布鲁诺盖铁矿（GeFe2O4）和方铁矿（GeO2）。褐铁矿的含量高于绿泥石，通常与黄铁矿伴生，很少与绿泥石伴生。岩石学和元素组成证实，会泽和茅坪的C1闪锌矿是形成最早、形成温度最高的闪锌矿。这表明高温有利于辉石和布氏闪长岩的沉淀。然而，硫和氧富集度的细微差别可能导致会泽和茅坪矿床含 Ge 矿物的出现存在差异。根据川滇黔地区流体混合成矿模式，我们推测含Ge的还原流体与氧化基底盐水在流体混合的初始阶段有利于Ge-氧化物矿物的沉淀。这也与芒硝和布卢诺盖铁矿只与 C1 闪锌矿伴生的发现相一致。随着流体混合的进行，Ge 通过元素置换被纳入闪锌矿晶格。与富含 Ge 的闪锌矿相比，新发现的独立 Ge 矿物（方铅矿和布卢诺盖铁矿）具有更大的经济潜力，从而为 Ge 的富集机制和进一步利用 Ge 资源提供了重要启示。
{"title":"Newly discovered germanium minerals in Huize and Maoping MVT PbZn deposits in Southwest China: Implications for the germanium enrichment mechanism and exploration","authors":"Pan-Pan Niu , Shao-Yong Jiang , Manuel Muñoz","doi":"10.1016/j.gexplo.2024.107590","DOIUrl":"10.1016/j.gexplo.2024.107590","url":null,"abstract":"<div><div>The Sichuan-Yunnan-Guizhou (Chuan-Dian-Qian) region represents the largest Mississippi Valley-type (MVT) Pb-Zn-Ge metallogenic province in China, including giant Huize and Maoping deposits. Research has suggested that Ge is incorporated primarily into the sphalerite lattice in the form of element substitution, and few Ge-bearing minerals have been reported in these deposits. We identified numerous sphalerite colors in Huize and Maoping and further found Ge-bearing minerals in black (C1) sphalerite. These Ge-bearing minerals are randomly distributed and have regular mineral morphologies, suggesting potential co-precipitation with C1 sphalerite rather than formation during later metamorphism and oxidation. One Ge-bearing mineral, argutite (GeO<sub>2</sub>), is found in Huize C1 sphalerite, which occurs in an isolated distribution or is locally associated with pyrite and hematite. Two Ge-bearing minerals, brunogeierite (GeFe<sub>2</sub>O<sub>4</sub>) and argutite (GeO<sub>2</sub>), are found in the Maoping C1 sphalerite. Brunogeierite is more abundant than argutite and is commonly associated with pyrite and rarely with argutite. The petrography and elemental composition confirmed that the C1 sphalerite in Huize and Maoping is the earliest formed sphalerite with the highest formation temperature. This suggests that high temperatures favor the precipitation of argutite and brunogeierite. However, slight variations in sulfur and oxygen fugacity may have resulted in discrepancies in the occurrence of Ge-bearing minerals between the Huize and Maoping deposits. According to the fluid mixing metallogenic model in the Chuan–Dian–Qian region, we posit that Ge-oxide mineral precipitation benefited from the initial stage of fluid mixing between Ge-bearing reduced fluid and oxidized basinal brine. This is also consistent with the findings that argutite and brunogeierite are exclusively associated with C1 sphalerite. As fluid mixing progresses, Ge is incorporated into the sphalerite lattice via element substitution. The newly discovered independent Ge minerals (argutite and brunogeierite) present greater economic potential than Ge-rich sphalerite does, thereby offering significant insights into the enrichment mechanism of Ge and the further utilization of Ge resources.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107590"},"PeriodicalIF":3.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314304","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}
The Paleoproterozoic is known to host significant sedimentary manganese accumulations deposited in peri-cratonic areas. The depositional environments, the source of Mn and the geometry of the basins are often poorly understood, although they are key aspects in understanding the origin of these strategic resources. We investigate the Mn-rich graphitic metasediments of the Ampanihy district (South Madagascar) to characterize depositional conditions and to identify potential hydrothermal alteration. The results show that the ore is predominantly composed of Mn silicates (spessartine, rhodonite) with accessory jacobsite and pyrophanite varieties rich in Zn close to the Ampanihy shear zone. Geochemical data suggest that the source material in the eastern domain (Ankara) of the district is more crustal in origin than sediments in the western part of the district (Vohidrakitsy, Bekily). The Ankara deposits have chemical characteristics that are close to many other Paleoproterozoic Mn deposits and can be considered as relatively unaltered and fits with the euxinic model. The western domain of the Ampanihy district shows strong hydrothermal overprinting, with significant enrichment in Zn, Ba and Sb, resulting from post-depositional hydrothermal alteration along the proto-Ampanihy shear zone. This event took place at some stage between the deposition of the sediments (c. 1.9‐1.7 Ga) and the suture of the Vohibory and Androyen domains (c. 0.63–0.60 Ma). Based on our data, we propose a new discrimination plot, (La/Lu)PAAS vs Zn/Ni, which helps in the identification of sediment sources and the recognition of hydrothermal overprinting.
{"title":"Depositional setting and hydrothermal alteration of Paleoproterozoic manganiferous metasedimentary rocks in the Ampanihy district (Southern Madagascar)","authors":"Augustin Dekoninck , Thierry De Putter , Gilles Ruffet , Florias Mees , Yishen Zhang , Olivier Namur , Julie Kapoma","doi":"10.1016/j.gexplo.2024.107579","DOIUrl":"10.1016/j.gexplo.2024.107579","url":null,"abstract":"<div><p>The Paleoproterozoic is known to host significant sedimentary manganese accumulations deposited in peri-cratonic areas. The depositional environments, the source of Mn and the geometry of the basins are often poorly understood, although they are key aspects in understanding the origin of these strategic resources. We investigate the Mn-rich graphitic metasediments of the Ampanihy district (South Madagascar) to characterize depositional conditions and to identify potential hydrothermal alteration. The results show that the ore is predominantly composed of Mn silicates (spessartine, rhodonite) with accessory jacobsite and pyrophanite varieties rich in Zn close to the Ampanihy shear zone. Geochemical data suggest that the source material in the eastern domain (Ankara) of the district is more crustal in origin than sediments in the western part of the district (Vohidrakitsy, Bekily). The Ankara deposits have chemical characteristics that are close to many other Paleoproterozoic Mn deposits and can be considered as relatively unaltered and fits with the euxinic model. The western domain of the Ampanihy district shows strong hydrothermal overprinting, with significant enrichment in Zn, Ba and Sb, resulting from post-depositional hydrothermal alteration along the proto-Ampanihy shear zone. This event took place at some stage between the deposition of the sediments (c. 1.9‐1.7 Ga) and the suture of the Vohibory and Androyen domains (c. 0.63–0.60 Ma). Based on our data, we propose a new discrimination plot, (La/Lu)<sub>PAAS</sub> vs Zn/Ni, which helps in the identification of sediment sources and the recognition of hydrothermal overprinting.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107579"},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238448","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}
Pub Date : 2024-09-05DOI: 10.1016/j.gexplo.2024.107581
Sung Kyung Hong , Yuri Kim , Yoon-Mi Kim
Deep-sea sediments with an abundance bioapatites and Fe–Mn (oxyhydr)oxides in the Pacific Ocean have been considered potential reservoirs of rare earth elements and yttrium (REY). However, comprehensive assessment of the resource potential of REY in deep-sea sediments with Fe–Mn (oxyhydr)oxides throughout the Pacific Ocean is limited due to difficulties in accurately predicting the distribution of extensive Fe–Mn (oxyhydr)oxides and the associated REY. In this study, we predicted the prospective area and resource potential of REY-rich sediments with Fe–Mn (oxyhydr)oxides by considering multiple factors that control REY enrichment based on data from International Ocean Discovery Program (IODP) samples and previous research. According to the distribution map inferred by comprehensively evaluating lithology (clay sediment), hydrothermal fluid influence (δ3He), and water depth (bathymetry), deep-sea sediments with Fe–Mn (oxyhydr)oxides, which have higher than 1000 ppm REY concentration, are distributed in the vicinity of the East Pacific Ridge within a water depth range of 4000–4600 m, and their distribution area is estimated to be approximately 1.1 million km2. If the sedimentation rate (<1.5 m/Myr) is considered, which is a crucial factor influencing REY enrichment, we can achieve a more precise assessment of their distribution area. Assuming a recovery depth of only 1 m, the REY resource amount was estimated to be approximately >450 million tons of REY oxide. Even without accounting for REY resource amount associated with bioapatite, the minimum REY resource amount estimated in this study exceed the world's current land reserves. Furthermore, these sediments contain a significant abundance of industrially important heavy REY, accounting for 53 % of REY resources. This implies that the deep-sea sediments with Fe–Mn (oxyhydr)oxides in the Pacific Ocean are a promising resource of REY. Our findings will serve as essential information for the technological progress required in the exploration and development of REY resources in deep-sea sediments in the future.
太平洋富含生物磷灰石和铁-锰（氧化物）氧化物的深海沉积物一直被认为是稀土元素和钇（REY）的潜在储藏地。然而，由于难以准确预测大面积铁-锰（氧水）氧化物及相关稀土元素的分布，对整个太平洋含有铁-锰（氧水）氧化物的深海沉积物中稀土元素资源潜力的全面评估受到了限制。在本研究中，我们根据国际大洋发现计划（IODP）样品数据和以往研究，通过考虑控制REY富集的多种因素，预测了富含铁-锰（氧水）氧化物的REY沉积物的远景区和资源潜力。根据综合评价岩性（粘土沉积）、热液影响（δ3He）、水深（水深测量）等因素推断出的分布图，REY浓度高于1000ppm的氧化锰铁深海沉积物分布在东太平洋海脊附近4000-4600米水深范围内，估计分布面积约110万平方公里。如果考虑到沉积速率（1.5 m/Myr）这一影响 REY 富集的关键因素，我们就可以更精确地评估它们的分布面积。假设回收深度仅为 1 米，REY 资源量估计约为 4.5 亿吨氧化 REY。即使不考虑与生物磷灰石相关的 REY 资源量，本研究估算的最低 REY 资源量也超过了目前世界的陆地储量。此外，这些沉积物还含有大量工业上重要的重质 REY，占 REY 资源量的 53%。这意味着太平洋含有铁-锰（氧氢）氧化物的深海沉积物是一种很有潜力的 REY 资源。我们的研究结果将为今后深海沉积物中 REY 资源的勘探和开发所需的技术进步提供重要信息。
{"title":"Assessment of REY resource potential in deep-sea sediments with Fe–Mn (oxyhydr)oxides in the Pacific Ocean","authors":"Sung Kyung Hong , Yuri Kim , Yoon-Mi Kim","doi":"10.1016/j.gexplo.2024.107581","DOIUrl":"10.1016/j.gexplo.2024.107581","url":null,"abstract":"<div><p>Deep-sea sediments with an abundance bioapatites and Fe–Mn (oxyhydr)oxides in the Pacific Ocean have been considered potential reservoirs of rare earth elements and yttrium (REY). However, comprehensive assessment of the resource potential of REY in deep-sea sediments with Fe–Mn (oxyhydr)oxides throughout the Pacific Ocean is limited due to difficulties in accurately predicting the distribution of extensive Fe–Mn (oxyhydr)oxides and the associated REY. In this study, we predicted the prospective area and resource potential of REY-rich sediments with Fe–Mn (oxyhydr)oxides by considering multiple factors that control REY enrichment based on data from International Ocean Discovery Program (IODP) samples and previous research. According to the distribution map inferred by comprehensively evaluating lithology (clay sediment), hydrothermal fluid influence (δ<sup>3</sup>He), and water depth (bathymetry), deep-sea sediments with Fe–Mn (oxyhydr)oxides, which have higher than 1000 ppm REY concentration, are distributed in the vicinity of the East Pacific Ridge within a water depth range of 4000–4600 m, and their distribution area is estimated to be approximately 1.1 million km<sup>2</sup>. If the sedimentation rate (<1.5 m/Myr) is considered, which is a crucial factor influencing REY enrichment, we can achieve a more precise assessment of their distribution area. Assuming a recovery depth of only 1 m, the REY resource amount was estimated to be approximately >450 million tons of REY oxide. Even without accounting for REY resource amount associated with bioapatite, the minimum REY resource amount estimated in this study exceed the world's current land reserves. Furthermore, these sediments contain a significant abundance of industrially important heavy REY, accounting for 53 % of REY resources. This implies that the deep-sea sediments with Fe–Mn (oxyhydr)oxides in the Pacific Ocean are a promising resource of REY. Our findings will serve as essential information for the technological progress required in the exploration and development of REY resources in deep-sea sediments in the future.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107581"},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375674224001973/pdfft?md5=eb5d82f80ddf848787b5947f9b2a4375&pid=1-s2.0-S0375674224001973-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163546","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}
Pub Date : 2024-09-03DOI: 10.1016/j.gexplo.2024.107578
Martin Yan Hei Li , Jiacheng Liu , Wei Tan , Jia-Xi Zhou , Mei-Fu Zhou
With a growing demand for the rare earth elements (REE), exploration of regolith-hosted REE resources worldwide has been thriving in recent years and development of a rapid and reliable field-based tool will greatly facilitate the survey and exploration. In this study, we use visible and short-wave infrared (VNIR-SWIR) reflectance spectroscopy to comprehensively evaluate the applicability of the technique to explore regolith-hosted REE resources, exemplified by three representative regolith-hosted REE deposits in China. Neodymium among the REE shows reliably detectable spectral features in the VNIR-SWIR spectroscopy down to concentrations of 10–50 ppm in field samples with heterogeneous mineral grain sizes. The Nd spectral intensity of electronic transition at the band of ∼800 nm is correlated with bulk Nd concentrations and can be used as semi-quantitative indicators for the Nd concentrations, thereby the total REE in regolith. Moreover, VNIR-SWIR spectroscopy is demonstrated to be capable of delineating favorable ore-bearing mineralogy by characterizing the abundance and type of clay minerals and Fe (oxyhydr)oxides, and the crystallinity of kaolinite-group minerals. However, the Nd spectral features of samples with high bulk Fe2O3 contents (>3 wt%) are significantly masked due to overlapping by the strong absorption features of ferric (oxyhydr)oxides. VNIR-SWIR spectroscopy is deemed to be applicable to the exploration of regolith-hosted REE resources developed from Fe-poor felsic rocks.
{"title":"Characterization of regolith-hosted rare earth element deposits using reflectance spectroscopy: Framework towards an efficient and reliable field exploration tool","authors":"Martin Yan Hei Li , Jiacheng Liu , Wei Tan , Jia-Xi Zhou , Mei-Fu Zhou","doi":"10.1016/j.gexplo.2024.107578","DOIUrl":"10.1016/j.gexplo.2024.107578","url":null,"abstract":"<div><p>With a growing demand for the rare earth elements (REE), exploration of regolith-hosted REE resources worldwide has been thriving in recent years and development of a rapid and reliable field-based tool will greatly facilitate the survey and exploration. In this study, we use visible and short-wave infrared (VNIR-SWIR) reflectance spectroscopy to comprehensively evaluate the applicability of the technique to explore regolith-hosted REE resources, exemplified by three representative regolith-hosted REE deposits in China. Neodymium among the REE shows reliably detectable spectral features in the VNIR-SWIR spectroscopy down to concentrations of 10–50 ppm in field samples with heterogeneous mineral grain sizes. The Nd spectral intensity of electronic transition at the band of ∼800 nm is correlated with bulk Nd concentrations and can be used as semi-quantitative indicators for the Nd concentrations, thereby the total REE in regolith. Moreover, VNIR-SWIR spectroscopy is demonstrated to be capable of delineating favorable ore-bearing mineralogy by characterizing the abundance and type of clay minerals and Fe (oxyhydr)oxides, and the crystallinity of kaolinite-group minerals. However, the Nd spectral features of samples with high bulk Fe<sub>2</sub>O<sub>3</sub> contents (>3 wt%) are significantly masked due to overlapping by the strong absorption features of ferric (oxyhydr)oxides. VNIR-SWIR spectroscopy is deemed to be applicable to the exploration of regolith-hosted REE resources developed from Fe-poor felsic rocks.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107578"},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375674224001948/pdfft?md5=23886a07f533f0c5a3e9dc0aef032662&pid=1-s2.0-S0375674224001948-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238449","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}
Arsenic (As) and mercury (Hg) are highly toxic contaminants whereas selenium (Se) is both an essential trace element and potentially harmful at higher concentrations. The hyper-saline lakes of southern Bolivian Altiplano, which are ecological niches for endemic species, are also expected to be enriched in these toxic trace elements. The biogeochemistry of As, Hg, and Se in such high-altitude extreme environments (e.g., high UV radiation and salt content) remains poorly understood. In this study, we investigated the concentrations and chemical forms (speciation) of As, Hg, and Se in sediment, water, and air samples of Lagunas Colorada (LC), Verde (LV), and Blanca (LB) in the South Lipez region (>4200 m a.s.l.). We compared them with the repartition of biodiversity (invertebrates, algae, and bacteria). Extreme As concentrations were found in water (up to 82 mg L−1), and the main As species was inorganic As(V), with neither biogenic methylated As nor volatile As forms being detected in water and air, respectively. Se concentrations in water were of 0.1 to 1.4 μg L−1, and Se existed under different redox states, i.e., Se(IV), Se(VI), and reduced Se (0, -II), including biogenic methylated Se(-II) (trimethyl selenonium). Volatile Se compounds (e.g., dimethyl selenide) were detected in water and air samples. Hg was enriched in the surface water (6 to 30 ng L−1) compared to other regional water bodies, and a significant amount of methyl-Hg and gaseous Hg(0) was detected. The drastic disparity between As, Se and Hg concentrations and speciation between lakes has important implications for their cycling in these extreme aquatic systems. While As mostly accumulated in its oxidized and non-volatile form, Hg and Se concentrations can be controlled by significant conversion to reduced and methylated forms, allowing efficient evasion to the atmosphere. Finally, the salinity, including major ions, and high levels of As were among the main drivers of biodiversity repartition between lakes.
{"title":"Arsenic, selenium, and mercury speciation in hypersaline lakes of the Andean Altiplano: Link between extreme levels and biodiversity repartition","authors":"Stéphane Guédron , Julie Tolu , David Amouroux , Emmanuel Tessier , Carlos Molina , Maïté Bueno , Adrien Mestrot , Delphine Tisserand , Dario Acha","doi":"10.1016/j.gexplo.2024.107577","DOIUrl":"10.1016/j.gexplo.2024.107577","url":null,"abstract":"<div><p>Arsenic (As) and mercury (Hg) are highly toxic contaminants whereas selenium (Se) is both an essential trace element and potentially harmful at higher concentrations. The hyper-saline lakes of southern Bolivian Altiplano, which are ecological niches for endemic species, are also expected to be enriched in these toxic trace elements. The biogeochemistry of As, Hg, and Se in such high-altitude extreme environments (e.g., high UV radiation and salt content) remains poorly understood. In this study, we investigated the concentrations and chemical forms (speciation) of As, Hg, and Se in sediment, water, and air samples of Lagunas Colorada (LC), Verde (LV), and Blanca (LB) in the South Lipez region (>4200 m a.s.l.). We compared them with the repartition of biodiversity (invertebrates, algae, and bacteria). Extreme As concentrations were found in water (up to 82 mg L<sup>−1</sup>), and the main As species was inorganic As(V), with neither biogenic methylated As nor volatile As forms being detected in water and air, respectively. Se concentrations in water were of 0.1 to 1.4 μg L<sup>−1</sup>, and Se existed under different redox states, i.e., Se(IV), Se(VI), and reduced Se (0, -II), including biogenic methylated Se(-II) (trimethyl selenonium). Volatile Se compounds (e.g., dimethyl selenide) were detected in water and air samples. Hg was enriched in the surface water (6 to 30 ng L<sup>−1</sup>) compared to other regional water bodies, and a significant amount of methyl-Hg and gaseous Hg(0) was detected. The drastic disparity between As, Se and Hg concentrations and speciation between lakes has important implications for their cycling in these extreme aquatic systems. While As mostly accumulated in its oxidized and non-volatile form, Hg and Se concentrations can be controlled by significant conversion to reduced and methylated forms, allowing efficient evasion to the atmosphere. Finally, the salinity, including major ions, and high levels of As were among the main drivers of biodiversity repartition between lakes.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107577"},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375674224001936/pdfft?md5=2bad7cd099edd9bdeb16e8bcb173b5fd&pid=1-s2.0-S0375674224001936-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163538","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}
Pub Date : 2024-09-03DOI: 10.1016/j.gexplo.2024.107576
Zeling Wang , Xuebing Zhang , Zhilei Cui , Weidong Zhang , Yaochao Sun , Yingting Liu
The Kumishi area is located in the eastern part of the South Tianshan Orogen, which hosts several gold deposits and has substantial gold discovery potential. The timing of gold mineralization at Kumishi, however, has been poorly constrained owing to the absence of suitable dating minerals. Hydrothermal activity at Wuzunbulake is divided into the pre-ore stage 1 pyrite-quartz, syn-ore stage 2 quartz(-sulfide) and post-ore stage 3 quartz-calcite alteration/mineralization. Three types of pyrite have been recognized, i.e., Py1 (stage 1), Py2 (stage 2), and PyWR (from wallrock). Our in-situ RbSr dating on stage 2 sericite yielded an isochron age of 351.0 ± 17.4 Ma, indicating Early Carboniferous gold mineralization. Py1 and Py2 have δ34SΣS = 8.28–15.97 ‰ (avg. 12.88 ‰) and 6.92–8.70 ‰ (avg. 7.67 ‰), respectively, indicating that the sulfur in Py1 was metamorphic fluid sourced, while that of Py2 may have a mixed metamorphic fluid and wallrock source (0.84–3.27 ‰; avg. 2.31 ‰). For Py1, its contents of Au, As, Ag, Bi, Co, Cu, Mn, Ni, Pb, Sb, Tl are the lowest. Py2 has significantly higher Au-As-Ag, slightly higher Co-Cu-Ni-Sb-Tl, but lower Bi-Mn-Pb contents than those in PyWR. Considering also the sulfur isotope features, we considered that Py1 was primarily originated from the initial ore-forming fluid, and Py2 was derived from both the ore fluid and PyWR, with the former being more important and represents the source of gold. Based on that Py2 was formed by metasomatism on the PyWR margin and the element spatial coupling characteristics shown in EPMA geochemical maps, we inferred that the Au enrichment and precipitation are associated with fluid-rock reactions. The initial ore fluid is likely featured by the enrichments in Au, As, Ag, Co, Cu, Ni, Sb, Tl, and depletions in Bi, Mn, and Pb. The Wuzunbulake is best classified as an orogenic gold deposit based on its tectonic background, wallrock alteration style, and the ore-fluid source and characteristics.
{"title":"The Carboniferous Wuzunbulake orogenic gold deposit in South Tianshan Orogen (NW China): Sericite RbSr geochronology, pyrite geochemistry, and metallogeny","authors":"Zeling Wang , Xuebing Zhang , Zhilei Cui , Weidong Zhang , Yaochao Sun , Yingting Liu","doi":"10.1016/j.gexplo.2024.107576","DOIUrl":"10.1016/j.gexplo.2024.107576","url":null,"abstract":"<div><p>The Kumishi area is located in the eastern part of the South Tianshan Orogen, which hosts several gold deposits and has substantial gold discovery potential. The timing of gold mineralization at Kumishi, however, has been poorly constrained owing to the absence of suitable dating minerals. Hydrothermal activity at Wuzunbulake is divided into the pre-ore stage 1 pyrite-quartz, <em>syn</em>-ore stage 2 quartz(-sulfide) and post-ore stage 3 quartz-calcite alteration/mineralization. Three types of pyrite have been recognized, i.e., Py<sub>1</sub> (stage 1), Py<sub>2</sub> (stage 2), and Py<sub>WR</sub> (from wallrock). Our in-situ Rb<img>Sr dating on stage 2 sericite yielded an isochron age of 351.0 ± 17.4 Ma, indicating Early Carboniferous gold mineralization. Py<sub>1</sub> and Py<sub>2</sub> have δ<sup>34</sup>S<sub>ΣS</sub> = 8.28–15.97 ‰ (avg. 12.88 ‰) and 6.92–8.70 ‰ (avg. 7.67 ‰), respectively, indicating that the sulfur in Py<sub>1</sub> was metamorphic fluid sourced, while that of Py<sub>2</sub> may have a mixed metamorphic fluid and wallrock source (0.84–3.27 ‰; avg. 2.31 ‰). For Py<sub>1</sub>, its contents of Au, As, Ag, Bi, Co, Cu, Mn, Ni, Pb, Sb, Tl are the lowest. Py<sub>2</sub> has significantly higher Au-As-Ag, slightly higher Co-Cu-Ni-Sb-Tl, but lower Bi-Mn-Pb contents than those in Py<sub>WR</sub>. Considering also the sulfur isotope features, we considered that Py<sub>1</sub> was primarily originated from the initial ore-forming fluid, and Py<sub>2</sub> was derived from both the ore fluid and Py<sub>WR</sub>, with the former being more important and represents the source of gold. Based on that Py<sub>2</sub> was formed by metasomatism on the Py<sub>WR</sub> margin and the element spatial coupling characteristics shown in EPMA geochemical maps, we inferred that the Au enrichment and precipitation are associated with fluid-rock reactions. The initial ore fluid is likely featured by the enrichments in Au, As, Ag, Co, Cu, Ni, Sb, Tl, and depletions in Bi, Mn, and Pb. The Wuzunbulake is best classified as an orogenic gold deposit based on its tectonic background, wallrock alteration style, and the ore-fluid source and characteristics.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107576"},"PeriodicalIF":3.4,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142167190","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}
Pub Date : 2024-09-02DOI: 10.1016/j.gexplo.2024.107575
Wuhui Jia , Kai Liu , Jinkai Yan , Yaoyao Zhang , Jue Tong , Kun Yu , Shouchuan Zhang , Luyao Wang , Chenghua Yu
The hydrogeochemical signature of the discharged water can reveal significant information on the circulation and evolution of geothermal water, which can further guide the exploration and utilization of geothermal water resources. In this study, the source of major ions, reservoir temperature, and cycle time of geothermal fluids were clarified by the Ion relationship analysis, integrated multicomponent solute geothermometry method, and 14C isotope analysis, respectively, in the Wugongshan area of South China. Results show that the eastern and western parts of the Wugongshan area have distinct types of geothermal fluids, i.e. HCO3-Na and SO4HCO3-Na, respectively. The major source of HCO3− and Na+ is the hydrolysis of silicate minerals, partially accompanied by cation exchange. While gypsum hydrolysis and sulfide oxidation are the primary producers of SO42−. Moreover, higher TDS, PH, and degree of cation exchange of geothermal fluids were found in the western part than that in the eastern part. The reservoir temperatures in the eastern and western portions are comparable (115–150 °C). However, the cycle time of the geothermal fluids in the western part (15,743 years on average) is much greater than in the eastern part (2160 years on average), which is considered to be the main reason for the difference in hydrogeochemical characteristics. This study can provide theoretical support for the rational development and usage of geothermal water resources.
{"title":"The difference in hydrochemical characteristics of geothermal water between the eastern and western parts of the Wugongshan area and its genetic mechanism","authors":"Wuhui Jia , Kai Liu , Jinkai Yan , Yaoyao Zhang , Jue Tong , Kun Yu , Shouchuan Zhang , Luyao Wang , Chenghua Yu","doi":"10.1016/j.gexplo.2024.107575","DOIUrl":"10.1016/j.gexplo.2024.107575","url":null,"abstract":"<div><p>The hydrogeochemical signature of the discharged water can reveal significant information on the circulation and evolution of geothermal water, which can further guide the exploration and utilization of geothermal water resources. In this study, the source of major ions, reservoir temperature, and cycle time of geothermal fluids were clarified by the Ion relationship analysis, integrated multicomponent solute geothermometry method, and <sup>14</sup>C isotope analysis, respectively, in the Wugongshan area of South China. Results show that the eastern and western parts of the Wugongshan area have distinct types of geothermal fluids, i.e. HCO<sub>3</sub>-Na and SO<sub>4</sub>HCO<sub>3</sub>-Na, respectively. The major source of HCO<sub>3</sub><sup>−</sup> and Na<sup>+</sup> is the hydrolysis of silicate minerals, partially accompanied by cation exchange. While gypsum hydrolysis and sulfide oxidation are the primary producers of SO<sub>4</sub><sup>2−</sup>. Moreover, higher TDS, PH, and degree of cation exchange of geothermal fluids were found in the western part than that in the eastern part. The reservoir temperatures in the eastern and western portions are comparable (115–150 °C). However, the cycle time of the geothermal fluids in the western part (15,743 years on average) is much greater than in the eastern part (2160 years on average), which is considered to be the main reason for the difference in hydrogeochemical characteristics. This study can provide theoretical support for the rational development and usage of geothermal water resources.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"266 ","pages":"Article 107575"},"PeriodicalIF":3.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137197","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}
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