Journal of Geochemical Exploration最新文献_第2页

Magnetite texture and composition in the Makeng Fe skarn deposit, Southeastern China 中国东南部马坑铁夕卡岩矿床磁铁矿结构与组成

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-09 DOI: 10.1016/j.gexplo.2026.107975

Jiaxing Hu , Jing Xu , Wei Zheng , Taiping Zhao , Huochun Shen , Bo Xing

Magnetite is the most important ore mineral in Fe skarn deposits. Its textural and compositional signatures effectively indicate the ore-forming environment and can fingerprint mineralization processes. The Makeng deposit is the largest Fe skarn deposit in southeastern China, which is a case study for constraining the mineralization process by using textures and composition of magnetite. Four generations of magnetite (MagI to MagIV) are distinguished in this deposit. The MagI and MagIII both show similar oscillatory zoning with abundant micro-nano silicate inclusions, however, the texture relationship indicates that MagI formed earlier than MagIII and they have different compositions as well as inclusion density. MagII contains randomly distributed pores and coarsened inclusions. In contrast, MagIV is clean and free of inclusions and pores. All four types of magnetite are of hydrothermal origin. However, they crystallized in distinct stages within different conditions. The MagI crystallized from a relatively high-temperature and supersaturated fluid enriched in Fe, Si, Ca, and Al. The formation of MagII is due to dissolution-reprecipitation of MagI. The MagIII was likely formed by continuous magmatic-hydrothermal pulse. However, the relatively low contents of Si, Al, and Ca lead to lower density of silicate inclusions compared to MagI. Finally, the MagIV formed under relatively low temperature and high oxygen fugacity conditions, and the low concentrations of Si, Al, Ca, and Mg within the fluids prevented the development of inclusions. Abundant silicate inclusions in Makeng magnetite indicate that the influence of inclusions on the occurrence of trace elements cannot be overlooked, which highlights the importance of petrographic study for understanding the trace element occurrence. Magnetite from Makeng also shows significant enrichment of Ga (average 45 ppm) and Co (average 30 ppm). Ga enrichment might primarily have been controlled by temperature and oxygen fugacity, whereas Co enrichment is constrained by other factors.

磁铁矿是铁夕卡岩矿床中最重要的矿石矿物。其结构和成分特征能有效指示成矿环境，并为成矿过程提供指纹。马坑铁矿是中国东南地区最大的铁夕卡岩矿床，是利用磁铁矿的结构和成分制约成矿作用的典型案例。该矿床分为4代磁铁矿（MagI ~ MagIV）。MagI和MagIII均表现出相似的振荡带，均含有丰富的微纳硅酸盐包裹体，但织构关系表明MagI比MagIII形成更早，且两者的成分和包裹体密度不同。MagII含有随机分布的孔隙和粗化的包裹体。相比之下，MagIV是干净的，没有夹杂物和孔隙。四种磁铁矿均为热液成因。然而，在不同的条件下，它们在不同的阶段结晶。MagI是由富含Fe、Si、Ca和Al的相对高温过饱和流体结晶而成。MagII的形成是由于MagI的溶解-再沉淀。MagIII可能是由连续的岩浆-热液脉冲形成的。然而，相对较低的Si、Al和Ca含量导致硅酸盐包裹体密度低于MagI。最后，MagIV是在相对较低的温度和高氧逸度条件下形成的，流体中低浓度的Si、Al、Ca和Mg阻止了包裹体的发育。马坑磁铁矿中丰富的硅酸盐包裹体表明包裹体对微量元素赋存状态的影响不容忽视，这凸显了岩石学研究对认识微量元素赋存状态的重要性。马坑磁铁矿中Ga（平均45 ppm）和Co（平均30 ppm）也有显著富集。Ga的富集可能主要受温度和氧逸度的控制，而Co的富集则受其他因素的制约。

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引用次数: 0

Geochemical evolution of the mineralizing fluids at the Tenke-Fungurume Mining District (DR Congo): Insights from microthermometry, crush-leach, and LA-ICP-MS analyses of fluid inclusions 刚果（金）Tenke-Fungurume矿区成矿流体的地球化学演化：来自流体包裹体显微测温、破碎浸出和LA-ICP-MS分析的见解

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-08 DOI: 10.1016/j.gexplo.2026.107971

Jessica Torres , Pascal Mambwe , Philippe Muchez

The Tenke-Fungurume mining district, located in the northern part of the Katanga Copperbelt, DR Congo, hosts numerous carbonate-quartz veins that demonstrate the pre-, syn-, and post-folding events related to the Lufilian Orogeny. Microthermometric and geochemical analyses of their contained fluid inclusions were performed to understand the fluid evolution throughout those phases. Primary fluid inclusions record a large range of T_h (149–372 °C) and salinity (37.1–59.9 wt% NaCl + KCl eq.) for all phases, which cannot be used to differentiate between successive mineralizing events. Laser ablation ICP-MS and crush-leach analysis invariably point to fluids originating from the progressive evaporation of seawater. Fluid chemistry was strongly controlled by intense fluid-rock interactions at high temperatures. All dolomite samples show major recrystallization patterns and generations, which testify to fluid flow events that likely affected the whole Katanga basin. High contents of Cu, Co, Ba, Zn, and Pb relative to Na were measured in primary fluid inclusions of all phases, suggesting mineralization was not restricted to discrete or unique events, but rather that the same hydrothermal ore-forming system operated over a long period during basin evolution and deformation.

Tenke-Fungurume矿区位于刚果民主共和国加丹加铜矿带的北部，拥有大量的碳酸盐-石英矿脉，这些矿脉显示了与卢菲连造山运动相关的前、同、后褶皱事件。对其所含流体包裹体进行了显微温度和地球化学分析，以了解这些阶段的流体演化。原生流体包裹体记录了所有相的大范围Th（149 ~ 372℃）和盐度（37.1 ~ 59.9 wt% NaCl + KCl eq.），不能用于区分连续的矿化事件。激光烧蚀ICP-MS和破碎浸出分析总是指向来自海水逐渐蒸发的流体。在高温下，流体化学受到强烈的流体-岩石相互作用的强烈控制。所有白云岩样品都显示出主要的再结晶模式和世代，这证明了可能影响整个加丹加盆地的流体流动事件。各相原生流体包裹体中Cu、Co、Ba、Zn、Pb相对Na含量较高，表明成矿作用不局限于离散或独特的事件，而是在盆地演化和变形过程中长期处于同一热液成矿系统的作用下。

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引用次数: 0

A novel “green” sample preparation method for portable X-ray fluorescence (pXRF) geochemistry of unconsolidated sediments as compared to traditional laboratory protocols 一种新型的“绿色”样品制备方法，用于便携式x射线荧光（pXRF）松散沉积物的地球化学，与传统的实验室方案相比

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-08 DOI: 10.1016/j.gexplo.2025.107968

Ross D. Knight, Bruce A. Kjarsgaard

Successful geochemical analyses utilizing in-field portable X-ray fluorescence spectrometry (pXRF) of unconsolidated glacial derived sediments is dependent on sample preparation to provide a consistent representation of the material being analysed. This study evaluates a novel, eco-friendly, “green” sample preparation technique – granular convection - for in-field pXRF spectrometry to acquire on-site real time geochemistry. This method eliminates the use of sieves and minimizes valuable in camp resources (time, solvents, brushes, air compressors etc.) by separating grain sizes through simple agitation of dried samples prior to analyses.

Results from granular convection sample preparation followed by pXRF spectrometry are compared with laboratory sample preparation to <0.063 mm size fraction followed by ICP-ES/MS for aqua regia, 4-acid, and lithium metaborate/tetraborate fusion digestions for a ∼33,500 km² remote region of northern Canada. Comparative data are presented as x-y bivariate plots and interpolated regional spatial distribution maps to highlight similarities and differences between sample preparation and analytical methods. This comparison demonstrates that although in-field sample preparation by granular convection and subsequent pXRF analyses are not always as accurate as laboratory preparation methods, they are comparative on the regional scale shown in this paper. This approach enhances analytical efficiency, reduces resource consumption, and supports cost-effective mineral exploration and/or an environmental sampling program.

利用现场便携式x射线荧光光谱法（pXRF）对未固结的冰川衍生沉积物进行成功的地球化学分析取决于样品制备，以提供被分析物质的一致表示。本研究评估了一种新颖、环保、“绿色”的样品制备技术——颗粒对流——用于现场pXRF光谱分析，以获取现场实时地球化学信息。这种方法消除了筛子的使用，并最大限度地减少了宝贵的资源（时间，溶剂，刷子，空气压缩机等），通过在分析前简单搅拌干燥样品来分离粒度。在加拿大北部约33,500平方公里的偏远地区，颗粒对流样品制备和pXRF光谱分析的结果与实验室样品制备的结果进行了比较，样品制备为<；0.063 mm大小的馏分，然后使用ICP-ES/MS对王水、4-酸和偏硼酸锂/四硼酸锂进行融合消解。比较数据以x-y二元图和插值的区域空间分布图的形式呈现，以突出样品制备和分析方法之间的异同。这一对比表明，尽管颗粒对流的现场样品制备和随后的pXRF分析并不总是像实验室制备方法那样准确，但它们在本文所示的区域尺度上具有可比性。这种方法提高了分析效率，减少了资源消耗，并支持具有成本效益的矿产勘探和/或环境采样程序。

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引用次数: 0

Superimposed Triassic epithermal Au(–Zn) mineralization in the Tongshan Mining Area, Northeast China: Insights from geology, muscovite Rb–Sr geochronology and trace elements in sulfides 铜山矿区三叠纪浅成热液型金（锌）成矿作用：来自地质、白云母Rb-Sr年代学和硫化物微量元素的启示

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-08 DOI: 10.1016/j.gexplo.2026.107976

Chenglin Bai , Guiqing Xie , Xiaolin Wu , Jie Chen , Tianqi Wang

The Tongshan deposit in Northeast China is an overprinted mineral system, featuring Ordovician porphyry Cu mineralization overlain by later Au(–Zn) veins. However, the genetic relationship between these two mineralization events and the timing and ore-forming mechanism of the Au(–Zn) mineralization remain poorly constrained. To address these issues, we conducted detailed paragenetic analysis, TIMA mineral mapping, in situ muscovite Rb–Sr dating, and LA–ICP–MS trace element analysis of pyrite and sphalerite from the Au(–Zn) ore zones. Our results define four hydrothermal stages (I–IV), with gold-bearing minerals occurring in Stage II quartz–polymetallic sulfide veins and Stage III carbonate–fine grained pyrite–Pb–Zn sulfide ± quartz veins with quartz–illite ± pyrite (QIP) alteration halos. The Rb–Sr dating of muscovite from Stages II and III yields an age of 223.9 ± 5.7 Ma (n = 27, MSWD = 1.27), which is significantly younger than the published ~475 Ma porphyry Cu mineralization. Textural and geochemical analyses, as well as a principal component analysis (PCA) of elements, demonstrate that Co–Ni-rich Py1 is a potential gold reservoir for subsequent hydrothermal stages. Additionally, Au enrichment is coupled with As-rich Py2 core–rim textures and Py3 oscillatory zoning, consistent with fluid boiling or rapid near-surface depressurization. Sphalerite geochemistry (depleted in Ga, Ge, In; enriched in Mn, Fe, Cu, Sn) and GGIMFis thermometry (241–312 °C) support a medium–low temperature epithermal environment. Consequently, we propose that Tongshan constitutes an example of a Triassic epithermal Au(–Zn) system superimposed on an Ordovician porphyry Cu deposit. The genetic model elucidates the Au(–Zn) mineralization processes and provides new insights into the exploration of Au and Cu resources in the ore field.

东北铜山矿床是一个奥陶系斑岩型铜矿床，其上覆有后期金（锌）脉。然而，这两个成矿事件与Au（-Zn）成矿的时间和成矿机制之间的成因关系仍不清楚。为了解决这些问题，我们对Au（-Zn）矿带的黄铁矿和闪锌矿进行了详细的共生分析、TIMA矿物填图、原位白云母Rb-Sr测年和LA-ICP-MS微量元素分析。研究结果确定了4个热液阶段（1 - 4），含金矿物赋存于第2阶段石英-多金属硫化物脉中，第3阶段碳酸盐-细晶黄铁矿-铅锌硫化物±石英脉中，伴有石英-伊利石±黄铁矿蚀变晕。第二阶段和第三阶段白云母的Rb-Sr年龄为223.9±5.7 Ma (n = 27, MSWD = 1.27)，明显低于已发表的~475 Ma斑岩铜成矿年龄。元素的结构分析、地球化学分析和主成分分析表明，Py1是一个潜在的热液期金矿床。此外，金的富集与富砷的Py2核缘结构和Py3振荡带相耦合，与流体沸腾或近地表快速降压相一致。闪锌矿地球化学特征（贫Ga、Ge、in，富Mn、Fe、Cu、Sn）和GGIMFis测温（241 ~ 312℃）支持中低温浅成热液环境。因此，我们认为铜山是一个与奥陶系斑岩型铜矿床叠加的三叠系浅成热液型金（锌）体系。该成矿模式阐明了金（锌）矿化过程，为矿区金、铜资源勘查提供了新的思路。

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引用次数: 0

Metal-rich todorokite as a pathfinder mineral in base and precious metal deposits: A mineralogical and microchemical approach to ore exploration 富金属todorokite作为基础和贵金属矿床的探路者矿物：矿物学和微化学的找矿方法

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-08 DOI: 10.1016/j.gexplo.2026.107973

Georgios Soulamidis , Christina Stouraiti , Panagiotis Voudouris , Jean Cauzid , Harilaos Tsikos , Marjolene Jatteau , Paul R.D. Mason , Alexandre Tarantola

Todorokite is a unique tunnel-structured hydrous manganese oxide common in terrestrial manganese deposits. It is renowned for its excellent adsorption capacity, associated with a high specific surface area and microporous structure. Due to its role in metal accumulation in the oxidation zone of some ore bodies, todorokite may act as a vectoring tool for concealed ore deposits. This research uses a multi-method analytical approach to investigate the mineral chemistry of todorokite-rich samples from six hydrothermal deposits in different geological settings in Greece: Mavro Xylo-Karposluk (Drama), Aspro gialoudi-Vani (Milos Island), Piavitsa (Chalkidiki), Trikorfo (Thasos Island), Thapsana (Paros Island), and Koskina (Evia Island). Portable X-ray fluorescence (pXRF) was used as the primary analytical method of various Mn-ore samples, complemented by XRD, SEM and electron microprobe analysis (EMPA) for mineral characterization and finally, micro-XRF and inductively coupled plasma – mass spectrometry (ICP-MS) to determine the concentration and distribution of economically important metals(loids) such as Zn, Pb, Ag, and Sb. In this research, we demonstrate that todorokite from manganese oxide deposits adjacent to intrusion related (Piavitsa, Mavro Xylo-Karposluk) and hybrid epithermal-VMS deposits (Milos Island) shows significant enrichment in Zn, Pb, Ag, As and Sb, in contrast to samples from less mineralized settings (Trikorfo, Thapsana, Koskina) that are base and precious metal-poor. EMPA cross-sections across mineral boundaries and micro-XRF mapping confirm metal zonation and phase-specific enrichment, particularly in Ag- and Zn-bearing todorokite. Additionally, geochemical correlations between pXRF and bulk ICP-MS data of Mn-oxide ore samples highlight the value of portable XRF as a rapid tool for detecting metal anomalies in the field. This research shows that combining portable XRF with focused mineralogical analyses can significantly improve geochemical exploration of hypogene hydrothermal and concealed deposits of base and precious metals.

todoroite是陆相锰矿中常见的一种独特的隧道状含水氧化锰矿。它以其优异的吸附能力，高比表面积和微孔结构而闻名。由于其在某些矿体氧化带中对金属的富集作用，todoroite可能成为隐伏矿床的矢量工具。本研究采用多方法分析方法，研究了希腊6个不同地质环境的热液矿床富含todorokite样品的矿物化学成分：Mavro Xylo-Karposluk （Drama）、Aspro gialoudi-Vani （Milos岛）、Piavitsa （Chalkidiki）、Trikorfo （Thasos岛）、Thapsana （Paros岛）和Koskina （Evia岛）。采用便携式x射线荧光（pXRF）作为各种锰矿样品的主要分析方法，辅之以XRD、SEM和电子探针分析（EMPA）进行矿物表征，最后采用微型x射线荧光（micro-XRF）和电感耦合等离子体质谱（ICP-MS）测定Zn、Pb、Ag、Sb等具有重要经济意义的金属（类）的浓度和分布。研究表明，与侵入相关的锰氧化物矿床（Piavitsa, Mavro Xylo-Karposluk）和混合型热液- vms矿床（Milos Island）中的todorolote矿明显富集Zn、Pb、Ag、As和Sb，而来自矿化程度较低的环境（Trikorfo, Thapsana, Koskina）中的样品则缺乏碱性和贵金属。跨矿物边界的EMPA横截面和微xrf测图证实了金属分带和特定阶段的富集，特别是在含银和含锌的todoroite中。此外，pXRF与锰氧化物矿石样品的大量ICP-MS数据之间的地球化学相关性突出了便携式XRF作为现场检测金属异常的快速工具的价值。研究表明，便携式XRF与重点矿物学分析相结合，可以显著提高地下热液和隐伏碱、贵金属矿床的地球化学勘查水平。

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引用次数: 0

Timing and genesis of gold mineralization in the Kibaran Metallogenic Province, D.R. Congo: Constraints from zircon UPb geochronology, trace element chemistry, and LuHf isotopes 刚果（金）Kibaran成矿省金矿成矿时间和成因：锆石UPb年代学、微量元素化学和LuHf同位素的约束

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-07 DOI: 10.1016/j.gexplo.2026.107972

Rub'son Heritier N'nahano , Huan Li , Mohamed Faisal , Annan Guan , Aye Pyae Phyo , Moise Luemba , Wenbo Sun , Charles Nzolang , Donat Kampata , Raphael Matamba

The Kibaran Metallogenic Province represents a world-class metallogenic system, hosting a diverse array of metal deposits, including significant gold mineralization. Despite its economic importance, the genesis and metallogenic evolution of gold mineralization in this region remain poorly understood. This knowledge gap is primarily due to the absence of comprehensive studies that can provide a coherent genetic model for its formation, making it challenging to contextualize the Kibaran gold deposits within the broader framework of global gold occurrences. In this study, we present new UPb geochronology, trace element chemistry, and LuHf isotopic data from zircons extracted from mafic and intermediate-felsic, and sedimentary rocks to elucidate the geodynamic processes and emplacement mechanisms of gold mineralization in the metallogenic province. Our zircon UPb data reveal two major episodes of gold mineralization: (a) an early Mesoproterozoic event ~1415 Ma associated with the end of Eburnean orogeny, marked by a rift-related magmatic system and dolerite dykes emplacement at Misisi gold field, and (b) a mid-Paleozoic event (~468-333 Ma) linked to the end of Pan-African orogeny, characterized by sedimentation at Misisi and diorite and feldspar porphyry intrusions at Twangiza. LuHf isotopic signatures indicate that both magmatic episodes resulted from partial melting of the older Congo-Ruzizian basement, with juvenile crustal input. Zircon trace element compositions suggest that gold mineralization was generated under high-temperature, oxidizing fluid conditions, with magma migrating from the lower to the upper crust, where it interacted with reduced fluids from carbonaceous country rocks, facilitating gold deposition. These findings suggest that the gold mineralization events in the Kibaran Metallogenic Province coincided with failed rift systems during the breakup of the Columbia and Gondwana supercontinents. This study provides new insights into the temporal relationships between supercontinent cycles and gold mineralization events in the Democratic Republic of Congo.

基巴兰成矿省是一个世界级的成矿系统，拥有各种各样的金属矿床，包括重要的金矿化。尽管具有重要的经济意义，但对该区金矿化成因及成矿演化的认识尚不清楚。这种知识差距主要是由于缺乏全面的研究，无法为其形成提供连贯的遗传模型，因此很难将Kibaran金矿床置于更广泛的全球黄金赋存情况框架内。本文通过对基性、中长英质和沉积岩中提取的锆石进行UPb年代学、微量元素化学和LuHf同位素的研究，阐明了成矿省金矿化的地球动力学过程和侵位机制。我们的锆石UPb数据揭示了两个主要的金矿化时期：(a)与Eburnean造山末期有关的早中元古代事件（~ 1415 Ma），以裂谷相关的岩浆体系和米西西金矿的白云岩岩脉侵位为标志；(b)与泛非造山末期有关的中古生代事件（~468-333 Ma），以米西西的沉积和Twangiza的闪长岩和长石斑岩侵入为特征。LuHf同位素特征表明，这两次岩浆活动都是由较老的刚果-鲁齐济基底部分熔融引起的，并有幼年地壳的输入。锆石微量元素组成表明，金矿成矿发生在高温氧化流体条件下，岩浆由下地壳向上地壳迁移，并与碳质围岩还原流体相互作用，有利于金的沉积。这些发现表明，基巴兰成矿省的金矿化事件与哥伦比亚和冈瓦纳超大陆分裂期间的断裂系统失败相吻合。本研究为研究刚果民主共和国超大陆旋回与金矿化事件的时间关系提供了新的认识。

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引用次数: 0

Tracing molybdenum mineralization through hydrothermal biotite geochemistry in the Jinduicheng porphyry deposit, East Qinling, China 东秦岭金堆城斑岩矿床热液黑云母地球化学示踪钼矿化

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-07 DOI: 10.1016/j.gexplo.2026.107974

Zhenyu Qin , Fan Yang , Xiaoyu Ge , Leon Bagas , Zhaoyue Ding , Luyang Wang , Lifeng Xu

Porphyry deposits are major sources of molybdenum (Mo) and are closely linked to subduction- and collision-related tectonic settings. The transport and deposition of Mo from aqueous fluids are governed by changes in physicochemical conditions, which are recorded in the geochemistry of hydrothermal minerals. The Jinduicheng Mo deposit, located in the East Qinling Orogen of central China, is a giant Mo resource hosted in granitic and andesitic porphyries. Despite previous studies focus on its origin, the detailed mechanisms of hydrothermal mineralization, along with Mo transport and enrichment remain poorly understood. Hydrothermal biotite, which is commonly associated with Mo deposition in porphyry systems, provides valuable insights into ore-forming processes. This study investigates the major and trace element compositions of hydrothermal biotite from the Jinduicheng deposit to constrain the physicochemical conditions and reveal the evolution of the hydrothermal system. The studied biotite is classified as Mg-rich and crystallized at temperatures of approximately 229–331 °C, recording the thermal conditions of the main Mo precipitation stage. Its composition reveals consistently high oxygen fugacity, which favored the stability of soluble hexavalent Mo species in the hydrothermal fluids. The calculated intercept values of IV(F), IV(Cl), and IV(F/Cl) range from 1.06 to 1.55, −4.31 to −3.61, and 4.83–5.68, respectively. These yield high log(f_H₂_O/f_HCl) values of 3.71–4.37, low log(f_H2O/f_HF) values of 0.98–1.64, and log(f_HF/f_HCl) values of 0.49–1.64. Halogen fugacity calculations indicate that the hydrothermal fluids were exceptionally enriched in fluorine relative to chlorine, a characteristic that aligns with significant fluorite alteration observed in the deposit. This F-rich signature likely enhanced Mo extraction from the melt and its transport as molybdate complexes (e.g., KHMoO₄ or NaHMoO₄). The precipitation of molybdenite was primarily driven by the cooling of the hydrothermal fluids, which destabilized these complexes. Fluid mixing and pressure fluctuations likely played secondary roles in the formation of Mo-bearing veins. This study demonstrates that hydrothermal biotite geochemistry is a powerful tool for directly quantifying the oxidized, F-rich nature of ore-forming fluids, and for clarifying the dominant role of cooling in triggering Mo deposition in porphyry systems.

斑岩矿床是钼的主要来源，与俯冲和碰撞相关的构造环境密切相关。水热矿物地球化学记录了Mo在水流体中的运移和沉积受物理化学条件变化的控制。金堆城钼矿位于中国中部东秦岭造山带，是一个赋存于花岗质和安山岩斑岩中的巨型钼矿资源。尽管以往的研究集中在其起源上，但热液矿化的详细机制，以及钼的运输和富集仍然知之甚少。热液黑云母通常与斑岩系统中的Mo沉积有关，为成矿过程提供了有价值的见解。本文研究了金堆城热液黑云母的主微量元素组成，以约束热液系统的物理化学条件，揭示热液系统的演化。研究的黑云母被归类为富mg，在229-331℃的温度下结晶，记录了Mo主要析出阶段的热条件。其组成显示出持续的高氧逸度，这有利于热液流体中可溶六价Mo的稳定性。计算出IV(F)、IV（Cl）、IV（F/Cl）的截距值分别为1.06 ~ 1.55、- 4.31 ~ - 3.61、4.83 ~ 5.68。高对数（fH2O/fHCl）值为3.71-4.37，低对数（fH2O/fHF）值为0.98-1.64，对数（fHF/fHCl）值为0.49-1.64。卤素逸度计算表明，热液流体中的氟相对于氯异常富集，这一特征与在矿床中观察到的显著萤石蚀变相一致。这种富f特征可能增强了钼从熔体中的提取及其作为钼酸盐配合物（如KHMoO4或NaHMoO4）的运输。辉钼矿的析出主要受热液冷却的驱动，热液冷却使这些配合物不稳定。流体混合和压力波动可能在含钼矿脉的形成中起次要作用。该研究表明，热液黑云母地球化学是直接量化成矿流体氧化富f性质的有力工具，并阐明了冷却在触发斑岩系统Mo沉积中的主导作用。

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引用次数: 0

Origin, evolution and precipitation mechanism of ore-forming fluids in Jiaojia belt, Jiaodong Peninsula: Insights from trace elements and SFe isotopes of pyrite 胶东半岛焦家带成矿流体的成因、演化及沉淀机制——来自黄铁矿微量元素和SFe同位素的启示

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-06 DOI: 10.1016/j.gexplo.2025.107969

Jinyu Cheng , Lin Yang , Qingfei Wang , Yixin Li , Wen Zhang , Bin Sun , Xue Dong , Shiyu Zhao , Dapeng Li , Kexin Zhao , Hong Wang

Composition and source of ore-forming fluids in Jiaodong gold deposits remain controversial. To address this issue, the mineral parageneses, in situ trace element and sulfur–iron isotope of pyrite in shallow Nanlvxinmu and deep Zhaoxian gold deposits hosted by the Jiaojia Fault were analyzed. Four hydrothermal stages were identified in both two deposits: quartz–pyrite stage (I), quartz–pyrite–native gold stage (II), quartz–pyrite–chalcopyrite–pyrrhotite–galena–sphalerite stage (III), and quartz–calcite–pyrite stage (IV). Fine-coarse and euhedral-subhedral pyrites (Py2) from the gold-bearing stage II display elevated Au (median: 0.10 ppm) and Ag (median: 0.31 ppm) concentrations in contrast to low Au (median: 0.05 ppm) in other stages. The Au-related Py2 from the Nanlvxinmu deposit has δ³⁴S range of 11.0–12.8 ‰ and δ⁵⁶Fe range of 0.30–0.71 ‰, and the δ³⁴S and δ⁵⁶Fe values of Py2 in the Zhaoxian deposit are 11.2–12.5 ‰ and 0.31–0.85 ‰, respectively. The deduced sulfur and iron isotope compositions of initial ore-forming fluids indicate that the ore-forming fluids were derived from the overlying sediments on the subducted slab. The trace elements and SFe isotopes of pyrite suggest that fluid immiscibility is the primary mechanism of gold precipitation. The similar compositions and source of ore-forming fluids at shallow and deep areas of the Jiaojia Fault indicate that the deeper area of the fault zone still has gold mineralization potential.

胶东金矿床成矿流体的组成和来源一直存在争议。为此，对焦家断裂带南绿新木浅部和赵县深部金矿床中黄铁矿的共生矿物、原位微量元素和硫铁同位素进行了分析。两个矿床均确定了4个热液阶段：石英-黄铁矿阶段(I)、石英-黄铁矿-原生金阶段（II）、石英-黄铁矿-磁黄铁矿-方铅矿-闪锌矿阶段（III）和石英-方解石-黄铁矿阶段（IV）。含金阶段ⅱ的细粗黄铁矿和正面体-亚面体黄铁矿（Py2）显示出较高的Au（中值：0.10 ppm）和Ag（中值：0.31 ppm）浓度，而其他阶段的Au浓度较低（中值：0.05 ppm）。南绿新木金矿金相关Py2 δ34S值为11.0 ~ 12.8‰，δ56Fe值为0.30 ~ 0.71‰，赵县金矿金相关Py2 δ34S值为11.2 ~ 12.5‰，δ56Fe值为0.31 ~ 0.85‰。初始成矿流体的硫、铁同位素组成表明成矿流体来源于俯冲板块上覆沉积物。黄铁矿微量元素和SFe同位素表明，流体不混溶是金沉淀的主要机制。焦家断裂带浅部和深部成矿流体组成和来源相似，表明该断裂带深部仍有成矿潜力。

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引用次数: 0

VNIR spectral signatures of chromium-substituted goethite and hematite in Sukinda ultramafic laterites, India: From mineral spectra to spaceborne hyperspectral mapping 印度Sukinda超镁铁质红土中铬取代针铁矿和赤铁矿的近红外光谱特征：从矿物光谱到星载高光谱制图

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-05 DOI: 10.1016/j.gexplo.2025.107970

Raphael J. Baumgartner , Heta M. Lampinen , Yoram Teitler , Mario Iglesias-Martinez , Erick Ramanaidou , Belinda Godel , Carsten Laukamp , Anwesha Nasreen , Sisir K. Mondal , Helen Powell

This study demonstrates, to our knowledge, the first spaceborne hyperspectral attribution of minor-element substitution in natural iron (oxyhydr)oxides, whereby incorporation of Cr into goethite and hematite produces diagnostic spectral features in the visible to near-infrared (VNIR) wavelength region. Hyperspectral satellite imagery of ferruginous laterite over chromitite-bearing ultramafic rocks at Sukinda (Odisha, India) was integrated with field sampling, petrographic and mineralogical characterization, bulk and mineral-scale chemical analyses, and laboratory VNIR spectroscopy supported by Cr-doped synthetic reference materials. Across the weathering profile—from chromitite–serpentinite bedrock upward through saprock–saprolite to ferruginous laterite and duricrust/ferricrete—Cr is strongly partitioned into goethite and hematite, locally reaching concentrations of up to 20 wt% within goethite. Laboratory reflectance spectra of natural and synthetic goethite and hematite materials reveal Cr-induced modifications to a key crystal-field absorption feature (CFA₁) in the ~650–700 nm range, with the band minimum shifting to longer wavelengths as Cr concentration increases. This behaviour supports a two-component model comprising CFA₁-Fe (~655 nm) and CFA₁-Cr (~700 nm), attributed to ligand-field transitions of octahedrally coordinated Fe³⁺ and Cr³⁺, respectively. Equivalent CFA₁ shifts in PRISMA hyperspectral imagery delineate Cr-rich alteration domains, with continuum-subtracted CFA₁ minima ≥685 nm enabling robust discrimination of Cr substitution in iron (oxyhydr)oxides at low, single-digit concentrations (~2 wt% Cr, approximated from synthetic reference materials). These results demonstrate that spaceborne hyperspectral data can resolve Cr enrichment in ferruginous laterites, enabling new applications in mineral exploration, environmental monitoring, and potentially planetary surface investigations.

据我们所知，这项研究首次证明了天然铁（氧合）氧化物中微量元素取代的星载高光谱属性，即将Cr掺入针铁矿和赤铁矿中产生可见至近红外（VNIR）波长区域的诊断光谱特征。在Sukinda (Odisha, India)，将含铬铁矿的超镁质岩石上的含铁红土的高光谱卫星图像与现场采样、岩石学和矿物学特征、块状和矿物尺度的化学分析以及实验室近红外光谱相结合，该光谱由掺铬合成参考物质支持。在整个风化剖面上，从铬铁矿-蛇纹岩基岩向上穿过腐积岩-腐积岩，到含铁的红土岩和硬壳岩/铁长石，铬被强烈地分割成针铁矿和赤铁矿，在针铁矿中局部浓度高达20%。天然和合成针铁矿和赤铁矿材料的实验室反射光谱显示，在~650 ~ 700 nm范围内，Cr诱导的关键晶体场吸收特征（CFA1）发生了变化，随着Cr浓度的增加，最小波段向更长的波长移动。这种行为支持由CFA1-Fe （~ 655nm）和CFA1-Cr （~ 700nm）组成的双组分模型，分别归因于八面体配位Fe3+和Cr3+的配体场跃迁。PRISMA高光谱图像中的等效CFA1位移描绘了富Cr蚀变域，连续减去的CFA1最小值≥685 nm，能够在低一位数浓度（约2 wt% Cr，由合成参考物质近似）的铁（氧）氧化物中识别Cr取代。这些结果表明，星载高光谱数据可以解析含铁红土中的Cr富集，从而在矿产勘探、环境监测以及潜在的行星表面调查中实现新的应用。

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引用次数: 0

Optimizing short-wave infrared (SWIR) indications of alteration minerals for deep mineralization exploration in the Qianchuiliu lode gold deposit, Jiaodong Peninsula 胶东半岛前垂流矿脉金矿床深部成矿找矿蚀变矿物的短波红外指示优化

IF 3.3 2区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Journal of Geochemical Exploration

Pub Date : 2026-01-02 DOI: 10.1016/j.gexplo.2025.107966

Hongtao Zhao , Liuan Duan , Yu Zhang , Xiaomeng Han , Yongjun Shao , Yuanming Pan , Yuzhou Feng , Xu Wang , Shuling Song , Hongjie Shen

The Jiaodong Peninsula is a globally significant region for lode gold deposits, characterized by disseminated-stockwork mineralization and auriferous quartz-sulfide vein, but recently-discovered auriferous carbonate-sulfide vein mineralization exhibits considerable exploration potential. This study investigates the Qianchuiliu carbonate-sulfide vein gold deposit (13.5 t @ 3.02 g/t) in Jiaodong. It is characterized by three mineralization stages: quartz-K-feldspar (Stage I), dolomite-polymetallic sulfide-native gold stage (Stage II, the primary mineralization stage), and quartz-calcite (Stage III). Integrated SWIR spectral analysis and petrographic observations indicate that the Qianchuiliu deposit contains white micas (58.7 %), carbonates (35.1 %), and chlorites (6.1 %) as predominant alteration minerals. The illite crystallinity (IC) value of white micas is spatially associated with gold mineralization, with IC values ≥1.2 serving as a reliable exploration indicator. Conversely, the Al-OH absorption peak wavelength (Pos2200) of white micas shows a weak spatial correlation with orebodies. On this basis, a three-dimensional parameter model identifies the northern zone at depths of −300 to −400 m in the mining area as a priority exploration target. Regional comparisons show differences in white mica spectral parameters among disseminated-stockwork, quartz-sulfide vein, and carbonate-sulfide vein deposits, effectively distinguished using partial least squares discriminant analysis (PLS-DA). The most significant spectral parameter is white mica Pos2200 (VIP > 1.5), reflecting variations in their forming physicochemical conditions such as pH and oxygen fugacity. This study develops a SWIR-based exploration indicator system for carbonate-sulfide vein gold deposits, highlighting the effectiveness of spectral parameters in identifying mineralization and differentiating deposit types.

胶东半岛是全球重要的矿脉金矿床区，以浸染网状金矿化和含金石英-硫化物脉化为特征，但近年来发现的含金碳酸盐-硫化物脉化具有较大的找矿潜力。胶东前垂流碳酸硫化物脉状金矿床（13.5 t @ 3.02 g/t）。成矿阶段分为石英-钾长石阶段（ⅰ期）、白云石-多金属硫化物-原生金阶段（ⅱ期）和石英-方解石阶段（ⅲ期）。综合SWIR光谱分析和岩石学观察表明，前垂柳矿床主要蚀变矿物为白色云母（58.7%）、碳酸盐（35.1%）和绿泥石（6.1%）。白色云母的伊利石结晶度（IC）值与金矿化具有空间相关性，IC值≥1.2可作为可靠的找矿指标。相反，白色云母的Al-OH吸收峰波长（Pos2200）与矿体的空间相关性较弱。在此基础上，建立了三维参数模型，确定了矿区- 300 ~ - 400 m深度的北部带为优先勘探目标。区域对比显示，在浸染网状、石英-硫化物脉状和碳酸盐-硫化物脉状矿床中，白色云母光谱参数存在差异，利用偏最小二乘判别分析（PLS-DA）可以有效区分。最显著的光谱参数是白色云母Pos2200 (VIP > 1.5)，反映了它们形成的物理化学条件如pH和氧逸度的变化。建立了基于swr的碳酸盐-硫化物脉状金矿找矿指标体系，突出了光谱参数在矿化识别和矿床类型分异中的有效性。

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引用次数: 0