Chemie Der Erde-Geochemistry最新文献

{"title":"Geochemical and geochronological characterization of the Tamanrasset W-Sn-(±Ta-Nb-Li) granites: Prolonged rare metal magmatism in the Laouni terrane (Central Hoggar, Algeria)","authors":"B. Zoheir ,&nbsp;A. Holzheid ,&nbsp;T. Graupner ,&nbsp;A. Zeh ,&nbsp;B. Lehmann ,&nbsp;S. Goldmann ,&nbsp;M. Steele-MacInnis ,&nbsp;K. Ali ,&nbsp;M. Kesraoui ,&nbsp;A. Bendaoud ,&nbsp;E. Fettous ,&nbsp;T. Lamri ,&nbsp;B. Ayad","doi":"10.1016/j.chemer.2025.126267","DOIUrl":"10.1016/j.chemer.2025.126267","url":null,"abstract":"<div><div>The origin of topaz-mica granites within the central Hoggar massif, along with their associated rare metal mineralization, remains a compelling subject despite extensive geochemical and geochronological research. This study presents new bulk-rock geochemical data and zircon U<img>Pb ages and Hf isotopic composition for the Tamanrasset W-Sn-(±Ta-Nb-Li) granites in the Laouni terrane, supplemented by Nd<img>Sm isotope analyses. These data enhance the understanding of the formation and tectonic setting of the investigated granites.</div><div>Petrographic and geochemical analyses identify four granite varieties: fine-grained monzogranite, fluorite-bearing two-mica granite, porphyritic topaz-alkali feldspar granite, and topaz-mica-albite granite. Generally, these rocks are low-P (P₂O₅ &lt; 0.14 wt%) and range from weakly metaluminous to strongly peraluminous (A/CNK = 0.94–1.83), with high degrees of fractional crystallization (50–90 %) evidenced by enrichment in F, Rb, W, Sn, Cs, Y, Zr, and Ta. The studied rocks feature distinct REE patterns, including strong negative Eu anomalies (Eu/Eu* ≤ 0.1) and M-type tetrad effects in topaz- and fluorite-bearing granites, while monzogranite shows weaker anomalies. Zircon saturation thermometry and <em>P</em>_<em>H2O</em> barometry suggest crystallization under low-temperature, water-rich conditions (11–15 MPa, &lt; 800 °C), with high fluorine activity and volatile-rich phases, suggesting shallow, evolved magmas. Zircon U<img>Pb dating defined ages of 605.4 ± 3.7 Ma for Aleméda monzogranite, 603.2 ± 2.6 Ma for topaz-alkali feldspar granite, and 592.9 ± 3.9 Ma for topaz-mica-albite granite, with younger ages (∼575–572 Ma) in two-mica granites from Tin Amzi-El Karoussa. Conversely, the Hanana-Hananère topaz-mica-albite granite has a distinctly older age of 638.0 ± 3.1 Ma.</div><div>The studied granites show diverse REE profiles, zircon εHf^(t) (−3.6 to −13.3), bulk-rock εNd^(t) (0.3 to −16.3), and model ages (1.3–2.4 Ga), indicating crustal reworking, mantle delamination, and partial melting. Orogenic collapse and mantle delamination triggered magmatic activity, leading to volatile-rich, evolved ferroan A2-type granites with rare-metal mineralization potential. Their isotopic variability suggests a transcrustal MASH system driven by mantle-crust interactions, with strong spatial association to mega shear zones, highlighting tectonic control on magma ascent and crustal reworking, and incorporation of ancient crustal materials.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 2","pages":"Article 126267"},"PeriodicalIF":2.6,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrology and P-T evolution of high-grade garnet metabasites from the Tin Begane area (Laouni terrane, South Algeria)","authors":"Amar Arab ,&nbsp;Amel Bitam-Derridj ,&nbsp;Khadidja Ouzegane ,&nbsp;Gaston Godard ,&nbsp;Sidali Doukkari","doi":"10.1016/j.chemer.2025.126260","DOIUrl":"10.1016/j.chemer.2025.126260","url":null,"abstract":"<div><div>The south of the Tin Begane region (Laouni terrane, Central Hoggar, southern Algeria) has been subjected to high grade metamorphism and shows well-preserved relicts of garnet-bearing metabasites boudinaged within metapelites and migmatites. These rocks have preserved a number of spectacular mineral assemblages and reaction microstructures. Two successive metamorphic stages have been recognised, on the basis of metamorphic microstructures and mineral compositions: (i) the main primary paragenesis consists of garnet porphyroblasts, amphibole, clinopyroxene, titanite and quartz; (ii) the retrograde stage is evidenced by clinopyroxene-amphibole-plagioclase symplectites, which developed mainly at the expense of garnet, as well as peculiar clinopyroxene-ilmenite symplectites after titanite. Garnet porphyroblasts are almandine-grossular (Alm_46–58 Prp_7–14 Grs_28–42 Sps_1–5) and show a smooth zoning pattern from the core to the outer rim. The clinopyroxene is diopside but shows slight chemical variations depending on its microstructural position in the rock (inclusion in garnet: <em>X</em>_<em>Fe</em> = 0.39; Al_total = 0.06 apfu; Ca = 0.90 apfu; ameboid crystals in the matrix: <em>X</em>_<em>Fe</em> = 0.42–0.47; Al_total = 0.15–0.16 apfu; Ca = 0.90–0.93 apfu; clinopyroxene in symplectite: <em>X</em>_<em>Fe</em> = 0.37–0.52; Al_total = 0.06–0.11 apfu; Ca = 0.91–0.95 apfu). The amphibole is (ferro-)tchermackite to (ferro/magnesio)-hornblende, with some grains exhibiting a smooth chemical zoning profile from core to rim. Plagioclase, either from the main paragenesis or from the Cpx + Pl symplectites, is anorthite (<em>X</em>_<em>An</em> = 0.92–0.97). To reconstruct the pressure-temperature evolution of a selected sample, two <em>P-T</em> pseudosections were calculated in the NCKFMASHTO system. The first pseudosection was modelled using the bulk-rock composition of the sample, whereas the second was calculated for the overall composition of the late symplectites, estimated by balancing the reaction that produced them. The results indicate that the studied metabasites have experienced a clockwise <em>P-T</em> path, with a decompression from peak conditions estimated at 13–15 kbar and 750 ± 50 °C down to 7–4.5 kbar and 810 ± 50 °C. The clockwise <em>P-T</em> path can be interpreted in terms of crustal thickening followed by exhumation, most likely during the Pan-African orogenesis.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 2","pages":"Article 126260"},"PeriodicalIF":2.6,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nb-Ta-Sn oxides as markers of magmatic fractionation and magmatic-hydrothermal evolution: The example of the Nuweibi granite intrusion, Eastern Desert, Egypt","authors":"Simon Goldmann ,&nbsp;Julie Anne-Sophie Michaud ,&nbsp;Torge Krummacker ,&nbsp;Chao Zhang ,&nbsp;François Holtz ,&nbsp;Ali A. Khudeir ,&nbsp;Sadeq Hamid ,&nbsp;Mohamed Abu El-Rus","doi":"10.1016/j.chemer.2024.126215","DOIUrl":"10.1016/j.chemer.2024.126215","url":null,"abstract":"<div><div>The Nuweibi rare-metal granite is located in the Central Eastern Desert of Egypt and represents a highly evolved leucogranite pluton that intruded into Neoproterozoic basement rocks of the Arabian-Nubian Shield. It is separated by the NNE-SSW trending oblique sinistral Dabr fault into two principal granite facies: a medium-grained albite granite in the western block and a porphyritic albite granite in the eastern block. The major ore minerals among the disseminated Nb-Ta-Sn mineralization are columbite-group minerals (CGM), wodginite, microlite, and cassiterite, which follow a distinct crystallization sequence including partial dissolution and late recrystallization. These ore minerals are usually strongly zoned, exhibiting a wide range of chemical compositions. As peculiarity, cm-sized euhedral columbite crystals with thin Ta-rich rims are found in the massive quartz cap of the eastern block of the intrusion. On the basis of mineral textures and microanalysis of mineral chemistry of the Nb-Ta-Sn oxides, we propose a genetic model for the evolution of the Nuweibi granitic intrusion involving magmatic, magmatic-hydrothermal, and subsolidus ore-forming processes: 1) upward migration of a granitic melt to the level of emplacement and fractional crystallization resulting in enrichment of the residual melt in incompatible elements (e.g., Ta, Nb, Sn) and volatiles (H₂O and F); 2) incipient magmatic crystallization of early Nb-rich CGM-1, albite, and snowball quartz and Ta enrichment in the melt (more incompatible than Nb); 3) onset of fluid exsolution (fluid saturation in the melt at the magmatic-hydrothermal transition), magmatic crystallization of CGM-2 with increasingly higher #Ta with co-existing fluid; 4) solidification of the quartz cap due to undercooling saturation with precipitation of columbite under hydrothermal conditions from magmatic fluids; 5) late magmatic fluid circulation, dissolution of the CGM and re-precipitation of CGM-3, followed by late-stage wodginite and microlite; 6) oblique sinistral and normal faulting after solidification of the Nuweibi granite, leading to the western block of the intrusion to move diagonally upwards resulting in today's opposing levels of exposure. As a result, the mineral paragenesis, texture, and mineral chemistry of Nb-Ta-Sn minerals prove to be remarkable tracers of the evolution from magmatic to hydrothermal conditions in rare-metal granites.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 2","pages":"Article 126215"},"PeriodicalIF":2.6,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface: “Geodynamic evolution and metallogeny of the Hoggar massif”","authors":"Torsten Graupner ,&nbsp;Abderrahmane Bendaoud ,&nbsp;Mohamed Hamoudi ,&nbsp;Astrid Holzheid ,&nbsp;Basem Zoheir ,&nbsp;El-Hocine Fettous ,&nbsp;Simon Goldmann","doi":"10.1016/j.chemer.2025.126291","DOIUrl":"10.1016/j.chemer.2025.126291","url":null,"abstract":"","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 2","pages":"Article 126291"},"PeriodicalIF":2.6,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenetic and dynamic links between felsic and mafic magmas: Insights from the Devonian post-collisional magmatism in the North Qaidam terrane, western China","authors":"Denghui Chen ,&nbsp;Hao Wu ,&nbsp;Dongdong Yan ,&nbsp;Chengxiang Li ,&nbsp;Huajun Wen ,&nbsp;Fuhao Xiong","doi":"10.1016/j.chemer.2025.126298","DOIUrl":"10.1016/j.chemer.2025.126298","url":null,"abstract":"<div><div>Felsic-mafic magmatism in post-collisional settings provides valuable insights into the growth and evolution of continental crust, but the interaction processes between felsic and mafic magmatism and their implications for the diversity of igneous rocks remain controversial. This study presents petrological, geochronological, geochemical, and Sr-Nd-Hf isotopic analyses of the Mohe felsic-mafic complex, a rare post-collisional composite pluton in the North Qaidam terrane (western China), to investigate the petrogenetic and dynamic links between felsic and mafic magmas. The results reveal that the Mohe complex, consisting of granite, granodiorite, diorite, and appinites, is genetically related and formed between ca. 408–400 Ma. The granites and granodiorites are classified as I-type and are characterized by enriched isotopic signatures, including whole-rock (⁸⁷Sr/⁸⁶Sr)ᵢ values of 0.714584–0.728765, εNd_{(400 Ma)} values of −7.75 to −5.56, and zircon εHf(t) values of −3.04 to −0.28. These rocks were primarily derived from partial melting of Mesoproterozoic to Paleoproterozoic crustal materials, with minor input from a mantle source. The appinites display depleted zircon Hf isotopic compositions (εHf(t) = +4.10 to +5.71), indicating derivation from an OIB-like depleted mantle source that was metasomatized by subducted slab-derived melts. The diorites show weakly enriched isotopes ((⁸⁷Sr/⁸⁶Sr)_<em>i</em> = 0.709358–0.713210, εNd_{(400 Ma)} = −2.99 to −2.73, εHf(t) = −1.35 to +3.54), and were formed by the mixing of 80–90 % appinitic magma with 10–20 % crustal-derived granitic magma. Our findings suggest that the Early Devonian magmatism in the North Qaidam terrane was likely driven by slab break-off-related geodynamic processes, where crust-mantle magma mixing, along with mineral accumulation and fractional crystallization, played a key role in the petrological diversity of the continental crust in a post-collisional extensional setting.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126298"},"PeriodicalIF":2.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143911631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced analysis of hydrothermal alteration and mineral prospecting through integration of ASTER and aeroradiometric data: A case study from the Ouarzazate region, Morocco","authors":"Ilham El Hakimi,&nbsp;Lahsen Achkouch,&nbsp;Younesse El Cheikh,&nbsp;Mohammad Taadid,&nbsp;Houda Bourouda,&nbsp;Ahmed Rachid,&nbsp;Ahmed Attou","doi":"10.1016/j.chemer.2025.126296","DOIUrl":"10.1016/j.chemer.2025.126296","url":null,"abstract":"<div><div>The study area, situated in the western segment of the Saghro Massif within the Anti-Atlas belt, is characterized by mineralized deposits, intricate lithological formations, and distinctive tectonic features. This research integrates ASTER imagery analysis with gamma-ray spectrometry data to map alteration zones and examine the geochemical and mineralogical processes that influence radioactive element distribution. Specific analytical techniques are applied to investigate relationships among argillic, phyllic, propylitic alterations, iron oxides, and regions with elevated concentrations of radiometric elements. Gamma-ray spectrometry data, including mono-elemental maps of radiometric components (potassium in %, equivalent uranium in ppm, and equivalent thorium in ppm), are analyzed alongside interpreted ASTER images to identify potential mineralization zones. Ratios of K/eU and K/eTh, along with the F parameter, are processed within a fuzzy model framework, which combines these datasets into a comprehensive mineral prospectivity map that serves as a tool for guiding exploration. This analysis identifies four hydrothermal alteration zones as highly promising for mineral exploration, suggesting a likely association between magmatic processes and spatially correlated hydrothermal alteration, thereby supporting further detailed exploration initiatives.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126296"},"PeriodicalIF":2.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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, zircon UPb ages and Hf isotopes of Tra Bong granitoid from Kontum massif, central Vietnam, and its petrogenetic significance","authors":"Nguyen Huu Trong ,&nbsp;Pham Trung Hieu ,&nbsp;Pham Minh ,&nbsp;Bui Kim Ngoc ,&nbsp;Nguyen Dinh Luyen ,&nbsp;To Xuan Ban","doi":"10.1016/j.chemer.2025.126295","DOIUrl":"10.1016/j.chemer.2025.126295","url":null,"abstract":"<div><div>Tra Bong granitoid, distributed in the northern area of Kontum, primarily consists of diorite and granodiorite. The main rock-forming minerals contain plagioclase (26–60 %), K-feldspar (8–22 %), quartz (15–33 %), biotite (3–7 %), and hornblende (9–20 %). The accessory minerals are sphene, apatite, zircon, and magnetite. Tra Bong granitoids are characterized by SiO₂ (58.83–65.8 %), total alkali (6.68–8.03 %), and A/CNK (0.80–0.90). They show high-K and relative enrichment of large-ion lithophile elements (Sc, Rb, and K), and the relative depletion of Nb, Ta, and Ti elements. The P₂O₅ content decreases with increasing SiO₂, and Th increases with Rb, a trend typical of I-type granites. All observed petrographic and geochemical characteristics suggested that the Tra Bong granitoid is typical of the I-type granite, formed in a subduction zone. The U<img>Pb crystallization age ranges from 254.5 to 255.0 Ma, coinciding with the Late Permian-Early Triassic magmatic activity, which was previously reported in the Truong Son belt. The ε_Hf(t) value together with the Hf zircon model ages (T_DM2) ranges from 1011 to 1159 Ma. The Tra Bong granitoid is a result of partial melting Mesoproterozoic mafic-intermediate magmatic rocks, with a minor amount of metasedimentary crust remelting. In conjunction with other Permian-Triassic magmatic rocks along Truong Son belt and the Song Ma suture, the Tra Bong granitoid represents magmatic activity related to subduction-collision of the Indochina and South China blocks and closure of Paleo-Tethys Ocean in the Late Permian-Early Triassic, along the Song Ma suture.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126295"},"PeriodicalIF":2.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying geochemical element distribution patterns through multiple-point geostatistical simulation and singularity analysis: A case study of the Wulonggou-Balong Area, Qinghai, China","authors":"Mengyu Zhao ,&nbsp;Qinglin Xia ,&nbsp;Wenjun Li","doi":"10.1016/j.chemer.2025.126294","DOIUrl":"10.1016/j.chemer.2025.126294","url":null,"abstract":"<div><div>The identification of geochemical element distribution patterns, the extraction of anomalies from geochemical exploration data, and the analysis of deep-level mineralization information are essential to guiding mineral prospectivity mapping. The spatial distribution of geochemical elements mainly arises from complex geological processes, making it challenging for standard deterministic interpolation techniques to capture its complex structure. In singularity analysis of element distribution, the size and geometric configuration of the sliding window significantly impact the geochemical anomaly distribution. Accordingly, this study incorporated the complex patterns extracted from multi-scale exploration geochemical data into a multiple-point geostatistical simulation framework to characterize geochemical element distributions at a fine scale. Fractal topography and singularity analysis were integrated as key analytical tools to identify and extract anisotropic geochemical anomalies. Stream sediment geochemical data from the Wulonggou–Balong area, Qinghai, China, were used as a case study to delineate gold-related geochemical spatial distribution patterns. The proposed multiple-point geostatistical (MPS) method enhanced anomaly intensity in local regions while achieving higher fidelity in reproducing spatial distribution patterns that align with regional geological trends. The spatial distribution patterns of geochemical anomalies, analyzed through diverse fractal topological relationships, highlight anisotropic characteristics in geochemical element distributions governed by ore-controlling factors. Practical application demonstrated that the methods effectively identify undetected weak anomalies associated with mineralization-favorable zones within gold geochemical distribution patterns and minimize uncertainty in anomaly interpretation.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126294"},"PeriodicalIF":2.6,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronology and petrogenesis of magmatic and high-grade metamorphic rocks in the Eocene Chapedony core complex: New insights into the basement geology of Iran","authors":"Zeynab Gharamohammadi ,&nbsp;Peter A. Cawood ,&nbsp;Ali Kananian ,&nbsp;Reza Nozaem ,&nbsp;Yona Jacobsen ,&nbsp;David Lentz ,&nbsp;Jafar Omrani","doi":"10.1016/j.chemer.2025.126290","DOIUrl":"10.1016/j.chemer.2025.126290","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Arabia-Eurasia convergence zone provides an evolving record from oblique subduction to continental collision resulting in multiple transient tectonothermal events. Although the subduction of the Neotethys below the Iranian terranes and its relation to the arc and back-arc magmatism throughout the late Mesozoic and Cenozoic in Iran has been documented, the detailed geochemical and isotopic transition from subduction to back-arc extension was not constrained. This study reports the first evidence into the petrogenesis of magmatic diversity of Chapedony core complex (CCC) and the coexistence of Nb-enriched rocks and adakite-like rocks as a result of old crustal recycling. Integrated study of petrography, whole-rock major- and trace-element geochemical data supported with Sr and Nd isotope compositions, zircon U&lt;img&gt;Pb and traces, and zircon Hf isotope analyses reveal a protracted and pulsed evolution of the CCC. The complex consists of leucosome-bearing gabbro-diorite-granodiorite, quartz diorite, and biotite granite that formed between 50 and 40 Ma, but contains amphibolite (metabasite) bodies with zircon cores yielding U&lt;img&gt;Pb ages of 518 Ma and 189 Ma with MORB- and OIB-like characteristics, respectively. Biotite granites are divisible into two types; Type 1 have zircons with a wide range ages, while Type 2 are biotite granites with Eocene ages and lack inherited zircons. Biotite granites Type 1 yield a range of zircon ages (45–3200 Ma) with the youngest magmatic ages late Neoproterozoic-Early Cambrian, Triassic (240 Ma), and Eocene (48 Ma). εHf (t) values for zircon grains range from −23.95 to 13.13 for biotite granites (Type 1), −4.76 to 6.78 for amphibolites, and − 6.25 to 6.96 for Eocene mafic-felsic rock units. Biotite granites (Type 1) have I&lt;sub&gt;Sr&lt;/sub&gt; and εNd values ranging from 0.7177 to 0.7308 and − 14.8 to −7.4, respectively, whereas these values for the amphibolites are 0.7056 to 0.7090 and − 4.4 to 11.3, respectively. The mid-Eocene rock units of the CCC have I&lt;sub&gt;Sr&lt;/sub&gt; of 0.7050 to 0.7136 and εNd values of −3.9 to 8.9 gabbro-diorite-granodiorite, 3.3 to 16.3 for quartz diorite, and − 5.3 to −0.9 biotite granite (Type 2). The recorded zircon Hf isotopes along with I&lt;sub&gt;Sr&lt;/sub&gt; and εNd values indicate that a hybrid and old mantle (MORB+OIB) previously metasomatised by subduction of old enriched components (biotite granite Type 1) into the mantle, predating Eocene appinite-like mafic magma generation. Subsequent partial melts of such a source generate Eocene appinite magmas, as transitional rocks, which evolved to Eocene intermediate-felsic rocks through magma-crust interaction and accumulation/fractionation after the initial melts formed in the lower crust. The timing of the CCC formation (50–40 Ma) corresponds to an amphibolite metamorphism involving temperatures of 600–800 °C, associated with partial melting during the regional back-arc extension. The formation of new crust, through the reactivation and recycl","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126290"},"PeriodicalIF":2.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectroscopic signatures for expeditious monitoring of contamination risks at abandoned coal mine sites","authors":"Jelena Milinovic ,&nbsp;Patrícia Santos ,&nbsp;Jorge Espinha Marques ,&nbsp;Deolinda Flores ,&nbsp;Aurora Futuro ,&nbsp;Carlos M. Pereira ,&nbsp;Manuel Azenha","doi":"10.1016/j.chemer.2025.126292","DOIUrl":"10.1016/j.chemer.2025.126292","url":null,"abstract":"<div><div>Soil acts as a natural ‘filter’, playing a crucial role in the transfer of geogenic and anthropogenic pollutants from abandoned coal mine sites to surrounding water bodies. Key indicators of soil contamination, such as pH, electrical conductivity (EC), and organic matter (OM), expressed as loss-on-ignition (LOI), can signal contamination risks when they deviate from optimal ranges. To enable sustainable risk assessment through monitoring of pH, EC, and LOI, streamlined spectroscopic techniques Fourier transform infrared (FTIR), near-infrared (NIR), Raman, and X-ray fluorescence (XRF) were applied in combination with multivariate analysis (MVA), to soil samples from two abandoned coal mines in NW Portugal. Partial least squares (PLS) regression models demonstrated that XRF spectroscopic data provided the most accurate assessment of soil pH, EC, and LOI at the local scale (R² = 0.92–0.99). The most significant spectroscopic signatures, identified through weighted regression coefficients (B_w), enabled robust predictions of these key soil parameters. These findings highlight that these geochemical variables outperform molecular spectroscopy techniques for efficient and environmentally relevant risk monitoring of contamination in abandoned coal mine sites.</div></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"85 3","pages":"Article 126292"},"PeriodicalIF":2.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}