Journal of Geochemical Exploration最新文献

{"title":"Mineralogy and environmental geochemistry of copper slag from Butte, Montana","authors":"Christopher H. Gammons,&nbsp;Jenna Kaplan","doi":"10.1016/j.gexplo.2024.107599","DOIUrl":"10.1016/j.gexplo.2024.107599","url":null,"abstract":"<div><div>Herein we characterize the mineralogy, chemical composition, and environmental geochemistry of slag formed by historic (1880s to circa 1910) smelting of the copper-rich lodes of Butte, Montana. The air-cooled slag exists as monolithic “walls” that border Silver Bow Creek, the headwaters of the upper Clark Fork River Superfund site. The slag is mainly comprised of fayalite, hedenbergite, wollastonite, magnetite, and glass. Zinc is present at per cent levels in all of these phases. The overall high zinc content of the slag is partly due to the polymetallic character of the Butte ore bodies. Copper occurs mainly as tiny spheres, or “prills”, which are remnants of the molten Cu-sulfide matte that failed to separate from the slag during smelting. Minerals in the prills include bornite, chalcopyrite, chalcocite, pyrrhotite, pyrite, sphalerite, galena, elemental copper, and elemental silver. The prills are variably oxidized along shrinkage cracks that penetrate into the enclosing slag matrix. Secondary minerals, including hydrous ferric oxide and ferric clay, coat the cracks. Where the cracks meet the surface of the slag, secondary encrustations of calcite, Fe-Mn oxyhydroxides, and mixed Ca-Cu-Zn-Mn-Al-Fe sulfates have locally accumulated. Acid-base accounting tests show that the unweathered slag is non-acid-generating, with the acid potential from Fe-Cu sulfides offset by the neutralization potential of the Ca-Fe silicates (olivine, pyroxene). Interaction of the slag with synthetic precipitation (SPLP tests) confirms the slag's ability to buffer pH to values &gt;8. Nonetheless, the SPLP leachate solutions contain ppb levels of copper, arsenic, zinc, and lead that approach or exceed current regulatory standards for protection of aquatic life (Cu, Pb, Zn) and human health (As). Leaching experiments using Silver Bow Creek water show an increase in dissolved As and W, but variable results for Cu, Pb, and Zn. Leaching of the secondary sulfate-salt deposits produced much higher concentrations of dissolved metals and metalloids which could be a source of contamination to Silver Bow Creek during heavy rain events. Based on bulk analyses, some metals in the slag, including Fe, As, Co, Mn, Pb, Zn, and W, exceed USEPA screening levels for residential and/or urban soils. Leachates containing organic acids (TCLP tests) show Pb concentrations that approach levels for the slag to be classified as hazardous waste. Rather than removing the slag walls, which have value as a form of industrial architecture, an alternate remedy currently under evaluation is to divert Silver Bow Creek around the smelter site and preserve the slag as part of a non-motorized recreational trail system in the reclaimed Butte-Anaconda mine-scape.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107599"},"PeriodicalIF":3.4,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426863","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}

{"title":"Late mesozoic exhumation of silurian – Devonian and permian Ni-Co sulfide deposits in the East Kunlun orogenic belt: Constraints from zircon fission track ages","authors":"Xueyu Yan ,&nbsp;Yuxin Fan ,&nbsp;Qingsong Cai ,&nbsp;Minmin Gao ,&nbsp;Dengdong Lu ,&nbsp;Ke Bi ,&nbsp;Chuanying Zhu ,&nbsp;Mingjie Zhang ,&nbsp;Ying Wang ,&nbsp;Guangliang Yang ,&nbsp;Xiaohu Li ,&nbsp;Buqing Wang","doi":"10.1016/j.gexplo.2024.107591","DOIUrl":"10.1016/j.gexplo.2024.107591","url":null,"abstract":"<div><div>Ni-Co sulfide deposits of late Silurian – early Devonian and Permian ages hosted within in basic-ultrabasic rock bodies in the East Kunlun orogenic belt have been extensively investigated. Nevertheless, we have only a limited understanding of the history and dynamics of uplift, exhumation, and tectonic deformation of the basic-ultrabasic ore-bearing rock bodies of these Ni-Co sulfide deposits. We used the zircon fission track ages of seven samples obtained from basic-ultrabasic ore-bearing rocks to determine the timing of the exhumation of these Ni-Co sulfide deposits. Combining our results with published data on the timing of orogenesis, cooling events, magmatic activities, and basin infilling in adjacent areas, we conclude the following: 1) The ZFT ages obtained in this study indicate the exhumation during 169.6 ± 5.5–142.2 ± 3.2 Ma; 2) Combined with previous results, our data indicate that the exhumation during the Jurassic – Cretaceous occurred across a large area along the East Kunlun orogenic belt to the Alxa block; 3) The synchroneity of orogeny, magmatic activity, and basin infilling events suggests that the late Mesozoic exhumation was a geomorphological response to the Lhasa-Qiangtang collision driven by the breakup of Gondwanaland.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107591"},"PeriodicalIF":3.4,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426861","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}

{"title":"Mercury in the natural environment: Biogeochemical cycles and associated health risks","authors":"Amit Kumar ,&nbsp;Vinod Kumar ,&nbsp;Palak Bakshi ,&nbsp;Ripu Daman Parihar ,&nbsp;Maja Radziemska ,&nbsp;Rupesh Kumar","doi":"10.1016/j.gexplo.2024.107594","DOIUrl":"10.1016/j.gexplo.2024.107594","url":null,"abstract":"<div><div>Mercury (Hg) is an integral part of Earth's biogeochemical cycles, yet anthropogenic activities significantly elevate its environmental presence, posing considerable ecological and human health risks. Human exposure primarily arises from the consumption of Hg-contaminated freshwater and marine fish. The Minamata Convention on Mercury, initiated by the United Nations Environment Programme (UNEP), aims to mitigate global Hg emissions, reinforced by comprehensive monitoring efforts. The biogeochemical cycling of Hg is complex, encompassing intricate processes of distribution, transformation, and bioaccumulation that connect sources to exposure pathways. Thus, evaluating Hg biogeochemical behavior and potential environmental hazards is crucial in the global scientific fraternity. Although global policies address direct Hg emissions, comprehending its biogeochemical cycling remains challenging and continues to spur scientific investigation. Coal combustion is a significant source, accounting for approximately 60 % of Hg emissions, especially in geologically predisposed regions, with atmospheric deposition being a key factor, leading to elevated Hg levels in terrestrial soils. Health risks associated with Hg exposure are more acute in soil-contaminated environments than in aquatic systems, with ingestion posing greater risks than dermal contact. This review focuses on the biogeochemical cycling of Hg in the natural environment, highlighting contamination patterns and providing updated insights into Hg's impact on aquatic and terrestrial ecosystems.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107594"},"PeriodicalIF":3.4,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426859","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}

{"title":"Fluid inclusions and H–O isotopes of the super-large Nanyangtian tungsten deposit in southeastern Yunnan, southwestern China","authors":"Tao Ren ,&nbsp;Qi Zhang ,&nbsp;Cai-Yan Wang ,&nbsp;Die Wang ,&nbsp;Shen-Jin Guan","doi":"10.1016/j.gexplo.2024.107593","DOIUrl":"10.1016/j.gexplo.2024.107593","url":null,"abstract":"<div><div>The Nanyangtian deposit is a super-large reduced skarn tungsten deposit located in the Laojunshan W<img>Sn polymetallic ore province in southeastern Yunnan (SW China). The deposit is represented by three flat-lying mineralized zones formed vertically by the replacement of limestone or minor calcareous schist. The tungsten orebodies are mainly stratiform, lenticular, and vein types, hosted in the Paleoproterozoic Nanyangtian Formation. Three mineral formation stages have been identified based on the mineral assemblages and vein crosscutting relationships (pre-, syn-, and post-ore). The Nanyangtian is a calcic skarn deposit, dominated by a grossular-diopside-tremolite-actinolite assemblage. Scheelite, pyrrhotite, pyrite, and chalcopyrite are the main ore minerals. Detailed petrographic observations show three types of fluid inclusions (FIs) in various hydrothermal minerals: liquid-rich two-phase (type-I), gas-rich two-phase (type-II), daughter mineral-bearing three-phase (type-III). Their homogenization temperatures (193–298 °C) and salinities (1.2–9.3 wt% NaCl eq.) indicate that the Nanyangtian ore-forming fluids were of medium to low temperature and low salinity compared to the statistical data from representative skarn tungsten deposits in South China. Laser Raman microprobe analysis of the FIs shows that the inclusions are dominated by H₂O with minor CH₄ and N₂. The δD values (relative to Vienna-Standard Mean Ocean Water, VSMOW) of fluid inclusions and calculated δ¹⁸O_water values (relative to VSMOW) of the fluids in equilibrium with hydrothermal minerals are −105 to −69 ‰ and − 1.9 to 7.6 ‰, respectively. These oxygen–hydrogen isotopic compositions indicate that the ore-forming fluids were magmatic-derived, which may have metasomatized the Nanyangtian Formation carbonaceous calcareous rocks along interlayer structures to form the prograde skarn minerals. Then the fluids mixed with meteoric water migrated along faults to form the retrograde skarn and tungsten ore. Mixing of magmatic fluid with meteoric water is likely the main factor for the ore precipitation at Nanyangtian.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107593"},"PeriodicalIF":3.4,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322477","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}

{"title":"Characterization of lead and zinc in catchment sediments and their relationship with lead‑zinc mineralization from the Sino–Mongolian border region","authors":"Wei Wang ,&nbsp;Lanshi Nie ,&nbsp;Haibo Wang ,&nbsp;Xueqiu Wang ,&nbsp;Hanliang Liu ,&nbsp;Shojin Davaa ,&nbsp;Qinghua Chi ,&nbsp;Dongsheng Liu ,&nbsp;Jian Zhou ,&nbsp;Qinghai Hu ,&nbsp;Xinbin Cheng ,&nbsp;Yining Zhou","doi":"10.1016/j.gexplo.2024.107597","DOIUrl":"10.1016/j.gexplo.2024.107597","url":null,"abstract":"<div><div>The Sino–Mongolian border region is one of the most important metallogenic belts in Central Asia and is an important source of Au, Ag, Pb, Zn, Sn, Cu, and rare metals in southern Mongolia and northern China. The variations in Pb and Zn concentrations and their spatial distribution in the region can indirectly reflect the distribution pattern of mineral resources in the region and provide reference data for the exploration of elements associated with Pb and Zn (e.g., Au, Ag, Cu, and Mn). Moreover, Pb and Zn data are valuable in environmental research because the elements are persistent and potentially toxic heavy metals. Although numerous geological and geochemical surveys of Pb<img>Zn resources have been conducted in China, the Sino–Mongolian border region remains under studied. Therefore, in this study, we performed an integrated and comprehensive analytical study of single-element and combined Pb<img>Zn geochemical anomalies. A total of 10,452 catchment sediment samples were collected. Pb concentrations in the samples ranged from 1.90 to 494 mg/kg, while Zn concentrations ranged from 3.00 to 1940 mg/kg. Of these, the median and mean values for Pb were 19.4 mg/kg and 55.0 mg/kg, respectively, while the median and mean values for Zn were 19.9 mg/kg and 58.0 mg/kg, respectively. To characterize the concentration and spatial distribution of Pb and Zn in the study area, we conducted an exhaustive study across several dimensions, considering the geological setting, mineral development, and utilization, and explored the key factors affecting these characteristics. A total of 53 Pb, Zn geochemical anomalies (geochemical province/domain, Pb &gt; 23.1 mg/kg and Zn &gt; 75 mg/kg, &gt; Q85%), including 17 Pb<img>Zn combined geochemical anomalies, were identified in this study. The Pb<img>Zn combined geochemical anomalies were mainly concentrated in the Altai region in the west and the Daxinganling region in the east of the study area and are closely related to the distribution of known Pb<img>Zn deposits. The high-quality geochemical data produced during this study could be an important reference for future mineral exploration work and environmental change studies in the Sino–Mongolian border region.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107597"},"PeriodicalIF":3.4,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359026","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}

{"title":"Hidden deposit exploration using the tectono-geochemistry method in the western Xicheng ore field, China","authors":"Zhizhong Cheng ,&nbsp;Qiang Wang ,&nbsp;Junchen Liu ,&nbsp;Zhenshan Pang ,&nbsp;Tingjie Yan ,&nbsp;Zezhong Du ,&nbsp;Mingming Bing ,&nbsp;Huixiang Yuan ,&nbsp;Chenggui Lin","doi":"10.1016/j.gexplo.2024.107592","DOIUrl":"10.1016/j.gexplo.2024.107592","url":null,"abstract":"<div><div>Geochemical anomalies involve complex geological and geochemical processes. Integrating metallogenic processes into the interpretation of geochemical data can promote mineral exploration. In this study, 3080 subsamples were collected from the western Xicheng ore field and combined into 1312 composite samples using the tectono-geochemistry method. Nineteen elements were analyzed for each composite sample. Factor analysis based on the CLR-transformed data yielded four factors, including the Ag–Sb–Hg–Pb–Au–(B–Ba) association of F1, Zn–Cd–Pb association of F2, Bi–Sn–(Au–As) association of F3, and W–Sn–(Cu) association of F4. Thresholds of each factor were obtained using the concentration–number (C–N) fractal model. Six targets were delineated based on the factor anomaly maps, and one Pb–Zn and two Au deposits were discovered in Targets I and II, respectively. These discoveries and the good spatial correspondence between known deposits and anomalies provide compelling evidence for the effectiveness of the tectono-geochemistry method in the study area. More importantly, a model for the genetic relationship between geochemical anomalies and metallogenesis was constructed. The late tectonic-magmatic-hydrothermal transformation dominated the geochemical pattern in the study area. The degree of interaction between the Au-rich magmatic-hydrothermal fluids and SEDEX-style Pb–Zn mineralizations yielded leakage halos with various elemental assemblages. In addition, W–Sn anomalies may serve as auxiliary exploration indicators for Au mineralizations.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"267 ","pages":"Article 107592"},"PeriodicalIF":3.4,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322475","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}

{"title":"The science of food safety and their health impacts","authors":"Amit Kumar ,&nbsp;Vinod Kumar ,&nbsp;Danijela Arsenov ,&nbsp;Monika Thakur ,&nbsp;Ashok Kumar ,&nbsp;Ashish Khokhar ,&nbsp;Chandra Shekhar Seth ,&nbsp;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}

{"title":"Understanding rural household migration and homestead exit intentions: Toward sustainable land use and development goals","authors":"Qing Han ,&nbsp;Kexin Zhou ,&nbsp;Zhongxing Guo ,&nbsp;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}

{"title":"Trusted data sharing for mineral exploration and mining tenements","authors":"Ming Ding ,&nbsp;Dinusha Vatsalan ,&nbsp;Ignacio Gonzalez-Alvarez ,&nbsp;Sirine M'rabet ,&nbsp;Paul Tyler ,&nbsp;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}

{"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 ,&nbsp;Shao-Yong Jiang ,&nbsp;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 (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.</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}