Acta Geochimica最新文献

{"title":"Simulating reaction-kinetic distributions across a range of activation energies and frequency factors with relevance to shale exploitation","authors":"David A. Wood","doi":"10.1007/s11631-026-00862-6","DOIUrl":"10.1007/s11631-026-00862-6","url":null,"abstract":"<div><p>Pyrolysis curves representing product quantities generated from shale and coal samples subjected to stepped heating ramps can be simulated by combinations of first-order Arrhenius reactions. The simulated curves closely match those of shales when using Arrhenius-equation integrals of activation energies (<i>E</i>) and frequency factors (<i>A</i>) allowed to vary along the trend <i>E</i> = 5.479<i>lnA</i>-119.283. 1928 simulations are evaluated for 6 distinctive heating ramps. The reaction distributions in those simulations are centred at <i>E</i> values between 105 and 345 kJ/mol with the peak <i>E</i> values varying by 1 kJ/mol for the simulated pyrolysis responses (referred to as simulated pyrograms) and cumulate transformation-factor (<i>∑TF</i>) curves, are compared to reaction-kinetic distributions fitted to the multiple-heating-rate recorded pyrolysis responses (referred to as recorded pyrograms) of real shale samples. The differences between the S2-peak temperatures generated by two different heating ramps and the peak <i>E</i> values of the kinetic distributions show good agreement between the simulated and real shale reaction-kinetic <i>A-E</i> values. However, the temperature differences between different <i>∑TF</i> fractions are substantially greater for real shales compared to the simulated reaction-kinetic distributions, making them less useful for <i>E-A</i> prediction purposes. The involvement of bitumen and kerogen reaction residues in real shales as well as unreacted kerogen of multiple compositions is the most likely explanation for such differences. The <i>E</i> and <i>A</i> weighted-mean and weighted-standard-deviation values of the reaction distributions fitted to recorded shale pyrograms are useful metrics to characterize and distinguish shale samples. These values identify appropriate shale samples to derive reaction kinetics for basin modelling to establish the temperature and timing intervals of petroleum generation. They also assist in identifying shale zones likely to be associated with high resource capacities and micropore developments suitable for gas (CH₄, CO₂, H₂) storage.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 4","pages":"833 - 857"},"PeriodicalIF":1.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782457","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":"Two phases of early Palaeozoic magmatism at the Wude area in the western Bainaimiao arc (Inner Mongolia, China): Petrogenesis and tectonic implications","authors":"Cong Ding,&nbsp;Zhicheng Zhang,&nbsp;Yunxi Meng,&nbsp;Jianzhou Tang,&nbsp;Qi Wang,&nbsp;Huaihui Zhang,&nbsp;Baofu Han","doi":"10.1007/s11631-026-00857-3","DOIUrl":"10.1007/s11631-026-00857-3","url":null,"abstract":"<div><p>Arc magmatism plays a crucial role in constraining the tectonic evolution of orogenic belts. This study focuses on two phases (Phase I and II) of the Early Palaeozoic intrusive rocks in the Wude area, located in the western Bainaimiao arc terrane (BAT), southeastern Central Asian Orogenic Belt. We performed whole-rock geochemistry, zircon U–Pb chronology, and Hf isotope, amphibole geochemical analyses. Phase I comprises granites and quartz diorites with zircon U–Pb age range from 464 to 457 Ma. These rocks are medium- to high-K calc-alkaline, fractionated I-type granites exhibiting an arc-like geochemical signature, such as enrichments in Rb, Ba, Th, U, Pb, and Sr and depletions in Nb, Ta, Ti, and P. Phase II intrusive rocks consist of congeneric hornblendites, diorites, plagioclase porphyrite, and granite porphyry, with zircons U–Pb ages from 446 to 442 Ma and positive ε_Hf(t) values (+ 1.50 to + 13.39). These rocks display island arc magma compositions characterized by enrichments in large-ion lithophile elements (e.g., Ba, U, Pb, and Sr) and depletions in high-field-strength elements (e.g., Nb, Ta, Zr, Hf, and Ti). Amphiboles from the hornblendites and diorites in the Wude area are classified as magnesio-hornblendes, indicating crystallization temperatures of 702.5–763.6 °C, depths of 13.3–19.1 km (based on TiO₂ contents), and REDOX conditions of ΔNNO + 0.52 to 1.55. The positive zircon ε_Hf(t) values and calculated crystallization pressures of 3.09–4.95 Kbar (13.3–19.1 km) support the formation of cumulate hornblendites and diorites in a juvenile island arc setting within the middle crust. These findings provide insights into the tectonic and paleogeographic evolution of the western Bainaimiao Arc during the Early Palaeozoic. Geochronological and geochemical data suggest a tectonic transition occurred between Phase I and Phase II. Based on the age of the ophiolitic mélange and previous works, this transition may reflect a shift from a south-dipping subduction of the Paleo-Asian Ocean to a north-dipping subduction of the southern Bainaimiao Ocean.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 3","pages":"467 - 488"},"PeriodicalIF":1.3,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196330","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":"The formation of orebodies controlled by thrust faults is driven by mechanical mechanisms in the Maoping lead–zinc deposit within the Sichuan-Yunnan-Guizhou Pb–Zn polymetallic metallogenic area","authors":"Jianbiao Wu,&nbsp;Runsheng Han,&nbsp;Hongsheng Gong,&nbsp;Shunchuan Wu,&nbsp;Yan Zhang,&nbsp;Yanhong Liu","doi":"10.1007/s11631-026-00854-6","DOIUrl":"10.1007/s11631-026-00854-6","url":null,"abstract":"<div><p>In hydrothermal ore deposits, thrust faults are a common type of ore-controlling structure, yet understanding of the formation and distribution of the orebodies under their control remains elusive. The Maoping lead–zinc deposit, located in the Sichuan-Yunnan-Guizhou Pb–Zn polymetallic metallogenic province, is a representative deposit in which orebodies are controlled by interlayer faults. To address the issues of orebody extension and thickness control mechanisms for this type of deposit in the region, this paper employs the Theory and Methods of Orefield Geomechanics to study the mathematical and physical relationships underpinning the extension and true thickness of orebodies and to analyse the mechanical mechanism that determines their dip angles. Our research indicates that the smaller the angle between the thrust fault and the lower-sequence metallogenic structural planes is, the greater the extension and true thickness of the orebody. Furthermore, the orebody dip is determined by the thrust fault dip and the mechanical mechanism underlying the lower-sequence metallogenic structural planes. Based on this, at the Maoping super-large germanium-rich lead–zinc deposit in northeastern Yunnan, we determine the extension of the I-8 orebody and predict the location of a concealed orebody. This research can be effectively applied to determine the extension and true thickness of known orebodies, predict the location of concealed orebodies, and optimize the exploration engineering layout for other hydrothermal deposits controlled by thrust faults.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 5","pages":"1493 - 1512"},"PeriodicalIF":1.4,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098129","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":"Tracing the petrogenesis of fossil magma reservoirs using enclaves in the Damavand stratovolcano, northern Iran","authors":"Mohsen Zadsaleh,&nbsp;Hamed Pourkhorsandi,&nbsp;Vinciane Debaille,&nbsp;Jeroen de Jong,&nbsp;Karen Fontijn,&nbsp;Fariborz Masoudi","doi":"10.1007/s11631-026-00853-7","DOIUrl":"10.1007/s11631-026-00853-7","url":null,"abstract":"<div><p>Damavand stratovolcano is situated within the central Alborz Mountains in northern Iran. Numerous studies have delved into the geodynamics and the factors contributing to the formation of Damavand volcano in the Alborz Mountains. The volcano comprises multiple lava flows and pyroclastic deposits, predominantly consisting of trachyte and trachyandesite. The lava flows often contain enclaves with various lithological compositions like monzonite, monzodiorite and monzogabbro, and these provide valuable insights into the magmatic history and evolution of Damavand volcano. Isotopic data (¹⁴³Nd/¹⁴⁴Nd = 0.512559–0.512623; ⁸⁷Sr/⁸⁶Sr = 0.704745–0.704929; ¹⁷⁶Hf/¹⁷⁷Hf = 0.282722–0.282773) indicate changes in the magma source during volcanic activity, although isotopic compositions of both the enclaves and their host rocks have similar ¹⁴³Nd/¹⁴⁴Nd vs ⁸⁷Sr/⁸⁶Sr values, which lie close of the Bulk Silicate Earth values. Trace elements indicate that Damavand volcano is geochemically adakitic (mainly low-silica adakites). The <i>ε</i>Nd values vs ⁸⁷Sr/⁸⁶Sr isotope ratios for both the enclaves and the host rocks further support the interpretation that these rocks are primarily adakites derived from a thickened lower crust.</p><p>The interpretation of the petrographic, elemental and isotopic data suggests that the enclaves at Damavand volcano did not originate from a single eruption or phase. Instead, these enclaves are fragments of ancient magma reservoirs that crystallized at depth and were later brought to the surface by subsequent eruptions. The <i>ε</i>Nd vs ⁸⁷Sr/⁸⁶Sr isotope ratios further indicate that, as the volcano evolved over time, magma migration occurred from deeper to shallower depths in the Earth’s crust. This trend reflects the changing dynamics of magma generation and movement within the volcanic system, shedding light on the complex evolution of Damavand volcano. By studying these processes, we can gain valuable insights into the magmatic history and behavior of the volcanic systems and their evolution.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 3","pages":"530 - 553"},"PeriodicalIF":1.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196275","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":"Trace element composition and significance of sulfides in the Koktokay No. 3 pegmatite","authors":"Yunlong Liu,&nbsp;Kun Liu","doi":"10.1007/s11631-025-00851-1","DOIUrl":"10.1007/s11631-025-00851-1","url":null,"abstract":"<div><p>The Koktokay pegmatite district in the Altay orogen of Xinjiang is a significant rare metal mineralized cluster in China, hosting the world-renowned Koktokay No. 3 pegmatite vein. This study focuses on sulfides, discovered for the first time in the saccharoidal albite zone (Zone II) of the No. 3 vein. We systematically investigated their mineral assemblages and geochemical characteristics using TIMA (TESCAN Integrated Mineral Analyzer) and LA-ICP-MS in situ trace element analysis to elucidate their formation conditions, origin, and implications. The results indicate that the sulfide assemblage in Zone II is dominated by sphalerite, accompanied by bismuthinite, chalcopyrite, and pyrite. This paragenesis suggests formation under moderate- to high-temperature hydrothermal conditions (~ 340 °C), high sulfur fugacity (log_f_(S_2) &gt; – 11), and a reduced environment. The sphalerite is characterized by enrichment in Fe, Mn, and In, and depletion in Ga, Ge, and Cd. Both trace element discrimination and machine learning analysis consistently confirm a magmatic–hydrothermal origin, crystallizing during the magmatic–hydrothermal transition stage of pegmatite evolution. This study provides the first direct constraint on the thermal state (~ 340 °C) of the Koktokay pegmatite system during the magmatic–hydrothermal transition stage revealing the crucial role of these conditions in facilitating the migration and enrichment of critical metals like Be and the formation of economically significant mineralization. These findings enhance the understanding of the metallogenic processes in the pegmatite-type deposit.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 5","pages":"1320 - 1333"},"PeriodicalIF":1.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098304","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":"Petrogenesis and geodynamic mechanism of Indosinian magmatism in South China Block: Insights from the Neihan–Deqing–Hetai Granitic Belt, western Guangdong","authors":"Jianrong Wang,&nbsp;Zhipeng Xie,&nbsp;Wenchang Li,&nbsp;Chuandong Xue,&nbsp;Lei Dou,&nbsp;Hongwei Zhao,&nbsp;Wei Wang,&nbsp;Xingwang Song","doi":"10.1007/s11631-025-00848-w","DOIUrl":"10.1007/s11631-025-00848-w","url":null,"abstract":"<div><p>The geodynamic mechanism(s) responsible for Indosinian magmatism in the South China Block (SCB) remains controversial. This study examines the Neihan–Deqing–Hetai Granitic Belt in western Guangdong Province, providing new insights through comprehensive petrological and geochemical analyses. The Neihan pluton comprises S-type two-mica granite, characterized by high-temperature mineral assemblages (orthopyroxene, cordierite, garnet). In contrast, the Deqing and Hetai plutons consist mainly of S-type biotite monzogranite and granodiorite with subordinate basic andesite lenses. Thermometric constraints from zircon saturation and Ti–in–zircon thermometry indicate high-temperature crystallization with peak melt temperature exceeding 800 °C. Zircon U–Pb geochronology constrains emplacement at ca. 250 Ma. These granitoids exhibit peraluminous signatures (A/CNK = 0.97–1.27, mean = 1.1), highly fractionation (SiO₂ = 65.9–74.3 wt%, Al₂O₃ = 12.5–16.1 wt%; Differentiation Index = 79.2–95.2), light rare-earth element (LREE) enrichment [(La/Yb)_CN = 3.44–25.0], and pronounced negative Eu anomalies (Eu/Eu* = 0.21–0.63, excluding sample GD09-3 at 1.14). Primitive mantle-normalized patterns show large-ion lithophile elements enrichment (Rb, Th, U, K, Pb) relative to high-field-strength elements (HFSE: Nb, Ta, P, Ti). Isotopic data reveal high ⁸⁷Sr/⁸⁶Sr ratios (0.71812–0.72182), low <i>ε</i>_Nd(<i>t</i>) values (− 9.9 to − 9.1), and Paleoproterozoic model ages (<i>T</i>_2DM = 1.69–1.83 Ga). In situ zircon Hf isotopic analyses yield <i>ε</i>_Hf(t) values between − 15.9 and − 3.2, with two-stage Hf model ages of 1.48–2.28 Ga (mean = 1.78 Ga). Collectively, these data suggest that the granitoids originated from Paleoproterozoic metasedimentary protoliths, with variable contributions from mafic magmas. Basic andesite lenses (SiO₂ = 55.8–56.5 wt%; FeO^T + MgO = 11.2–11.4 wt%) exhibit less evolved isotopic signatures [(⁸⁷Sr/⁸⁶Sr)_I = 0.71112–0.71162; <i>ε</i>_Nd(<i>t</i>) =  − 5.5 to − 5.3)], indicating higher mafic contributions. Comparative analysis with coeval granitoids in the Cathaysia Block, particularly the adjacent Darongshan–Shiwandashan Granitic Belt, supports formation in a compressional regime during SCB–Indochina collision. We propose that collision initiated at the Hainan–Yunkai massif and propagated northwestward along the Ailaoshan–Song Ma suture, generating heterogeneous stresses that caused tearing of the subducting slab. This tearing facilitated asthenospheric upwelling, providing the thermal anomaly driving crustal anatexis and mechanical heterogeneity accounting for the observed magmatic diversity.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 3","pages":"596 - 616"},"PeriodicalIF":1.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196252","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":"Origin of magnetite phenocrysts in mafic magmatic enclaves of the Bamuni pluton, Mikir Massif, Northeast India","authors":"Bibhuti Gogoi,&nbsp;Tribujjal Prakash","doi":"10.1007/s11631-026-00852-8","DOIUrl":"10.1007/s11631-026-00852-8","url":null,"abstract":"<div><p>Magnetite (Fe₃O₄) has been widely documented across igneous and metamorphic scenarios; yet the mechanisms governing its genesis in mafic magmatic enclaves (MMEs) and mixed rocks are inadequately constrained. The current work presents a distinctive effort to elucidate the underlying physicochemical conditions governing magnetite formation in MMEs triggered by magma mixing. Mafic magmatic enclaves are common structures in plutonic environments, and field investigations in the Bamuni Pluton of Mikir Massif, Northeast India, demonstrate mafic-felsic magma interaction, as evidenced by a widespread occurrence of MMEs throughout the pluton. Distinct euhedral magnetite phenocrysts occur within a biotite-rich matrix in the inner part of double-layered MMEs. P-T conditions estimated using biotite compositions show a pressure and temperature range of 3.93–5.89 kbar and 749–767 °C, respectively. These biotite compositions were also used as a parameter to estimate oxygen fugacity (<i>f</i>O₂), and subsequent calculations revealed that their crystallization took place in an oxidizing environment. The calculated log<i>f</i>O₂ values of biotite crystallization range between −9.9 and −9.5. Mafic-felsic magma interaction is evidenced by the presence of different disequilibrium textures, such as quartz ocelli, titanite ocelli, biotite clots, and acicular apatite. Apart from forming disequilibrium textures, magma mixing also facilitates substantial mass transfer leading to the destabilization of existing minerals and formation of new minerals. Subsequent to mafic magma intrusion and formation of MMEs in the studied pluton, precursor clinopyroxene possibly destabilized to amphibole. Further interaction between both the mafic and felsic magmas led to the diffusion of K₂O from the felsic to mafic domain. An increase in K₂O concentration in the mafic domain thereby caused the breakdown of amphibole to biotite, indicating an advanced hybridization stage. Liberation of FeO during the transformation of amphibole to biotite subsequently contributed to the formation of magnetite in the MMEs under oxidizing conditions.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 3","pages":"489 - 505"},"PeriodicalIF":1.3,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196331","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":"Rare earth elements and C and O isotope compositions of modern lake Fe–Mn nodules from Lake Krasnoe, Karelian Isthmus, North-West Russia","authors":"Vladimir N. Kuleshov,&nbsp;Andrey Yu. Bychkov,&nbsp;Irina Yu. Nikolaeva","doi":"10.1007/s11631-025-00850-2","DOIUrl":"10.1007/s11631-025-00850-2","url":null,"abstract":"<div><p>Rare earth elements (REEs) were studied in ferromanganese nodules and bivalve shell carbonates from Lake Krasnoe (Karelian Isthmus, West Russia). This lake is a model example of modern lacustrine manganese ore genesis. The results revealed important features of the formation of modern manganese ores in the diagenesis zone of lake sediments: (1) carbonates of bivalve shells and the Mn-oxide crusts on them show very strong positive Eu anomalies but insignificant negative Ce anomalies; (2) manganese oxide nodules exhibit strong negative Eu anomalies; therefore, the negative cerium anomalies are insufficient; (3) REEs in the studied Fe–Mn-ore nodules are associated with organic matter (C_org), phosphates and iron hydroxides; (4) a positive correlation between carbon (<i>δ</i>¹³C, ‰, V-PDB) and oxygen isotopes (<i>δ</i>¹⁸O, ‰; SMOW) versus Ce/Ce* is observed. The authors believe that the obtained regularities in the distribution of REE content, Eu and Ce anomalies, and C- and O-isotope composition (<i>δ</i>¹³C, <i>δ</i>¹⁸O) result from changes in the physicochemical conditions in the ore body lake sediments during early diagenesis, which oxidize organic matter (C_org), and active participation of microorganisms in manganese ore formation.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 4","pages":"913 - 932"},"PeriodicalIF":1.4,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782306","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":"Gold metallogenesis in craton-margin settings: Insights from orogenic to supergene processes in the Ilesha Schist Belt, SW Nigeria","authors":"Yusuf Ademola Abdu‑Raheem,&nbsp;Jing-Jing Zhu,&nbsp;Abiola Omotayo Oyebamiji,&nbsp;Li-Chuan Pan","doi":"10.1007/s11631-025-00846-y","DOIUrl":"10.1007/s11631-025-00846-y","url":null,"abstract":"<div><p>Gold deposits in craton-margin settings represent a distinctive metallogenic environment bridging intracratonic and mobile belt characteristics, yet remain less studied than cratonic and orogenic counterparts. This review examines gold metallogenesis in craton-margin environments using the Ilesha Schist Belt (ISB), a Nigerian Pan-African Belt, as a type example, integrating global analogues to build a framework for deposit genesis and fluid evolution. Four principal deposit types are identified: (1) orogenic lodes, (2) shear-hosted quartz veins, (3) lateritic–residual accumulations, and (4) alluvial–eluvial placers. Craton margins foster unique processes through structural reactivation, hybrid metamorphic–magmatic fluid systems, prolonged weathering that enhances supergene enrichment, and efficient mechanical concentration. A comparative analysis reveals systematic relationships between tectonic setting, deposit style, and fluid character. Key debates include the timing of mineralisation relative to metamorphism, fluid sources (metamorphic, magmatic, and mantle), the role of the cratonic lithosphere in metal endowment, and controls on supergene versus hypogene enrichment. We propose reclassifying the ISB as a hybrid orogenic–supergene system. Additionally, this terrain is recognised as a distinct metallogenic class, requiring specialised exploration approaches. A future research agenda emphases precise geochronology, integrated isotope studies, and quantitative weathering models, offering a refined exploration framework for craton-margin provinces.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 5","pages":"1151 - 1175"},"PeriodicalIF":1.4,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149098931","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":"Formation and magmatic evolution of the mangling plutonic complex in North Qinling, China","authors":"Rui-yang Liu,&nbsp;Shao-cong Lai","doi":"10.1007/s11631-025-00839-x","DOIUrl":"10.1007/s11631-025-00839-x","url":null,"abstract":"<div><p>The North Qinling orogenic belt experienced Mesozoic intracontinental tectonic–magmatic activity. The Mangling plutonic complex is composed of quartz diorite, granodiorite, k-feldspar granite, monzogranite, biotite granite, and granitic porphyry in the North Qinling orogenic belt, displaying high-potassium calc-alkaline features (SiO₂ = 64.78‒73.36 wt%, Mg# = 34.02‒40.65, A/CNK = 1.24‒1.67), enriched in LILE and LREE while depleted in HFSE. Isotopic data (I_Sr = 0.7064~0.7087, εNd(t) = − 7.05 to − 13.97, ²06Pb/²0⁴Pb = 17.61‒18.78, ²07Pb/²0⁴Pb = 15.47‒15.64) and zircon Hf isotopes (¹⁷⁶Lu/¹⁷⁷Hf = 0.000821‒0.001780, εHf(t) = − 6.16 ~ − 11.81) suggest crustal origin with mantle component input. The Mangling plutonic complex with a large time span (150‒128 Ma) has two magmatic intrusion periods: late Late Jurassic–early Early Cretaceous and middle Early Cretaceous. A mineral electron probe reveals the changes of conditions and the depth of emplacement during rock formation. Mineral thermometry reveals the cooling trend: 740 °C (zircon Ti), 710 °C (biotite Ti), 680 °C (titanite Zr), and 640 °C (quartz Ti), emplacement depth ~ 0.1 GPa (3.3 km). The isotope and major trace elements determine the mixing ratio of different magmas, indicating the Mangling plutonic complex mixing ratio: basic magma 6%‒28%; acid magma: 72%‒93%. This complex formed by plate subduction, collision, and post-collision extension. The transformation of this tectonic environment leads to the emplacement and superposition of different periods of magma, forming plutonic complex of granite → monzogranite → granodiorite → diorite.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"45 3","pages":"681 - 702"},"PeriodicalIF":1.3,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148196232","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}