Environmental and Earth Sciences

Abstract: Cobalt-rich ferromanganese (Fe–Mn) crusts from the Magellan Seamount Trail (MST), western Pacific Ocean, record long-lived hydrogenetic mineralization interrupted by dissolution, sedimentation, phosphatization, and renewed crust growth. However, age assignments for phosphatized early crust layers remain uncertain because calcareous nannofossils commonly occur in carbonate fluorapatite (CFA) veinlets, pores, cavities, and fractures rather than in the primary Fe–Mn oxyhydroxide matrix. Here, we combine calcareous nannofossil biostratigraphy with in situ U–Pb LA-ICP-MS dating of CFA to constrain the multistage history of a four-layer Co-rich Fe–Mn crust from the eastern slope of Govorov Guyot. The section comprises, from bottom to top, Layer I-1, sublayer I-2b, Layers II, and III. Calcareous nannofossil assemblages indicate Late Paleocene–Early Eocene fossil-bearing phosphatized carbonate material in Layer I-1, a Late Oligocene–Early Miocene assemblage in sublayer I-2b, Middle Miocene carbonate material in the lower part of Layer II, a Late Miocene–Early Pliocene assemblage in the II–III transition, and Pliocene–Pleistocene assemblages in Layer III. This age sequence in the young part of the crust is consistent with the established MST chronostratigraphic and biostratigraphic scheme. U–Pb dating of CFA reveals additional Late Cretaceous and Miocene phosphatization events. CFA from the phosphatized carbonate substrate beneath Layer I-1 yielded an age of 85.8 ± 4.7 Ma, consistent with the previously documented Turonian–Coniacian phosphatization event involving the oldest known Pacific CFA at Govorov Guyot. CFA veinlets within Layer I-1 yielded ages of 75.3 ± 2.6 Ma and 73.1 ± 4.9 Ma, documenting Late Cretaceous phosphatization of the old Fe-Mn crust section. CFA from the phosphatized sublayer I-2b yielded an age of 15.8 ± 2.3 Ma, recording an additional Early–Middle Miocene phosphatization event. The dated CFA veinlets demonstrate that the Fe–Mn matrix of Layer I-1 predates the 75–73 Ma phosphatization event and is therefore approximately 20 Myr older than the maximum age inferred from calcareous nannofossil biostratigraphy. The chronostratigraphic scheme and generalized section of MST Co-rich Fe–Mn crusts should therefore be complemented by a texturally controlled U–Pb chronology of phosphatization events, particularly for the Late Cretaceous crust succession.

Abstract: Recent years, a series of pegmatite-type rare-metal deposits and occurrences—including Chakabeishan, Shaliuquan, Jinshuikou, Adatan, and Gaduo—have been reported in Qinghai, sparking a wave of rare-metal exploration activity. The Southern Kunlun Convergence Zone is a key tectonic unit of the Eastern Kunlun Orogenic Belt; however, systematic geochronological and geochemical constraints on the granitic-pegmatitic rare-metal mineralization system within this region have long been lacking. This study focuses on the newly discovered beryllium ore body at Wulugou in the Southern Kunlun Mountains. Samples from the ρ10 and ρ38 beryllium-bearing pegmatite veins were selected for petrological analysis, LA-ICP-MS zircon-monazite U-Pb geochronology, and whole-rock major and trace element analyses. Zircon Lu-Hf and monazite Sm-Nd isotope analyses were also conducted on the ρ10 and ρ38 beryllium-bearing pegmatite veins. This study precisely determined the diagenetic and mineralization ages of the pegmatites, systematically clarified the genesis and evolutionary relationships among the ore-bearing pegmatite, the surrounding granite, and the barren pegmatite, and elucidated the characteristics of the magma source region and the mechanisms of beryllium mineralization. LA-ICP-MS dating results for monazite and zircon in the pegmatites indicate that the ore-bearing pegmatite formed during the Early Devonian (404.9–408.3 Ma). Whole-rock geochemical analysis indicates that the albitized granites, barren pegmatite, and beryllium-bearing pegmatites in the study area constitute a continuous, homologous, highly differentiated evolutionary sequence, all of which are highly differentiated granites. As the degree of crystallization increases, the rock undergoes continuous enrichment in SiO₂, Na₂O, MnO, P₂O₅, and Be, while K₂O, Ca, and Sr are progressively depleted. The effects of the four rare-earth groups, along with the Zr/Hf and K/Rb ratios, collectively indicate that saturation and dissolution of volatile fluids in the late stage are the key controlling factors in the precipitation of beryllium ore. Primary magmatic zircon εHf (t) = −2.69 to +1.95 (mean + 0.76); two-stage Hf model age: 1.28 to 1.57 Ga; Isolated εNd (t) = -6.71 to -5.44, Nd two-stage model age 1.57 to 1.68 Ga, The source-area discrimination diagrams all fall within the muddy clastic-melt zone, indicating that the parent magma originated from low-degree partial melting of the Middle Proterozoic Wanbaogou Group metamorphic basement, accompanied by contamination by mantle-derived magma. This study discovered Early Devonian Caledonian-period pegmatite-type beryllium deposits in the Southern Kunlun Mountains, providing a theoretical basis and practical reference for the exploration of granite-pegmatite-type beryllium deposits in the Southern Kunlun Mountains.

Abstract: Sedimentary-basin brines are increasingly evaluated as unconventional lithium (Li) resources, but legacy water-chemistry datasets commonly lack Li measurements. This study develops a geological and geochemical workflow for screening Li prospectivity in the Northern Gondwana Region (NGR). Major-ion, potassium (K), boron (B), bromine (Br) and stable-isotope data from Triassic, Jurassic and Paleogene carbonate aquifers were integrated with basin history and compared with published Li-bearing brines. Na-Cl facies, Cl-Br systematics and isotope compositions indicate residual evaporative components and varying degrees of water-rock interaction, whereas the Paleogene aquifer shows greater meteoric dilution. Triassic and Jurassic samples occupy the region of B-K space populated by published Smackover brines with higher Li concentrations. Comparable associations among Li, K, B and Br occur in Devonian Alberta brines, although Qianjiang data demonstrate that these relationships are basin dependent. The convergence of potential Li sources, evaporative evolution, burial-related water-rock interaction, organic-matter maturation and possible hydrothermal circulation identifies the Triassic and Jurassic aquifers as higher priorities for direct Li analysis. The workflow is an exploration-screening method; it neither predicts Li concentration nor establishes a mineral resource.

Abstract: To investigate how the anatexis of accretionary complexes contributes to crustal differen-tiation in orogenic belts, we present an integrated analysis of whole-rock geochemistry, zircon U-Pb geochronology, and zircon Lu-Hf isotopes for Late Carboniferous granitoids from the Dunhuang orogenic belt. Zircon U-Pb dating indicates that the granitoids were emplaced between 323 and 312 Ma. Their zircon εHf(t) values (−39.3 to 10.7) are largely negative, suggesting derivation primarily from ancient crustal materials. Geochemical correlations and field relationships between the granitoids and their wall rocks suggest that the magmatic sources were dominated by meta-sedimentary rocks with minor me-ta-mafic rocks. The systematic whole-rock Rb-Sr-Ba variations are attributed to wa-ter-fluxed melting of muscovite in a metasedimentary source. Given the continued activity of the Dunhuang subduction zone during the Late Carboniferous, we infer that elevated temperature combined with fluid-rich conditions in the deeper accretionary wedge trig-gered anatexis of the accreted materials. The segregation and upward migration of granit-ic magmas leave a residue within the deeper accretionary wedge that resembles the lower continental crust in composition. This process enhances vertical differentiation within the orogenic belt crust and likely plays an important role in transforming loose accreted ma-terials into more mature continental crust.

Abstract: Permian sedimentary manganese carbonate deposits in the Qiling Basin exhibit substantial resource potential, yet their depositional environments and precipitation pathways remain insufficiently constrained. This study integrates petrographic, mineralogical, whole-rock geochemical, and carbonate C–O isotope data from the Shuibutou Mn deposit in southern Hunan. We compare this deposit with the coeval Dongxiangqiao deposit and other Permian marine sedimentary Mn deposits to constrain its depositional setting, Mn-carbonate precipitation mechanisms, and potential Mn sources. The Shuibutou ores contain 10.88–17.18 wt.% MnO and are characterized by spherulitic–oolitic textures, abundant bioclasts, and framboidal pyrite. Mo–U enrichment indicates anoxic bottom waters, whereas the near-marine δ¹³C_carb values of ore carbonates (−0.24‰ to 1.28‰) are consistent with pre-cipitation within a marine carbonate system and suggest direct precipitation of Mn(II) carbonates from dissolved Mn²⁺ under anoxic conditions. In this setting, dissolved Mn²⁺ accumulated below the chemocline. Partial dissolution of platform-derived calcite grains near the chemocline increased local dissolved inorganic carbon and alkalinity, driving Mn-carbonate supersaturation and the authigenic precipitation of manganoan calcite, ultimately forming manganese carbonate ores. The low Al/(Al + Fe + Mn) ratios, high Fe/Ti ratios, and Co–Ni–Zn and REY geochemical characteristics are consistent with a possible contribution from Mn-rich deep fluids to the dissolved Mn²⁺ inventory of the basin waters. Similarities in mineralogy, geochemistry, and depositional setting between Shuibutou and Dongxiangqiao point to a possible regional role for the direct precipitation of Mn(II) carbonates under anoxic conditions in the Middle Permian Qiling Basin. Relatively deep intraplatform basins may therefore represent favorable targets for manganese carbonate exploration and provide a reference for exploration targeting of Permian sedimentary Mn deposits within the Qiling Basin.

Abstract: The peninsular India is an area of ~16,00,000 sq. km, bound by mountain or hill ranges. It comprises dominantly the Archean-Proterozoic terrain (APT) in the south, Deccan trap Volcanic Terrain (DVT) in the middle and, Mixed-Lithology Terrain (MLT) in the north. Almost all rivers of peninsular India originate in mountain ranges or high plateaus, rain-fed, drain continental rocks and flow westwards into the Arabian Sea or eastwards into the Bay of Bengal (Figure 1). River sediments are formed from weathering and erosion of continental rocks in their drainage basins. Since the drainage basins of the rivers cover the entire landmass of peninsular India, the average geochemical compositions of sediments in the rivers may reflect the average composition of the continental crust. Here, we highlight the differences in the average chemical composition of sediments in rivers along the east and west coast of India that drain dominantly similar geological terrains, update the geochemical composition of the Peninsular India Rivers Average Clay (PIRAC) based on the sediments from 104 rivers and, suggest that the composition of PIRAC serves as reference sediment for the Indian sub-continent. We found that the major elements in river sediments are variably affected by the intensity of weathering, with depleted mobile elements and enriched immobile elements. On an average, the clays from the east coast rivers are enriched with Si, Ti, Fe, Mg and Mn, and Na and depleted with Ca and P relative to those of the west coast rivers. PIRAC showed more depleted Si, Mg, Ca, Na and K and enriched Ti, Fe, Mn and P relative to the Post Archean average Australian Shale (PAAS). Weathering indices suggest that the sediments are extremely weathered in the southern peninsular India and, strong to moderately weathered in the central and northern peninsular India. The average total trace element content (∑TE) of the clays was much higher for the east coast rivers than that of west coast. The ∑TE of PIRAC was lower than in PAAS. The PAAS-normalised trace elements of PIRAC showed high transition trace elements (∑TTE) and low high-field strength elements (∑HFSE) and large-ion lithophile elements (∑LILE). The average rare earth element content (∑REE) of the clays increased from APT to MLT for the east coast rivers but decreased in the west coast rivers. The ∑REE of PIRAC was higher than in upper continental crust (UCC) but lower than in PAAS. The PAAS-normalised REE of PIRAC showed MREE- and HREE- enriched and LREE- depleted pattern, with positive Ce and Eu anomalies. PIRAC is significantly enriched with mafic component dominated material despite Archean-Proterozoic rocks are abundantly wide spread in the peninsular India. The intensity of chemical weathering and, erosion and transportation of easily eroded mafic rocks relative to that of felsic rocks resulted in deposition of mafic component-dominated material at the lower reaches of almost all rivers. Since the composition of PIRAC is significantly different from that of UCC/PAAS and other reference sediments, PIRAC serves as the most suitable reference sediment for the Indian subcontinent.

Abstract: To determine the reprocessing potential of mining liabilities, a comprehensive evaluation of the tailings deposit at the former Halcon mining unit in central Peru was conducted. Direct and indirect methods were employed, including geophysical surveys, sampling through six drill holes up to 9.62 meters deep, textural analysis, mineralogical characterization (optical microscopy, SEM, XRD, and reflectance spectroscopy), and ICP-MS chemical analysis, complemented by geostatistical modeling for resource estimation. Geochemical and mineralogical results reveal highly oxidizing, acidic conditions (pH 1.83–4.91) and significant concentrations of Zn (5.46%), Pb (1.58%), Cu (1.67%), Ag (244 ppm), and Au (3.6 ppm). These economic minerals predominate in fine-grained fractions with high degrees of liberation, favoring metallurgical recovery. Geostatistical modeling estimated a total tailings tonnage of 87,642 tons, highlighting zones of high localized economic potential, particularly for Zn and Ag. Considering specific recovery scenarios, penalties, operational costs, and metal prices, a net financial benefit of approximately US$11.35 million was projected. This pioneering study demonstrates the feasibility of converting environmental liabilities into economic assets through strategic reprocessing initiatives, contributing a robust model for mine tailings valorization within the South American circular economy framework.

Abstract: Located 30 km south–southeast of Kabul in Logar province, Aynak is the largest and best-known copper orebody in Afghanistan. The deposit is hosted by the Loy Khwar Formation, a Neoproterozoic-Cambrian metasedimentary sequence of dolomite marble, carbonaceous quartz schist and quartz–biotite–dolomite schist. The primary ore minerals are chalcopyrite and bornite with less abundant pyrite and minor cobaltite, chalcocite, pyrrhotite, sphalerite and molybdenite. Sulphides occur as bedded laminae and disseminations, in metamorphic segregations, and in syn- to post-metamorphic cross–cutting veins. The geochemistry of sulphide-rich separates from Central and Western Aynak (n=31), analysed by ICP-MS, confirm and quantify previous petrographic observations indicating varying admixtures of sulphide species. Co and As enrichment in chalcopyrite-dominant samples is consistent with cobaltite whereas Co enrichment in the absence of arsenic suggests the presence of carrollite. Fluid inclusion analyses of secondary quartz-hosted inclusions indicate interaction with moderately hot (approximately150- 300⁰C; pressure-uncorrected), highly saline (32.1 to 47.4 equivalent wt% NaCl) chloride-rich brines. It is uncertain whether these fluid parameters relate to primary copper transport and deposition, or to remobilisation during metamorphism. Nevertheless, comparison with analogous sediment-hosted copper deposits suggests that highly saline basinal brines played an important role in the formation and evolution of the deposit. Occurrences of scapolite provide additional evidence for a model of brine-related mineralization. Together with previously published mineralogical, lithogeochemical and sulphur isotope evidence, these findings support a sedimentary–diagenetic origin for the Aynak copper deposit that is broadly comparable with sediment-hosted stratiform copper systems of the Central African Copperbelt.

Abstract: Hydrocarbon reservoirs remain a cornerstone of the global energy landscape; precise reservoir characterization is essential to evaluate the viability of crude oil production. Addressing the challenges inherent in low-permeability, low-porosity formations and near-wellbore environments is critical for maintaining sustainable production. Due to the heterogeneity of deep reservoir cores, non-destructive analytical methods are required for sample reuse. Nuclear Magnetic Resonance (NMR) techniques - specifically low-field (LF) NMR and Magnetic Resonance Imaging (MRI) - have emerged as essential tools for the spatial characterization of pore networks. While these methods are well-established for determining porosity and permeability in sandstones, the characterization of carbonates is more complex due to their intricate chemistry, multi-scale geological features, and geo-mechanical properties. This review article synthesizes the theoretical framework and practical applications of NMR for determining the petrophysical properties of sandstone and carbonate rocks, including porosity, permeability, and fluid saturations. We provide a concise historical overview and a technical evaluation of the primary equations used in LF-NMR data inversion. We examine recent advancements in LF-NMR and MRI applications, identify persistent challenges and future perspectives, and summarize key lessons learned from the recent literature. Hence, this review provides a comprehensive roadmap for applying magnetic resonance to rock core analysis.

Abstract: The fifth member of the Upper Triassic Xujiahe Formation (T₃x⁵) in the southwestern Sichuan Basin contains widely developed organic-rich source rocks, which represent a crucial interval for hydrocarbon exploration in the region. This study systematically evaluates the organic geochemical characteristics, spatial distribution, and hydrocarbon generation potential of these source rocks using total organic carbon (TOC) analysis, organic matter typing, vitrinite reflectance (Ro) measurements, and basin modeling. The results show that the upper and lower submembers have average TOC values of 3.19% and 3.41%, respectively, with organic matter predominantly of mixed sapropelic-humic type (Type II₂). TOC content generally increases from uplift areas to depressions, reflecting the control of depositional environment on organic matter preservation. Thermal maturity exhibits a westward increase and eastward decrease, with the southwestern part reaching high to over-mature stages (Ro generally >1.3%), while the eastern part remains in the condensate-wet gas window. Thickness of the upper submember ranges from 60 to 320 m, with depocenter in the central-southern part of western Sichuan; the lower submember is 60-200 m thick, centered in the Chengdu-Deyang area. Basin modeling, which integrates burial and thermal histories, estimates a cumulative gas generation of approximately 192×10¹² m³ (192 trillion cubic meters), with the highest generation intensity coinciding with the western Sichuan depression. It is concluded that the T₃x⁵ source rocks possess excellent material bases and huge resource potential. Tight sandstone reservoirs adjacent to the gas kitchen should be prioritized in future exploration, with differentiated strategies adapted to various maturity zones.

Abstract: The Siberian Traps has been a reference object for geologists for many years in understanding the origin of Large Igneous Provinces on Earth. Data from high-magnesium rocks in its northern region have traditionally been used to create genetic models. However, the central and southern parts, consisting of the basaltic rocks, remain significantly unexplored, despite their important role in volcanic evolution within the province. This article presents new structural, mineralogical, and geochemical data from the tuff-lava sequence in the central region of the Tunguska syneclise. The studied sections are located along the Lower Tunguska River Valley, near Tura, Babkino, and Vanavara, in the Podkamennaya Tunguska Valley. They consist of pyroclastic rocks belonging to the Korvunchansky Formation, which are overlain by basalts and tuffs of the Nidymsky and Kochechumsky Formations (Early Triassic, 251 Ma). Major and trace element analysis of 64 samples shows that basalts from all formations are relatively similar in composition, belonging to the tholeiite type with MgO concentrations ranging from 4.2% to 7.8%. Trace element patterns exhibit negative Ta-Nb anomalies and positive Pb anomalies, which are typical of the Siberian Platform basalts. Tuffs, on the other hand, differ from the basalts by having higher SiO₂ and K₂O contents and steeper rare earth element (REE) patterns. Isotopic analysis (Sr-Nd) confirms this difference and suggests that basalts and tuffs originated from two distinct magma sources. The Nidymsky basalts have positive εNd values (+2.21 to +3.10), similar to those of the Morongovsky and Mokulaevsky basalts in the Norilsk area. Tuffs, on the other hand, exhibit negative εNd (-1.33 to -4.5) and elevated 87Sr/86Sr (>0.706), in comparison with basalts (0.704-0.706). Geological observations reveal that pyroclastic rocks play a significant role in the initial stages of volcanic activity. The main result of this study is that tuffs from the Korvunchansky and Khakanchansky Formations (in the south and north of the region, respectively) are identical in their geochemical characteristics. This similarity suggests the existence of a single pyroclastic cover over the Siberian Platform. These tholeiitic pyroclastic rocks, which are similar in composition to the lower crust, mark the beginning of trap magmatism, rather than picrites, as suggested by the plume model.

Abstract: Petrology, as one of the fundamental branches of geology, has consistently sought to answer fundamental questions regarding the origin, evolution, and diversity of igneous and metamorphic rocks. This review article, adopting a comprehensive approach without relying on new field data, examines the conceptual and methodological evolution of petrology from its formative years to contemporary research horizons. In the first section, the theoretical framework governing igneous petrology—including concepts of fractional crystallization, partial melting, magmatic series, and the tectonic setting of magmatism—is critically evaluated. In the second section, the principles of phase equilibria, metamorphic facies, pressure-temperature-time paths, and the role of fluids in rock metamorphism are elaborated. Furthermore, the application of geochemical methods, including stable and radiogenic isotopes, alongside novel approaches such as machine learning applications and thermodynamic modeling, are introduced as contemporary research perspectives. The article concludes by emphasizing that the ultimate goal of petrology is the integration of micro-scale observations with macro-scale tectonic theories to construct a unified picture of Earth's evolutionary history.

Abstract: This article describes the mineralogical and geochemical features of the Marsyaty sedimentary deposit of Fe and Mn ores in the Northern Urals (Russia). Oolitic ironstones are localized in coastal sandstones of the Cenomanian age. Сarbonate Mn ores lies within siliciclastic sediments of the Lower Paleocene and are separated from the oolitic ironstone by a layer of gravel. Authigenic iron oxyhydroxides, chamosite/bertierite and superimposed siderite predominate in the ironstones; kaolinite, apatite, perhamite, calcite and dolomite are minor and rare. Rhodochrosite and rencieite are major minerals of the Mn ore; layer Mn-silicates (caryopilite, parsettensite?) are minor and rare. Both ore types contain authigenic glauconite, montmorillonite, sulfides (sphalerite/wurtzite, galena, pyrite), gibbsite/boemite, REE phosphates. The detrital component of both types of ores is represented by clasts of quartz, ilmenite, zircon, monazite, epidote, titanite, muscovite, and feldspars. The δ13Сcarb varies from -18.5 to -23.3 in carbonate ironstone and -10.0 to -41.0 ‰ PDB in manganese ore. The light isotopic composition of carbon and numerous organic relics indicate the participation of microbes in both types carbonate ore formation process. It is concluded that iron and manganese ores belong to a joint transgressive series of sedimentary rocks that arose sequentially during the evolution of the West-Siberian basin. The unique feature of the Marsyaty deposit is that, within a limited area and over a short geological period, favorable conditions were realized first for the accumulation of iron and manganese, and then only for manganese.

Abstract: Accurate prediction of gold enrichment is critical for mineral exploration and resource evaluation, particularly in data-limited environments where only geochemical information is available. This study evaluates machine learning (ML) models against linear baselines for predicting relative gold enrichment defined as ln(Au/G10), where G10 represents the geometric mean of ten predictor elements (S, Fe, Al, Si, Mn, Sr, Ni, Cu, K, Ti). A total of 53,126 samples from a sulphide-hosted orogenic gold system were subjected to compositional data analysis (CoDA) preprocessing, including multiplicative replacement of below-detection values, closure to a constant sum, centred log-ratio (CLR) transformation of predictor variables, and robust outlier filtering using the Minimum Covariance Determinant (MCD) method. After screening, 41,626 samples were retained for modelling. Comparative modelling included linear baselines—Ordinary Least Squares (OLS), Ridge, Lasso, and Huber—and non-linear ML algorithms: Random Forest (RF), Support Vector Regression (SVR), k-Nearest Neighbours (kNN), and Multi-Layer Perceptron (MLP). Under the non-circular formulation, nonlinear models consistently outperformed linear baselines. Random Forest achieved the strongest validation performance (R2 ≈ 0.51), followed closely by MLP and SVR, while linear models remained substantially weaker (R2 ≈ 0.31). SHapley Additive exPlanations (SHAP) applied to the Random Forest model identified sulphur (S) and iron (Fe) as the most influential predictors, consistent with sulphide-controlled gold mineralization processes in orogenic systems. The model predicts relative gold enrichment based solely on multielement geochemistry, providing a robust and interpretable proxy for mineralization intensity in data-constrained environments. This study demonstrates that machine learning models, when combined with CoDA-correct preprocessing and a non-circular target formulation, can provide geologically meaningful and methodologically robust predictions of gold enrichment. The workflow offers a transparent and reproducible framework for early-stage exploration targeting using multielement geochemistry.

Abstract: This study investigates the provenance, weathering history, and tectono-sedimentary evolution of Lower Ediacaran siliciclastic rocks of the Imiter Formation (Saghro Group, Imiter Sub-inlier, Anti-Atlas, Morocco) deposited along the northern margin of Gondwana. An integrated approach combining petrography, whole-rock major and trace element geochemistry, rare earth elements (REE), Sm–Nd isotopes, and organic geochemistry (TOC and δ¹³Cₒᵣg) was used to constrain sediment sources and deposi-tional conditions. Geochemical proxies, including Th/Sc, La/Sc, and Zr/Sc ratios, to-gether with REE distribution patterns, indicate that the sediments were mainly derived from felsic to intermediate rocks of the upper continental crust, with only minor sedi-ment recycling. The negative εNd(t) values (−8.5 to −6.2) and Paleoproterozoic Nd model ages (1.6–2.1 Ga) further suggest erosion of evolved crustal sources related to the West African Craton. Weathering indices (CIA, CIW, PIA) suggest weak to moder-ate chemical weathering under predominantly arid conditions. Redox-sensitive proxies (V–Ni, V/Cr, V/(V+Ni)) and low TOC contents (0.1–0.3 wt.%) indicate deposition under mainly oxic to dysoxic conditions with only transient reducing episodes. Tectonic dis-crimination diagrams, supported by regional magmatism, point to sedimentation within an extensional basin evolving from active margin to continental rift conditions during the late Pan-African orogeny. The Imiter Formation records a system dominat-ed by crustal recycling, syn-rift tectonics, and dynamic redox conditions in a shallow marine environment.

Abstract: To reveal the solute sources, migration and enrichment mechanisms of water bodies in the endorheic lake region of the Qiangtang Plateau, Tibetan Plateau, and to clarify the hydrogeochemical cycling patterns in alpine arid zones, this study took typical en-dorheic lake areas in the region as the research object, conducted a systematic hydro-geological survey, collected 28 groups of water samples of various types (including springs, rivers, thermal springs, freshwater lakes, salt lake brines, atmospheric precip-itation and glacial meltwater), tested their major ions, trace elements and physical properties, and comprehensively investigated the hydrogeochemical characteristics, evolution laws and solute sources of water bodies, quantified the dominant control-ling factors and established a conceptual hydrogeochemical model by combining methods such as PHREEQC modeling, principal component analysis (PCA) and Pear-son correlation analysis; the results show that water bodies in the study area exhibit a distinct evolutionary gradient, from the low-salinity HCO₃-Ca recharge end-member, through transitional HCO₃·SO₄-Ca(Mg) water, to highly mineralized Cl-Na(SO₄·Cl-Na) salt lake brine, with synchronous enrichment of Li, B, As and other elements; solute sources are controlled by a ternary coupling mechanism of evaporative concentration, rock weathering and leaching, and deep geothermal fluid input, while cation ex-change and mineral dissolution-precipitation further regulate ionic ratios; As, Li, B and Cl⁻ display conservative migration in non-hydrothermal waters, whereas thermal springs show unique geochemical signatures due to the input of deep-seated fluids; PCA reveals that evaporative concentration (contribution rate 55.39%) is the dominant controlling factor, rock weathering (17.09%) provides the basic solute load, and the coupled process of deep fluid mixing and carbonate precipitation (14.21%) regulates elemental fractionation, and this study constructs a conceptual model of "multi-source recharge–water–rock interaction–evaporative concentration", which clarifies the evo-lutionary laws of regional water bodies and provides a scientific basis for water cycle research and green exploration of strategic mineral resources in salt lakes of the en-dorheic regions on the plateau.

Abstract: Geochemical anomaly detection plays a critical role in mineral exploration, yet conven-tional methods are often limited by compositional effects, sensitivity to outliers, and in-sufficient consideration of spatial relationships. To address these issues, this study pro-poses an integrated analytical framework that combines compositional data analysis and spatial statistics for robust geochemical anomaly identification. The framework incor-porates isometric log-ratio (ILR) transformation to eliminate the closure effect, robust principal component analysis (RPCA) to extract stable geochemical patterns, local indi-cators of spatial association (LISA) to characterize spatial clustering, and compositional balance analysis (CoBA) to enhance anomaly signals. The method is applied to the Barkol Lake area in the Eastern Tianshan, a key metallogenic belt within the Central Asian Orogenic Belt. The results reveal significant geochemical anomalies characterized by Cu-associated element assemblages (e.g., Cu–Ni–Cr), which are spatially correlated with major fault zones and volcanic–intrusive complexes. The identified anomalies show strong consistency with known mineral occurrences and delineate several prospective targets for copper polymetallic mineralization. Compared with conventional approaches, the proposed framework demonstrates improved robustness to outliers, enhanced sensi-tivity to weak anomalies, and better integration of compositional and spatial constraints. These advantages highlight its effectiveness for geochemical anomaly detection and mineral prospectivity mapping in complex geological settings.

Abstract: The Late Triassic Bolila Formation in the central Qiangtang Basin is a critical carbonate succession, yet its depositional age and reservoir‑forming mechanisms have long been contentious. This study presents an integrated sedimentological, detrital zircon U–Pb geochronological, carbon‑oxygen isotopic, and reservoir petrological investigation of the Quemudongda section. Detrital zircon ages constrain the deposition to 225.7–235.7 Ma (Carnian–Norian), correcting its previous Jurassic assignment. Stable carbon and oxygen isotope signatures (δ¹³C up to +4.0‰, δ¹⁸O as low as –14.3‰) corroborate the Late Triassic age and indicate a warm, humid paleoenvironment. The section reveals a steep‑rimmed platform‑margin association dominated by hexactinellid‑calcareous sponge reefs intercalated with seven slump‑breccia layers, recording three evolutionary stages from reef initiation to decline. Reservoir properties are controlled by the interplay of sedimentation, dolomitization, and fracturing. Early dolomitization generated intercrystalline porosity, but subsequent high‑temperature burial recrystallization produced xenotopic textures that severely reduced matrix porosity (average 2.8%). Tectonic microfractures provide the main permeability pathways (0.001–8.5 mD), resulting in a fracture–pore dual‑porosity system. Breccia dolostone exhibits significantly better physical properties (average porosity 3.71%, permeability 2.412 mD) than reef dolostone. The platform‑margin reef‑shoal complex, overlain by Bagong Formation source rocks, forms a favorable lower‑reservoir / upper‑source assemblage. The breccia dolostone–fracture overlap zone represents the sweet spot for hydrocarbon exploration. These findings offer new insights into carbonate platform‑margin evolution and provide a scientific basis for reservoir prediction in the Qiangtang Basin.

Abstract: We present a new whole-rock geochemical dataset for intrusive rocks of the late Variscan Serre batholith (Calabria, southern Italy), a well-exposed section of tilted con-tinental crust emplaced between ~305 and 292 Ma. The dataset includes major, trace and rare earth element (REE) analyses for 74 samples collected from the main plutonic units, ranging from tonalites and quartz-diorites at deeper structural levels to peraluminous granites at shallower levels, as well as leucosomes from associated migmatitic metase-diments. Analytical data were obtained using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). The dataset integrates new and previously published geochemical data into a con-sistent and reusable format, including sample locations (WGS84), lithological classification and stratigraphic attribution. Sampling sites are also provided as a downloadable geo-spatial (.kmz) file for visualization in GIS platforms. The dataset is made available as a supplementary Excel file. These data are intended to support a wide range of applications, including petro-genetic studies of granitoid magmatism and investigations of water–rock interaction processes in crystalline aquifers. The dataset represents a valuable resource for both fundamental and applied geoscientific research.

Abstract: With growing global REE demand, the investigation of cryptic clay-hosted rare earth element (REE) enrichment provides a better understanding of potential new prospects. This study is focused on novel REE enrichment (up to 1.38 wt.% TREO) identified in the regolith overlying the Doradilla Sn skarn prospect, northern New South Wales, Australia. The REE mode of occurrence was investigated through petrographic, field emission scanning electron microscopy (FE-SEM), micro-X-ray fluorescence (µ-XRF), and Laser Raman analyses. Secondary REE-bearing phosphate minerals are the dominant host of the REE in the regolith at Doradilla. The presence of water identified through Laser Raman confirms these minerals as rhabdophane-(La) (La(LREE,Ca)(PO₄)·_nH₂O), hosting most LREE, and churchite-(Y) (Y(HREE,Ca)(PO₄)·2H₂O), hosting most HREE. Through confirming the majority of REE being hosted in hydrated, and therefore, secondary minerals, this cryptic REE-enrichment is confirmed to be the result of secondary mineralization driven entirely by regolith-derived processes. This study highlights the importance of detailed mineral characterization in confirming the deportment of REEs in clay-hosted settings, and suggests that new protoliths (in this case a Sn skarn) have the potential to form significant, secondary REE enrichment in the overlying clay-hosted, regolith environment.