Geochemical characteristics and paleoclimatic significance of the Late Miocene-Pleistocene in the Sanhu Depression, eastern Qaidam Basin, Tibetan Plateau

Dual functionality of late-stage carbonized kerogen in ultra-deep petroleum systems: Geochemical characterization, molecular modeling, and resource implications

The Okinawa Trough is an active back-arc basin in the western Pacific Ocean located along a convergent continental margin. Although the presence of authigenic carbonates with specific morphological characteristics has been reported at a few sites, their distribution remains poorly understood because of the limited availability of geophysical and geochemical data from the northern Okinawa Trough. This study probes the geochemical characteristics of these authigenic carbonates and investigates their distribution using multibeam bathymetry, revealing a rough seafloor morphology developing on the western slope of the northern Okinawa Trough and extending more than 300 km in a slope-parallel direction. The geochemical analysis of authigenic carbonates recovered from multiple locations across this rough-morphology area reveals 13 C depletion and, thus, indicates that the constituent carbon was primarily sourced through the anaerobic oxidation of methane associated with fluid seepage activity. The Post-Archean Australian Shale–normalized rare-earth element patterns of the examined carbonates show notable enrichment of Y compared with Ho and Dy. The carbonates also exhibit positive correlations between Y/Ho and Y/Dy ratios, which fall between those typical of sediments and seawater. This finding indicates early diagenesis in an open system with substantial contributions from bottom seawater during carbonate precipitation. The wide range of Y/Ho ratios may further imply that the methane-rich fluids originated from a mixture of biogenic and thermogenic sources. The occurrence of methane-derived authigenic carbonates correlates with the distribution of high-backscatter-intensity areas and specific geological units. It thus indicates the widespread presence of carbonates along the western slope of the northern Okinawa Trough. • Widespread authigenic carbonates were recovered from the northern Okinawa Trough. • Carbon and oxygen isotope analyses were used to identify the origin of methane. • The carbonates occur widely and continuously in specific geological units.

Genesis of magnesite–talc–brucite deposits in Paleoproterozoic Mg-rich carbonate formations, Liaodong Peninsula, northeast China

The rapid transition from backyard to industrial livestock production has profoundly altered the geochemical characteristics of agricultural wastes, yet conventional risk assessment frameworks remain predominantly concentration-oriented and lack the capacity to resolve structural imbalances within the heavy metal suite. This study proposes a novel two-dimensional geometric fingerprinting framework to quantify the decoupling between pollution magnitude and structural distortion in livestock manure. A total of 204 manure samples were collected from a representative intensive farming region in the Sichuan Basin, Southwest China. Eight heavy metals and pH were analyzed, and concentrations were dynamically normalized using the pH-dependent thresholds defined in the Ministry of Ecology and Environment of the People's Republic of China standard GB 15618-2018. Two geometric descriptors were derived from radar projections of risk quotients: the comprehensive risk area (Sarea), representing cumulative pollution magnitude, and the coefficient of variation (CV), quantifying fingerprint distortion. Results revealed a significant expansion of pollution magnitude under industrial farming, accompanied by intensified structural imbalance, primarily driven by excessive Cu and Zn inputs. Principal component analysis further confirmed a clear structural divergence between backyard and industrial systems. Critically, no significant linear correlation was observed between Sarea and CV, demonstrating a stochastic decoupling between total load and geochemical structure. This dual-indicator framework reveals that pollution magnitude does not inherently predict structural distortion, highlighting the inadequacy of single-metric assessments. By integrating dynamic regulatory normalization with geometric topology, the study establishes a structural early warning paradigm for manure management.

This study presents a comprehensive geochemical and isotopic investigation of urban stream sediments draining into the Keban Dam Lake in Eastern Türkiye. A total of 15 sediment samples were collected along a ~35 km transect, spanning rural-to-urban transition zones. PAAS-normalised REE patterns revealed coherent light REE behaviour and positive Eu anomalies (Eu/Eu* = 1.57–2.01), except sample K8 (Eu/Eu* = 0.91), indicating contributions from plagioclase-bearing lithologies. Enrichment Factor (EF) calculations based on scandium normalisation showed notable enrichment in Li, Zr, Nb, and REEs, reflecting felsic source rocks and mineralogical sorting. Multivariate statistical analyses (PCA and HCA) revealed distinct groupings of elements associated with lithogenic sources (Be, Sc, and Y) and anthropogenic inputs (Li, Sn, and Rb). Spatial clustering of samples into rural, transitional, and urban zones supported this differentiation, suggesting increasing anthropogenic influence downstream. Sr isotopic data (87Sr/86Sr = 0.7045–0.7057) and Pb isotope ratios (206Pb/204Pb = 18.914–18.947) suggest dominantly geogenic control, with slightly more radiogenic signatures in urban sediments. These integrated geochemical and isotopic results provide the provenance model for the Keban catchment, highlighting how natural lithological sources and urbanisation jointly shape sediment composition and metal distribution. The findings also provide a useful geochemical baseline for environmental monitoring, sediment quality assessment, and sustainable watershed management in the Keban Dam Lake basin.

Paleoproterozoic granitoids of the Mount Isa Inlier record a prolonged history of crustal magmatism linked to the tectonic evolution of the North Australian Craton during assembly of the Nuna supercontinent. This study presents a lithogeochemical investigation of intrusions from the Dajarra region, in the southern Western Fold Belt, to constrain their geochemical characteristics, petrogenesis, and tectonic setting. The intrusions were emplaced at ca 1850–1650 Ma and correspond to four major magmatic episodes: the Kalkadoon, Argylla, Wonga-Burstall and Sybella igneous events. Thirty-three representative samples of plutons and associated dykes were analysed for whole-rock major and trace elements. The granitoids are dominantly felsic (SiO2, 62.6–76.7 wt%), with low MgO and TiO2 contents, high total alkalis and coherent fractionation trends consistent with extreme magmatic differentiation. Most samples are ferroan, alkalic-calcic to calc-alkalic and strongly peraluminous, whereas the Kalkadoon (KIE) sample is metaluminous. Trace-element patterns are characterised by enrichment in large ion lithophile elements and high-field-strength elements (HFSEs), pronounced negative Nb, Ti, Sr and Eu anomalies, and moderately to strongly fractionated rare earth element patterns. Distinct geochemical differences are observed between granitoid suites and across major structural boundaries, notably between Argylla intrusions east (AIE-E) and west (AIE-W) of the Rufus Fault. Many AIE-E, Wonga-Burstall and Sybella samples display elevated HFSE abundances and high zircon saturation temperatures, whereas AIE-W samples are HFSE-poor and exhibit lower temperatures, consistent with S-type affinities. On granite discrimination diagrams, most samples plot near the I- and A-type boundary and mainly within the A2 field, indicating derivation from reworked continental crust. This suggests that granitoid magmatism in the Dajarra region was dominated by partial melting of continental crust, with episodic mantle input required to achieve high melt temperatures. The magmatism occurred within a long-lived convergent margin system characterised by tectonic switching between contractional and extensional regimes during the Paleoproterozoic evolution of the Mount Isa Inlier.

ABSTRACT The intracontinental deformation is an essential element of the tectonic evolution of the Central Asian Orogenic Belt (CAOB) during the Late Mesozoic. Located along the Mid‐southern CAOB, the Zhusileng–Hangwula tectonic belt connects the Beishan Orogenic Belt and the Solonker Suture. However, the chronological constraints of Mesozoic history on this region remain unclear. Here, we presented field observations, geochemical characteristics and low‐temperature thermochronometry (apatite fission track, AFT) results from the Chaheilingashun area (northwestern Zhusileng–Hangwula tectonic belt) to constrain the regional tectonic history. The whole‐rock geochemical data indicate that the Middle Devonian Chaheilingashun monzogranite pluton is a (high‐K) calc‐alkaline S‐type granitoid. This pluton most likely formed in a postcollisional setting during the Middle–Late Devonian. New AFT data and thermal history modelling of the Chaheilingashun pluton suggest that the region experienced rapid cooling and exhumation events (135–133 Ma). The regional Mid–Late Jurassic contractional deformation (termed phase B of Yanshanian deformation) could have lasted until the earliest Early Cretaceous. Following this shortening event, regional extension was widespread in the mid‐southern CAOB, as evidenced by rift‐related magmatism, metamorphic core complexes and widespread concurrence of extensional basins. Therefore, we suggest that the Early Cretaceous tectonic transition (from contraction to extension) could have occurred at 133 Ma in the Zhusileng–Hangwula tectonic belt. In addition, this transition could have resulted from multiple factors related to the far‐field effects of oceanic plate subduction.

Sandstone of the Lower Cretaceous Luohe Formation is the main water inrush source in the Binchang Mining Area in the southwestern Ordos Basin. Its sedimentary environment and provenance features are critical for local coal development and safe mining. The Luohe Formation at Xiaozhuang Coal Mine comprises three vertical members: the lower member dominated by coarse- to medium-grained sandstones, the middle member mainly composed of fine-grained sandstones, and the upper member characterized by interbedded fine- to medium-grained sandstones and sandy conglomerates. This subdivision newly identifies a complete hydrodynamic evolutionary cycle of depositional environments from high-energy to low-energy and back to high-energy conditions. Integrated petrographic observations and analyses of major and rare earth elements first confirm that the tectonic affinity of the Luohe Formation progressively shifted from a passive continental margin to an active continental margin, accompanied by a corresponding transition in sediment provenance from the North China Craton to a magmatic arc source region. Trace element compositions precisely indicate that the Luohe Formation was deposited in a fluvial freshwater environment under hot, arid, and oxidizing conditions, thus providing new constraints on the paleoenvironmental evolution of the region.

From the 2018–19 Antarctic Search for Meteorites (ANSMET) season, eight polymict, basaltic lunar regolith breccias were recovered from the Dominion Range (DOM). This study examines DOM 18543,9, a clast-poor breccia (<10%) containing clasts of basalts, gabbros, impact melt breccias, three-phase symplectites and one microbreccia containing a Ferroan Anorthosite (FAN)-derived, anorthositic granulite. All clasts and mineral fragments are set in a glassy matrix that contains glassy melt veins, pockets and impact glass spherules. Pyroxene and olivine Fe/Mn systematics are consistent with a lunar origin. Pyroxenes are augites and pigeonites, olivines are predominantly fayalitic (Fa 85–99 ) and plagioclase is typically anorthitic (An 93–99 ). Pyroxene, ilmenite and olivine compositions are consistent with derivation from a compositionally evolved, low-Ti basaltic magma and represent the relatively late stages of fractionation. Textural and geochemical characteristics are similar to those of the YAMM group, indicating a potential shared source from an ancient, low-Ti, KREEP (potassium, rare-earth elements and phosphorus)-poor lava flow in a mare terrane where feldspathic material is locally available. While some characteristics are shared with an unnamed crater within the Schickard crater, characterization of paired meteorites within the DOM clan, alongside cosmic ray exposure dating and integration of remote-sensing observations, is required to refine the petrological framework of these recently discovered lunar samples.

ABSTRACT This study presents an integrated organic geochemical, petrological characteristics, biomarker, and elemental compositions of shale facies of Paleocene–Eocene Patala Formation. The dataset consists of an outcrop section and an exploratory well (Manzalai‐1) situated in the Kohat Plateau, Upper Indus Basin (North Pakistan). This work aimed to understand organic matter (OM) input and paleoenvironmental settings during the Late Paleocene time and their effect on organic carbon‐rich amassing in Patala shale facies. Geochemical analysis shows that most of the Patala shale sediments are characterized by >1–3.25 wt.% total organic carbon (TOC), demonstrating good OM accumulation under low‐oxygenated environmental settings. During deposition of Patala shale facies, the low‐oxygenated environmental settings (mainly anoxic to euxinic) of water column facilitated preservation of OM. It is revealed by comparatively low pristane (Pr)/phytane (Ph) ratio between 0.79 and 2.38 and relatively higher concentration of vanadium (V) compared to nickel (Ni), with high V/Ni ratio reaching 11 and V/(V + Ni) values as high as 0.92. The current study also investigated the source and origin of OM contribution into the Patala shale facies during deposition. The characteristics of hopane, tricyclic terpane, and sterane biomarkers provide evidence that the Patala shale facies contains mixed OM of planktonic bacteria with terrigenous plant inputs. The finding is confirmed by the presence of marine microorganisms such as coccolithophore plankton and fossilized bacteria, as indicated by scanning electron microscopy (SEM) results. Paleoclimatic proxies demonstrate that the climatic conditions were warm and humid during the Paleocene–Eocene thermal maximum (PETM) event. The PETM extended warm‐water episodes led to eutrophic conditions, which resulted in intensified subaerial weathering and nutrient mass influx, thereby contributing to rise in marine primary bioproductivity within the photic zone. Consequently, the high bioproductivity concomitant with active OM preservation promoted amassing of organic carbon in Patala shale facies during deposition of the Paleocene–Eocene time.

The North Qilian Orogenic Belt is a key region for understanding the evolution of the Paleo-Asian Ocean and continental accretion. The Dachadaban area preserves a complete ophiolite suite and coeval granitoid intrusions. Zircon and apatite U–Pb geochronology, whole-rock geochemistry, and Sr–Nd isotopic analyses were conducted on intermediate–felsic intrusions from this area. Zircon and apatite ages of 512–504 Ma (Late Cambrian) record a regional magmatic pulse. The rocks are metaluminous to weakly peraluminous, high-K calc-alkaline, enriched in LILEs (Rb, Th) and depleted in HFSEs (Nb, Ta, Ti), with right-inclined REE patterns and moderate negative Eu anomalies, typical of island-arc granitoids. Initial 87 Sr/ 86 Sr ratios (0.7205–0.7286), ε Nd (t) values (−9.7 to −6.4), and T DM2 ages (2019–1751 Ma) indicate magmas derived mainly from partial melting of Paleoproterozoic crust with ca. 20%–30% mantle input. Zircon Ti-thermometry indicates crystallization temperatures ranging from approximately 692 °C–826 °C, accompanied by a shift in oxygen fugacity from relatively oxidized to reduced conditions and a concomitant decrease in water content. Apatite and whole-rock geochemical characteristics collectively indicate an evolution from I-type to A-type granitoids. Tectonic discrimination suggests that this magmatism occurred in a back-arc extensional setting driven by slab rollback during waning subduction, rather than in a post-collisional environment. Earlier-formed I-type granites underwent dehydration melting under thermal perturbation and decompression, producing late-stage A 2 -type granites, marking a transition of the North Qilian Orogen from convergence to extension at ca. 512–503 Ma.

Geochemistry and mineral potential of Arum and environs, North Central Nigeria, was carried out to evaluate and characterize the major and trace elements composition in the rocks and stream sediments of the area. Sixteen rock samples from four lithologies and eighteen stream sediments were collected at strategic locations. The samples were geochemically analyzed for major and trace elements using X-ray fluorescence. The silica concentrations in the pegmatite and granodiorite range from 76.0 to 79.95 weight percentage (wt%) and 74.09 to 76.01 weight percentage (wt%), respectively, according to the analytical results, which showed that both minerals are extremely siliceous. All of the lithologies in the study area exhibit a slightly consistent concentration of Al2O3, with the ranges being 13.48 to 15.06 in fine to medium grain granite gneiss, 14.65 to 15.91 in medium grain banded gneiss, 13.26 to 14.3 weight percent (wt%) in granodiorite, and 14.26 to 14.65 weight percent (wt%) in pegmatite. The TAS plot of silica saturation index indicates that Arum rocks are granitic, and the aluminum saturation index indicates that Arun rocks are primarily peraluminous. The geochemical concentration shows the spatial distribution and enrichment. The bar-chart concentration plots revealed an uneven anomalous concentration of thorium (Th), tantalite (Ta), niobium (Nb), tin (Sn), and rubidium (Rb) in ppm, compared to their respective background concentration, which revealed a positive anomalous concentration. Arum shows allochthonous mineralization that is structurally controlled and can be regarded as been mineralized in Th, Nb, Sn, U, and Ta.

Mercury (Hg) decontamination in active and decommissioned mining areas is a difficult task since Hg may affect environmental matrices and man-made materials. Despite its toxicity as an inorganic form being rather limited with respect to organic compounds (e.g., methyl-Hg), severe effects to human health and ecosystems are recognized. In this work, we review the geochemical activities carried out in the last 13 years at the Abbadia San Salvatore (AbSS) mining and production area. This site belongs to Mt. Amiata (Tuscany, central Italy), which is considered the third-largest Hg-district in the world. Air, water, soil and man-made materials within the AbSS area were investigated to verify to what extent such matrices were affected by Hg contamination. The geochemical investigations are used as important tools to proceed with specific remediation operations of edifices, mining structures and machineries as well as the local groundwater system. To the best of our knowledge, restoration of decommissioned areas affected by Hg contamination at a large scale, such as the AbSS exploitation and production site, is rather uncommon. Currently, the remediation activities in the AbSS area are going on and they are expected to be concluded at the end of 2026 or the beginning of 2027, when the former mining area will turn into a public archeometallurgical museum.

Studies have been made of the Abai alkaline rocks massif, located in the northeastern part of the ChingizTarbagatai zone of Eastern Kazakhstan. The Chingiz-Tarbagatai zone of Eastern Kazakhstan is located in the western part of the Central Asian Orogenic Belt (CAOB), the lithospheric evolution of which continued during the Paleozoic and was associated with the basin closure in the system of the Paleoasian Ocean. The 9 km² massif is characterized by an isometric shape with a clearly defined concentric zonal structure and represents a multiphase intrusion composed of several varieties of syenite. Potassium feldspar is the most prevalent mineral in syenite, while plagioclase, pyroxene (5 to 15 vol. %), and amphibole (5 to 20 vol. %) are less common. Most of the massif is composed of nepheline syenite rocks containing 5–10 vol. % of nepheline. Accessory minerals include apatite, zircon, and ilmenite. Studies of mineral composition and geochemical characteristics of the rocks revealed that the syenites formed during the evolution of a single magma melt composed of alkali-syenite or monzonite. This magma was formed probably as a result of primary alkaline-mafic magma differentiation. The U-Pb LA-ICP-MS dating of magmatic zircon grains for the first time yielded a relibale rock age estimate of 401–398 Ma, which corresponds to the Emsian stage of the Early Devonian. This refutes the previously accepted ideas about the Early Permian age of the massif and its intraplate geodynamic nature. When the data on the composition and age of the massif are compared with the data on the geological evolution of the region, it is apparent that the Abai syenite massif formation is related to the extensional processes in response to subduction of the Junggar-Balkhash oceanic lithosphere underneath the Chingiz-Tarbagatai zone.

Geochemical characterization of groundwater and its suitability for drinking in the hard rock terrain of the Karaipottanar sub basin Southern India

Geochemical characteristics of magmatic phases in Chumathang granitoids, NW Ladakh Himalaya, India: implications for tectonic setup and magmatic evolution of granites

The paper presents data on native gold from the Shamanikha-Stolbovaya ore region of the Prikolymskoe uplift in the Northeastern Russia. Gold mineralization developed in the region, taking into account its geochemical characteristics and data on the composition of microinclusions within it, can be assigned to the type of gold deposits related to reduced granitoids. Its characteristic zonality is expressed in change of gold-hematite-pyrite mineralization to gold-polysulfide and to gold-silver-polysulfide ones. These mineral assemblages are characterized by native gold of predominantly high, medium, and low fineness and by high frequency and elevated contents of copper, lead, bismuth, and iron, respectively. The gold-polysulfide mineralization played the main role in feeding the gold placers. Using combination of the cluster analysis, correlation analysis, and principal component methods allow us to reveal an indicative significance of the manganese-arsenic-tellurium-bismuth-palladium-lead and iron-bismuth-lead-nickel-arsenic-manganese geochemical types of native gold with a general gold-rare metal character of the ore-forming systems. Native gold of the Shamanikha-Stolbovaya ore region diff in the role of the geochemical types from the native gold derived from gold-quartz objects of the Central Kolyma and from porphyry molybdenum-copper occurrences of the Topolevaya-Khetachan ore region.

To elucidate the sedimentary environment and provenance background of the Wufeng–Longmaxi Formation in the Shuiquan area of Hefeng, Hubei Province, geochemical analyses were conducted on samples collected from an observed profile. The results indicate that the sedimentation of the Wufeng Formation occurred under predominantly cold and dry climatic conditions, whereas the Longmaxi Formation was characterized by a warm and humid climate. The ratios of Ba/Al and Ba(bio) suggest that the ancient productivity at the base of the Longmaxi Formation was relatively high. During its deposition, the Wufeng Formation experienced an oxidizing to sub-oxic environment, while the Longmaxi Formation exhibited an overall sub-oxic environment. Variations in rare earth elements indicate that the sedimentation rate of the Wufeng Formation was higher than that of the Longmaxi Formation; however, a layer with a significantly slow sedimentation rate is present at the base of the Longmaxi Formation; According to the U/Mo covariance model, the sedimentary environment of the Longmaxi Formation is characterized by a strong retention of water bodies. The characteristics of trace elements and rare earth element compositions and their ratios indicate that the material sources primarily originate from the upper crust, exhibiting a relatively homogeneous source with the main parent rock being felsic granite. The tectonic background of the source area is predominantly characterized by an active continental margin, while also displaying some features typical of continental island arcs.

Anticipating the environmental and societal consequences of climate-driven permafrost thaw requires knowledge of terrain and subsurface conditions, which prove challenging to obtain at spatial scales necessary for rigorous prediction and decision-making. Analysis of a systematic inventory of permafrost landforms across northwestern Canada demonstrates that landform assemblages co-develop with ecosystems, distinguishing fundamental permafrost properties across a continental-scale ecoclimatic gradient (106km2) and among finer-scale ecological regions (103 to 104 km2). This approach quantifies variation in geological and climatic legacies and delineates the diverse consequences of thaw. Here we show that permafrost landsystems, defined by characteristic landform assemblages, express spatial variation in soil, ground ice, geochemical, and carbon characteristics, enabling these intrinsic conditions to be inferred at regional scales through integrated mapping and analyses. Permafrost landsystems also provide a conceptual framework to inform predictions of thaw-driven change, and to formulate, share, and apply permafrost knowledge across scales, disciplines, and ways of knowing.