Solid Earth Sciences最新文献

{"title":"Volcanogenic massive sulfide (VMS) deposits within the prolonged felsic dominated volcanism of the Africa's Nubian Shield: A systematic review","authors":"Yeman Gebru, Huan Li","doi":"10.1016/j.sesci.2026.100333","DOIUrl":"10.1016/j.sesci.2026.100333","url":null,"abstract":"<div><div>The Nubian Shield in Africa, which spans Ethiopia, Eritrea, Sudan and Egypt, is a world-class Neoproterozoic (∼880–550) belt hosting numerous volcanogenic massive sulfide (VMS) deposits. Despite some studies conducted on individual deposits in these countries, no systematic studies across the entire shield exists, and underexplored VMS deposits are still present. In this review, we integrate geological, mineralogical, geochemical data of the host volcanic rocks, along with metallogenic data from representative VMS deposits in each country. Geochemical data suggest that the host volcanic rocks are mainly bimodal–felsic metavolcanic and volcaniclastic sequences (rhyolite, dacite, basaltic andesite, and basaltic rocks) of calc-alkaline affinity, derived from more evolved magmas in a mature arc-related setting (island-arc and back-arc basin), which are favorable for hosting Kuroko-type VMS mineralization. Across the shield, pyrite, sphalerite, chalcopyrite, and galena were the dominant sulfide mineral assemblages. U–Pb zircon ages of host volcanic rocks range from ∼887–693 Ma (∼887–720 Ma: Eritrea, Sudan & Ethiopia; ∼751–693 Ma: Egypt), which are consistent with VMS mineralization ages (∼790–702 Ma: Eritrea & Sudan; ∼624 Ma: Egypt) from Re–Os dating of primary sulfide minerals, suggesting prolonged hydrothermal activity related to primary VMS mineralization. Mineralization ages follow northward–younging in the same fashion as their host volcanic rocks, in which older rocks record in the southern and central of the shield (Eritrea, Ethiopia & Sudan), and younger in the northern (Egypt), thus, implying their coeval nature to their tectonic-magmatic events. A Cu-Zn-Pb-Au-Ag mineralization style, similar to Kuroko-type, formed at about 232–275 °C (minimum mean temperatures for sphalerite formation in the Egyptian and Eritrean deposits) was observed across the shield. Moreover, the δ34SV-CDT values of +5.44 ‰ and +9.08 ‰ indicate that the sulfur in VMS mineralization was derived from leaching of the underlying host volcanic rocks and thermochemical reduction of seawater sulfate. This range further indicates that the VMS deposits formed in back-arc basin settings. Combining all the evidence together, during the tectono-evolution of the shield (∼880–550 Ma), the shield underwent subduction-related arc magmatism and volcanism that provided the conditions for primary VMS formation. Meanwhile, Tonian arc magmatism (∼887–720 Ma) in Sudan, Ethiopia and Eritrea, and late Tonian to middle Cryogenian (∼751–693 Ma) in Egypt, resulted in a sequence of volcanic and volcaniclastic rocks. Simultaneously, VMS mineralization has deposited between ∼790–702 Ma in Eritrea and Sudan, and ∼624 Ma in Egypt, suggesting that VMS mineralization is genetically contemporaneous with Neoproterozoic arc volcanism during the closure of the Mozambique Ocean and assembly of East Gondwana. Subsequent greenschist-to lower amphibolite-facies metamorphism, extensive shea","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 3","pages":"Article 100333"},"PeriodicalIF":2.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148995073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoenvironmental and tectonic evolution of the Salt Range Formation (Salt Range, Western Himalayas, Pakistan): Inference from geochemical characteristics","authors":"Waseem Khan ,&nbsp;Wang Licheng ,&nbsp;Salman Ahmed Khattak ,&nbsp;Malik Muhammad Saud Sajid Khan ,&nbsp;Junaid Ur Rehman","doi":"10.1016/j.sesci.2026.100291","DOIUrl":"10.1016/j.sesci.2026.100291","url":null,"abstract":"<div><div>The Salt Range Formation (SRF) of the western Himalaya in Pakistan provides key information about the late Neoproterozoic (terminal Ediacaran) period, offering clues for understanding the paleoclimate, origin, and tectonic evolution of the northwestern Indian margin, that has not been thoroughly studied. This study integrates field observations and geochemical analyses from six representative stratigraphic sections across the Salt Range, Pakistan. The sandstones of the SRF are compositionally immature, indicated by their SiO₂ and Al₂O₃ contents, ranging from 44.36 to 61.35 wt.% (average 53.75 wt.%) and 11.7–19.42 wt.% (average 14.46 wt.%), respectively. The Cr/Th ratios (range 3.09–25.52; average 7.02) suggests that the provenance is dominantly influenced by felsic to intermediate continental rocks, with a minor mafic component and limited sedimentary recycling. Weathering indices, including PIA (46.13–98.14 average 78.73) and CIA (45.61–75.89, average 60.24), indicate moderate chemical weathering under semiarid climatic conditions, consistent with evaporite deposition in arid to semiarid environments. The provenance data suggest that the source terrains were relatively proximal, indicating sedimentation in an active tectonic setting. Tectonic reconstructions point to deposition along an evolving active continental margin, which progressively transitioned toward continental collision. This finding sharply contrasts with the traditionally held view of a terminal-Ediacaran passive margin along the northwestern margin of the Indian Plate. Collectively, these finding provide significant new constraints on sediment dispersal, paleoclimate evolution, and tectonic reorganization in northern Gondwana during this pivotal interval in Earth's history.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 2","pages":"Article 100291"},"PeriodicalIF":2.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Control of mechanical stratification on stress localization in a shallow magma plumbing system containing a pre-existing fracture: Findings from thermo-mechanical, visco-plastic models","authors":"Pallab Jyoti Hazarika ,&nbsp;Amiya Baruah ,&nbsp;Ritabrata Dasgupta ,&nbsp;Nibir Mandal","doi":"10.1016/j.sesci.2026.100292","DOIUrl":"10.1016/j.sesci.2026.100292","url":null,"abstract":"<div><div>Shallow magma chamber hosted in mechanically heterogeneous crustal segments often contain pre-existing fracture (PEF), which can influence the nucleation and growth of dikes due to magma excess pressure (<em>P</em>_<em>e</em>). Employing thermo-mechanical finite element models using visco-plastic rheology, this study investigates how <em>P</em>_<em>e</em> and competency contrast (<em>C</em>_<em>r</em>) between the crustal layers control stress localization, yield strength distribution, and ground displacement for different chamber temperatures (<em>T</em>_<em>c</em>). We show that condition with higher <em>P</em>_<em>e</em> and <em>C</em>_<em>r</em>, enhance tensile stress localization around the chamber flanks and near PEF tips, amplifying mechanical interaction between such zones. FE model results obtained with high <em>C</em>_<em>r</em> (=1:20) condition produce uneven stress distribution between the layers with contrasting stiffness and develops potential zone for dike deflection. This agrees with the analysis of elastic mismatch parameter (<em>α</em>_<em>D</em>), which increases by up to ∼36 % when <em>C</em>_<em>r</em> is increased from 1:5 to 1:20. PEF lowers the yield strength near the chamber tip and along the chamber-facing side of the PEF, and such low yield zones widen progressively with increasing <em>P</em>_<em>e</em> and <em>C</em>_<em>r</em>. We show that vertical ground displacements amplify with increasing <em>T</em>_<em>c</em> and <em>P</em>_<em>e</em>, which hold an inverse relation with <em>C</em>_<em>r</em>. Calculated stored strain energy (<em>U</em>_<em>0</em>) from the model results are utilized to evaluate the strike dimensions of feeder dikes, showing an increasing trend with an increase in <em>P</em>_<em>e</em>. Finally, we present a comparison between the modelled ground displacements and observations from the Campi Flegrei caldera (Italy), which shows a good agreement between the modelled and natural surface uplift magnitudes.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 2","pages":"Article 100292"},"PeriodicalIF":2.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry and Sr-Nd-Pb isotope systematics of Pleistocene Adakites at Los Espinos Volcano (Mexico) and implications for the volcanic plumbing system of a small-volume volcano","authors":"Boris Chako-Tchamabé ,&nbsp;Bodo Weber ,&nbsp;Jhoanna Silis-Esquivel ,&nbsp;Ana Teresa Mendoza Rosas ,&nbsp;Merlin Gountié Dedzo ,&nbsp;Eric Martial Fozing","doi":"10.1016/j.sesci.2026.100290","DOIUrl":"10.1016/j.sesci.2026.100290","url":null,"abstract":"<div><div>This research investigates the origin and relationship between adakites and non-adakitic magmas found at Los Espinos Volcano (LEV), situated within the Michoacán-Guanajuato Volcanic Field (MGVF) in Mexico. LEV consists of a younger phreatomagmatic tuff cone (LETC) with adakitic features, overlaying two pre-tuff cone units (PTC) made of a lava flow and a scoria cone remnant, both of calc-alkaline composition. The primary objective is to assess whether the shift from calc-alkaline to adakitic compositions results from the development of a crustal magma reservoir beneath the volcano or from broader tectonic processes, such as crustal thickening during the late Miocene to Quaternary periods. The findings indicate that the magmatic source for the PTC and LETC is a metasomatized mantle wedge. High Sr/Y ratios (&gt;40), La/Yb values (7.2–9.9), and Mg# (33–35), along with the isotopic signatures (⁸⁷Sr/⁸⁶Sr: 0.70335–0.70415; ¹⁴³Nd/¹⁴⁴Nd: 0.51278–0.51299; ²⁰⁶Pb/²⁰⁴Pb: 18.508–18.666; ²⁰⁷Pb/²⁰⁴Pb: 15.510–15.559; ²⁰⁸Pb/²⁰⁴Pb: 38.109–38.321) collectively support the interpretation that the adakitic magmas were generated through the mixing between the early calc-alkaline magma and melted lower crust, previously metamorphosed to granulite facies possibly through sustained magmatic underplating and thermal metamorphism from ongoing basaltic magma influx at the base of the crust. The temporal and compositional variations observed in the erupted products indicate that LEV experienced multiple eruptive events, with a significant repose period between the PTC and LETC activities, highlighting the complexity and possible polygenetic nature of this small-volume volcano.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 2","pages":"Article 100290"},"PeriodicalIF":2.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear error propagation and Monte Carlo simulation for MC-ICP-MS neodymium isotope ratios uncertainty analysis","authors":"Tianyu Zhang ,&nbsp;Qichao Yang ,&nbsp;Haiou Gu ,&nbsp;Dongyong Li","doi":"10.1016/j.sesci.2026.100287","DOIUrl":"10.1016/j.sesci.2026.100287","url":null,"abstract":"<div><div>This study presents a comprehensive framework for uncertainty estimation in Nd isotope ratio analysis using both linear error propagation and Monte Carlo simulation. The developed model explicitly incorporates uncertainties from key analytical procedures—including baseline subtraction, isobaric interference correction, and exponential law mass fractionation normalization—providing more accurate theoretical precision limits. For the internally normalized ¹⁴³Nd/¹⁴⁴Nd ratio, predicted cycle-level uncertainties show excellent agreement with measured values, validating the accuracy of both approaches. Evaluation of two interference correction strategies—the natural ¹⁴⁷Sm/¹⁴⁴Sm ratio method and the iterative method—reveals that both yield comparable uncertainties when ¹⁴⁷Sm/¹⁴⁴Nd is below ∼5 × 10⁻³. Uncertainty in Nd isotope ratios exhibits a strong inverse dependence on beam intensity, with Johnson noise dominating below a ¹⁴⁴Nd intensity threshold of ∼0.2 V and counting statistics prevailing at higher intensities. This threshold offers a clear criterion for selecting a 10¹³ Ω amplifier resistor to improve precision in low-signal regimes. Furthermore, baseline correction is shown to introduce Johnson noise derived uncertainty, with a more pronounced effect at lower beam intensities; our results provide specific guidance on baseline cycle number needed to control this contribution under different signal conditions. Monte Carlo simulations demonstrate robust performance when using at least 5 × 10⁴ cycles per simulation, achieving results within 1 % of linear propagation estimates while maintaining computational efficiency (∼1.5 s/simulation). External reproducibility is primarily governed by Johnson noise and counting statistics, with secondary factors such as mass bias variations in the mass spectrometer contributing ∼10 % to the total measured external uncertainty. Finally, we demonstrate that diluting sample solution increases analytical uncertainty, especially at lower sample amounts, despite longer measurement times, whereas concentrating sample solution improves precision provided sample consumption during signal stabilization is accounted for. These findings provide a practical foundation for optimizing precision in Nd isotope analysis via uncertainty model based experimental design.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100287"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metallogenic potential and prospecting of orogenic gold deposits in the Shuihouling area of the Dabie Orogenic Belt: A geochemical evidence from stream sediment anomalies","authors":"Xiandong Luo ,&nbsp;Lei Chen ,&nbsp;Jinlai Tang ,&nbsp;Xiaoyong Yang","doi":"10.1016/j.sesci.2025.100278","DOIUrl":"10.1016/j.sesci.2025.100278","url":null,"abstract":"<div><div>The Shuihouling ductile shear zone, located in the core of the Dabie Orogenic Belt spanning Anhui and Hubei provinces, is a key structural unit with notable mineral potential. Situated within the Wudang-Tongbai-Dabie Mo-REE-Au-Ag-Pb-Zn polymetallic belt, it shows promising prospecting potential, particularly for gold exploration. Our 1:50,000 stream sediment survey identified three major composite anomalies in the Shuihouling area, each with distinct elemental concentration centers and strong anomaly correlations. After verification, all three were classified as mineral-induced B2 anomalies: The HS-01 anomaly, controlled by a fault zone, is linked to gold-polymetallic mineralization; the HS-02 anomaly, controlled by the ductile shear zone, is associated with copper-molybdenum polymetallic mineralization; and the HS-03 anomaly, in S-type granitic gneiss, shows copper-gold mineralization with significant concentrations of copper (19.41 %) and gold (1.41 g/t), indicating strong deep mineralization potential. The HS-03 anomaly also suggests a combined effect of polymetallic and molybdenum mineralization bodies. The discovery of these gold and copper anomalies highlights significant potential for ductile shear zone-type gold deposits in the Shuihouling area, providing crucial insights for future gold exploration and mineralization studies in the Dabie Orogenic Belt. These geochemical anomalies serve as important markers for guiding future exploration efforts, and their significance for understanding mineralization mechanisms in this region cannot be overstated.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100278"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot topics in deep-sea sciences","authors":"Weidong Sun,&nbsp;Hongli Zhu","doi":"10.1016/j.sesci.2025.100286","DOIUrl":"10.1016/j.sesci.2025.100286","url":null,"abstract":"","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100286"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrocarbon generation potential, palynofacies examination and 1D basin modeling of the Middle Jurassic–Lowermost Cretaceous intervals, Mesopotamian Foredeep Basin, Iraq","authors":"Abbas F. Gharib ,&nbsp;Iman M. Anwer ,&nbsp;Mohammed Y. Najmuldeen ,&nbsp;Ali Saaduldeen Abbas","doi":"10.1016/j.sesci.2026.100288","DOIUrl":"10.1016/j.sesci.2026.100288","url":null,"abstract":"<div><div>This study evaluates hydrocarbon generation, palynofacies, and burial-thermal evolution of Middle Jurassic-Lowermost Cretaceous source rocks in the Ajeel Field, located in the Mesopotamian Foredeep Basin of Iraq. Through Rock-Eval pyrolysis, Total organic carbon (TOC) analysis, and palynofacies, a comprehensive investigation of 109 core and cutting samples in wells 8 and 12 was supported by one-dimensional (1D) basin modeling. The geochemical data show a TOC maximum of 23.0 wt.%, with reported mean concentrations of 6.22 wt.% in the Sargelu Formation and 10.09 wt.% in the Naokelekan Formation. The Chia Gara Formation bears a broad range of TOC values, as shown by the heterogeneous depositional environment. Hydrogen Index (HI) values reach 457 mg HC/g TOC, indicating dominance of oil-prone Type II kerogen, particularly in the Naokelekan and Chia Gara formations, and with minor Type II/III kerogen content in the Sargelu Formation interval. The calculated Tmax (428–448 °C) plus the estimated vitrinite reflectance (% Ro: 0.53–0.85 %) can define the maturity range that is characterized by early and peak oil window maturities. Palynofacies data confirm the deposition in suboxic–anoxic environments on the marine shelf, and amorphous organic matter (AOM) varies widely between 1 and 98 %. This has been confirmed as the Bajocian-Berriasian age and marine provenance as demonstrated by the presence of diagnostic palynomorphs. Basin modeling shows that hydrocarbons originated in the Oligocene (∼27 Ma) and were expelled during the Miocene (21-15 Ma). This is also supported by the higher transformation ratio (%TR) values, which reached up to 83 % for Sargelu, up to 70 % for Naokelekan Formation, and up to 50 % for the Chia Gara Formation. These findings confirm the identified formations as the main oil-producing horizons in the basin and emphasize their significance as potential oil exploration activities in northern Iraq.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100288"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Domain adaptation of large language models for geotechnical applications","authors":"Lei Fan ,&nbsp;Fangxue Liu ,&nbsp;Cheng Chen","doi":"10.1016/j.sesci.2025.100285","DOIUrl":"10.1016/j.sesci.2025.100285","url":null,"abstract":"<div><div>The rapid advancement of large language models (LLMs) is transforming opportunities in geotechnical engineering, where workflows rely on complex, text-rich data. While general-purpose LLMs demonstrate strong reasoning capabilities, their effectiveness in geotechnical applications is constrained by limited exposure to specialized terminology and domain logic. Thus, domain adaptation, tailoring general LLMs for geotechnical use, has become essential. This paper presents the first review of LLM adaptation and application in geotechnical contexts. It critically examines four key adaptation strategies, including prompt engineering, retrieval-augmented generation, domain-adaptive pretraining, and fine-tuning, and evaluates their comparative benefits, limitations, and implementation trends. This review synthesizes current applications spanning geological interpretation, subsurface characterization, design analysis, numerical modeling, risk assessment, and geotechnical education. Findings show that domain-adapted LLMs substantially improve reasoning accuracy, automation, and interpretability, yet remain limited by data scarcity, validation challenges, and explainability concerns. Future research directions are also suggested. This review establishes a critical foundation for developing geotechnically literate LLMs and guides researchers and practitioners in advancing the digital transformation of geotechnical engineering.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100285"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biotite composition constrains Tongling skarn Cu–Au mineralization, eastern China","authors":"Sujuan Zhou,&nbsp;Qian Feng,&nbsp;Liu Yang,&nbsp;Quanzhong Li,&nbsp;Jun Yan,&nbsp;Qiaoqin Xie,&nbsp;Xiaochun Xu,&nbsp;Jiancheng Xie","doi":"10.1016/j.sesci.2026.100289","DOIUrl":"10.1016/j.sesci.2026.100289","url":null,"abstract":"<div><div>Skarn Cu, Au deposits are most important deposit-type in the Tongling region, eastern China, where skarn Au deposits are closely associated with pyroxene monzodiorite, and skarn Cu deposits are genetically related to quartz monzodiorite and granodiorite. However, the causes on the Tongling skarn Cu and Au mineralization differences remain poorly constrained. This study systematically presents petrographic, mineralogical, in-situ geochemical analyses of primary magmatic biotite from the Tongling skarn Cu and Au deposits. Biotite from the pyroxene monzodiorite has higher FeO, TiO₂, F and Cl contents, and lower SiO₂, MgO and MnO contents than that in the quartz monzodiorite and granodiorite. Compared with the quartz monzodiorite and granodiorite, biotite in the pyroxene monzodiorite exhibits lower Rb–Co–Ni–Cs but higher Nb–Ta–Li contents. Moreover, the content of total rare earth elements (REE) in biotite decreases from the pyroxene monzodiorite to quartz monzodiorite and then to granodiorite. These element variations are consistent with the magma fractionation trend. A slightly correlation of Rb content with Cu and Au contents in biotite from the pyroxene monzodiorite to the quartz monzodiorite and granodiorite suggests that magma fractionation is critical to Cu, Au mineralization in the Tongling region. The higher biotite IV(F) and IV(Cl) values of the granodiorite than the pyroxene monzodiorite indicate F and Cl depletion during the fractional crystallization, which may be caused by fluid exsolution. The lower biotite log (<em>f</em> HF/<em>f</em> HCl) values (−2.26 to −1.88, avg. −2.07) of the granodiorite than the pyroxene monzodiorite (−2.09 to −1.71, avg. −1.91) indicate more Cl-enriched fluid in the granodiorite. Therefore, we inferred that the differences of Cu and Au mineralization in the Tongling region are probably magma fractionation process, halogen fugacity in magma or fluid, and Cl-enriched degree of fluid.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"11 1","pages":"Article 100289"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}