Search Results (140)

Volcanic rocks of the Qi’eshan Group, which are widely distributed in the Dananhu arc of the Eastern Tianshan, NW China, have long been debated in terms of their formation age and tectonic setting. In this study, we conducted an integrated study of U-Pb apatite geochronology, whole-rock major and trace element geochemistry, in situ major element analyses of clinopyroxene, and “Rhyolite-MELTS” thermodynamic modeling on the basalts from the Qi’eshan Group. Geochronological data show that the weighted mean of ²⁰⁶Pb/²³⁸U ages of apatite is 329 ± 10 Ma. The basalts belong to the tholeiitic series and are characterized by enrichment in large ion lithophile elements (LILEs), depletion in high field strength elements (HFSEs), and enrichment of light rare earth elements (LREEs) relative to heavy rare earth elements (HREEs) with weak negative Eu anomalies. They were derived by partial melting of garnet-spinel lherzolite in a depleted mantle source metasomatized by subduction-related fluids, followed by fractional crystallization of spinel, olivine, and clinopyroxene. Clinopyroxene is dominated by augite, characterized by high Mg and Ca contents and low Al and Na contents. Machine-learning-based thermobarometry indicates that clinopyroxene crystallized at temperatures of 1027–1033 °C and pressures of 1.1–1.6 kbar. “Rhyolite-MELTS” isobaric crystallization simulations suggest that mantle-derived magma, with an initial water content of 4 wt.% and oxygen fugacity of FMQ, can generate melts compositionally similar to the volcanic rocks of the Qi’eshan Group through fractional crystallization at a pressure of 1.5 kbar. Combined with previous studies, we propose that the Qi’eshan Group basalts formed in an extensional arc setting related to southward rollback of the northward-subducting Kanguer oceanic slab, which caused asthenosphere upwelling and lithospheric extension, thereby promoting partial melting of the subduction-metasomatized mantle. Our data provide new insights into the Carboniferous rollback of the Kanguer oceanic slab in the northern part of the Eastern Tianshan. Full article

Pegmatite dikes are important prospecting indicators for rare-metal deposits, whereas traditional methods for pegmatite dike identification are constrained by the limited capability of human visual interpretation to capture information from remote sensing imagery, resulting in low identification accuracy and efficiency. In recent years, global research on semantic segmentation of different surface features and remote sensing-based mineral exploration using deep learning methods and high-resolution remote sensing imagery has made significant progress; however, studies on surface-exposed geological bodies such as pegmatite dikes remain highly insufficient. To address the key problem of efficiently identifying pegmatite dikes in remote sensing imagery, this study proposes an improved model based on UNet++, termed GAD-UNet++. In the field of remote sensing geology, this study constructed a pegmatite dike semantic segmentation dataset based on high-resolution RGB imagery by using 0.66 m RGB imagery for visual delineation and ZY1F hyperspectral data for spectral constraint and label refinement; on this basis, semantic segmentation of surface pegmatite dikes in the Yilanlike area of the South Tianshan Mountains, Xinjiang, was conducted using RGB remote sensing image patches as model input. Specifically, because pegmatite dikes are small targets characterized by slender structures, indistinct boundaries, and sparse regional distribution, this study introduced a lightweight feature extraction structure (GhostNetV2) and a long-range dependency attention module (DFC) at the encoder stage, and further incorporated the Coordinate Attention module (CA) to enhance spatial localization and boundary representation of the targets. Finally, focal cross-entropy loss and a deep supervision strategy were adopted to improve the accuracy of semantic information extraction for pegmatite dikes, as well as the training stability and segmentation accuracy under class-imbalance conditions. The results show that the proposed model achieved an mIoU of 93.11% and an F1-score of 94.95% on the test set. Compared with existing semantic segmentation models, the proposed model achieved superior performance in both identification accuracy and computational efficiency for pegmatite dikes. In addition, this study delineated 18 potential pegmatite dike enrichment zones in the Yilanlike area, providing technical support for remote sensing-based rare-metal prospecting and geological interpretation in the study area. Full article

The South Tianshan Orogenic Belt, as the southernmost part of the Central Asian Orogenic Belt (CAOB), records the final closure of the Paleo-Asian Ocean and the subsequent collision between the Tarim Craton and the Central Tianshan–Yili Block. However, the timing of this collision and the subduction polarity of the South Tianshan Ocean remain controversial. In this study, we present integrated detrital zircon U-Pb geochronology, Lu-Hf isotopes, and rare earth element (REE) geochemistry for Carboniferous to Permian sedimentary rocks from the northern Tarim Craton and the South Tianshan Orogenic Belt. Our results show that the detrital zircon age spectra are dominated by peaks at ~290 Ma, ~420 Ma, ~640–620 Ma, ~840–830 Ma, and ~1900–1800 Ma, with a notable scarcity of 380–310 Ma zircons. The ε_Hf(t) values of Paleozoic zircons are predominantly negative, consistent with the magmatic records of the Tarim Craton but distinct from those of the Central Tianshan–Yili Block. These provenance signatures indicate that most of the Carboniferous–Permian sedimentary rocks were derived from the Tarim Craton, with only a minor mixed-source component (e.g., the Balikelike Formation silty limestone) involving the Central Tianshan–Yili Block. The absence of significant 380–310 Ma detrital zircons in the foreland strata, together with the passive margin affinity of the northern Tarim, supports northward subduction of the South Tianshan Ocean. A sharp decrease in detrital zircon r_Dz values and crystallization temperatures at ~310 Ma signals a tectonic transition from convergence to collision, constraining the final closure to the Late Carboniferous (~310 Ma). Furthermore, crustal thickness estimates based on zircon Eu anomalies remain stable at ~60 km across the subduction and collision stages, suggesting limited tectonic shortening and thus a soft collision. Full article

The formation of tectonic–magmatic–sedimentary processes during the Permian in the Beishan region represents a highly debated research topic along the southern margin of the Central Asian Orogenic Belt and even globally: does it mark the final subduction and amalgamation of the Paleo-Asian Ocean, or does it instead represent rifting superimposed upon an earlier orogen? New field observations combined with geochemical analyses reveal that the Liuyuan area is dominated by Early Permian basalts, associated with a rifting sedimentary sequence. During the Mid–Late Permian, gabbro–rhyolite associations were emplaced, accompanied by minor lacustrine sedimentation. The late stage was characterized by minor granitic intrusions or dikes with adakitic affinities, culminating in the emplacement of lamprophyre dikes. The basalts and gabbros in the Liuyuan area display mantle-derived geochemical signatures, with compositions intermediate between MORB and OIB. The exposed Permian basalt–rhyolite bimodal magmatic suite represents a genetically integrated rift-related rock series. Geochemical data from the Ordovician granites and schists within the belt reveal adakitic characteristics, implying that the Permian granitic rocks largely represent remelting products of these early granitic and schistose protoliths. Collectively, the lithological characteristics and magmatic associations clearly demonstrate that the tectonic setting during the Early Permian corresponded to a post-collisional extensional environment superimposed upon the early Paleozoic orogenic belt (Caledonian Huitongshan ophiolite–arc accretionary orogen), which subsequently underwent tectonic inversion to form the present-day orogenic structure. This paper proposes a theoretical model wherein the bimodal magmatic suite was generated by the upwelling of enriched asthenospheric mantle material, providing the driving mechanism for rifting. It formed within a post-collisional extensional environment developed over a complex pre-existing orogenic belt and was subsequently inverted, forming the current tectonic belt—a typical intracontinental Pyrenees-type orogeny. Full article

The Mesozoic dykes in the Xingcheng area of western Liaoning Province in China were investigated through an integrated study involving zircon U–Pb geochronology, whole-rock geochemistry, and zircon Hf isotopic compositions to elucidate their emplacement phases, petrogenesis, and tectonic setting. The dykes are classified into two groups: felsic (granite porphyry, granite aplite) and mafic (diabase, lamprophyre). Emplacement occurred in four discrete phases: Late Triassic (229–212 Ma), Early Jurassic (ca. 179 Ma), Late Jurassic (162–152 Ma), and Early Cretaceous (133–102 Ma). The felsic dykes are characterized by high SiO₂ and alkali contents, low TFeO and MgO abundances, and belong to the high-K calc-alkaline I-type granite series. The mafic dykes exhibit low SiO₂, elevated MgO, and high Na₂O contents, displaying both alkaline and calc-alkaline affinities. Both dyke suites are consistently enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs), and depleted in heavy rare earth elements (HREEs) and high field-strength elements (HFSEs). Zircon ε_Hf(t) values for the felsic dykes range from −22.3 to −7.4, corresponding to two-stage model ages (T_DM2) of 2613–1729 Ma, indicating derivation from partial melting of Neoarchean to Paleoproterozoic crustal material. Late Jurassic mafic dykes yield ε_Hf(t) values between −27.8 and −20.2, consistent with an origin from partial melting of enriched lithospheric mantle. In contrast, Early Cretaceous mafic dykes display a bimodal ε_Hf(t) distribution (−12.9 to −9.5 and +4.3 to +8.4), suggesting a predominant enriched mantle source with variable inputs from depleted mantle components. Integrated with regional tectonic reconstructions, the data indicate that the Xingcheng area evolved within a post-collisional extensional regime following the amalgamation of the North China Craton and the Central Asian Orogenic Belt during the Late Triassic. The Jurassic magmatic pulses are attributed to an active continental margin setting associated with subduction of the Paleo-Pacific Plate, whereas the Early Cretaceous phase reflects regional extension triggered by rollback of the subducting Paleo-Pacific slab. Full article

The Chutuan and Jiashan fluorite deposits are situated in the Donghai–Linshu area within the southwestern segment of the Sulu ultrahigh–pressure metamorphic belt. Both deposits share similar mineralization characteristics, with fluorite veins strictly controlled by fault structures and associated with mineral assemblages comprising fluorite, barite, quartz, and calcite. Two mineralization stages have been identified in both deposits: Stage I (quartz–fluorite–barite stage), representing the main ore–forming event, and Stage II (quartz–barite–calcite stage). This study focuses on integrated geochemical and geochronological analyses of fluorite from Stage I, providing new constraints on the genesis and metallogenic processes of these deposits. Direct Sm–Nd isotopic dating of fluorite yields an isochron age of 104 ± 16 Ma, indicating that mineralization occurred during the late Early Cretaceous. Fluid inclusion and stable isotope studies reveal that the ore–forming fluids constitute a complex hydrothermal system characterized by a wide temperature range (112–324 °C) and variable salinities (0.18–21.87 wt% NaCl eq.). The H–O isotopic compositions exhibit a distinct latitudinal trend, supporting a dominant meteoric water component. However, the presence of high–temperature, high–salinity fluid inclusions, along with a shift in some δD values towards the magmatic water field, suggests episodic mixing between meteoric water and deep–seated magmatic–hydrothermal fluids. Sr–Nd isotopic data (⁸⁷Sr/⁸⁶Sr = 0.711785–0.713424; εNd(t)= −27.7 to −27.5) potentially demonstrate that the ore–forming materials (Ca and REEs) were not derived from coeval magmatic rocks. Instead, they were primarily leached from the Precambrian Donghai Group metamorphic complex through extensive water–rock interaction. Based on these findings, the Chutuan and Jiashan deposits are classified as hydrothermal vein–type systems. Fluorite precipitation was governed by a combination of fluid cooling, water–rock interaction, and fluid mixing. Finally, a metallogenic model is established, offering important insights into the genesis of fluorite mineralization in the Sulu Orogenic Belt and analogous geological settings in eastern China. Full article

With the growing demand for strategic metals and the gradual depletion of traditional metal ore deposits, coal and coal-bearing strata are regarded as potential sources of rare metals; consequently, research into the characteristics of associated elements in coal-bearing strata has become one of the primary avenues of searching for new alternative resources. To investigate the sedimentary environmental characteristics and controlling factors of the coal-bearing strata along the southern margin of the Junggar Basin, coal seams 9–15 of the Xishanyao Formation in Sulphur Gully (Early Middle Jurassic) were selected as the subject of this study. This study employed analytical techniques including industrial analysis, total sulphur analysis, X-ray powder diffraction (XRD), X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) to determine the mineralogical and elemental geochemical characteristics of coal samples from Seylangou mining area, specifically from coal seams 9–15 and their overlying and underlying strata. Based on analyses of elemental ratios such as Al₂O₃/TiO₂, Sr/Ba, Rb/Sr, Ni/Co and V/(Ni + V), the source of material during the deposition of this deposit was identified, and the characteristics of the depositional environment, as indicated by palaeosalinity, palaeoclimate and redox conditions, were revealed. The results indicate that the macroscopic coal-rock types of coal seams 9–15 at the Sulphur Gully Coal Mine on the southern margin of the Junggar Basin are predominantly semi-dull to dull, with small amounts of filamentous coal and lustrous coal. The average proportion of the vitrinite group in the coal is 42.75%, the inertinite group is 51.40%, and the liptinite is 2.25%. The average content of inorganic matter in the coal is 3.60%, and the average maximum reflectance of the vitrinite group is 0.651%. The coal represents a transitional stage from low-rank to medium-rank coal, corresponding to a metamorphic stage of Grade I–II. The coal is classified as a bituminous coal with medium total moisture, very low ash, medium-volatile matter, medium-to-high fixed carbon and very low sulphur. The minerals in the coal seam are predominantly kaolinite, calcite and quartz. The major elements in the ceiling of the coal seam are dominated by SiO₂, followed by Al₂O₃; the coal itself is dominated by CaO, SiO₂ and Al₂O₃; and the base plate of the coal seam is dominated by Al₂O₃. The trace elements Cs and Bi are relatively enriched in the coal seam ceiling; Sr is relatively enriched in the coal; whilst Li, Cr and other elements are highly enriched in the coal seam base plate. The source rocks of the coal and the roof consist of deposits of felsic igneous rock (dacite), whilst the source rocks of the floor consist of deposits of intermediate igneous rock (andesite). The depositional environment ranges from marine brackish water at the base to transitional slightly brackish water and then to terrestrial freshwater at the top; the depositional climate was cold and arid, and the depositional environment was oxidising. This study provides valuable insights for further research into the elemental geochemical characteristics, sediment sources and depositional environments of the Xishanyao Formation coal seams in Liuhuangou, Xinjiang. Full article

The Arganaty Massif in the Eastern Balkhash region (Kazakhstan) is located in a key sector of the Central Asian Orogenic Belt, but its petrogenesis and relationship to neighboring Late Palaeozoic intrusions remain poorly constrained. This study presents the first U–Pb zircon age and whole-rock geochemical data for the Arganaty granites, combined with a comparison with massifs of the Northern Balkhash region and Alatau Mountains (East Kazakhstan and Western Xinjiang, NW China). The Arganaty granites have a concordant U–Pb age of 281.5 ± 2.1 Ma. They are high-K calc-alkaline, metaluminous to slightly peraluminous I-type granites with low Mg# (0.22–0.33) and Nb/Ta ratios (10.2–17.3). Geochemical comparison indicates close affinity to the Lepsy complex intrusions and eastern plutons of Alatau mountains, rather than to the Katbar complex of Northern Balkhash. The new age and geochemical data show that the Arganaty granites formed in a post-collisional setting after the closure of the Junggar–Balkhash Ocean. Their mixed crust–mantle signature and depth estimates (~30 km) are consistent with lower crustal melting triggered by slab break-off. These results clarify the post-collisional magmatic evolution of the region and contribute to the understanding of Late Palaeozoic crustal growth in the CAOB. Full article

Northeast China, situated in the eastern Central Asian Orogenic Belt (CAOB), marks the terminal closure zone of the Paleo-Asian Ocean (PAO) (eastern segment). At present, due to extensive Quaternary cover, the structural deformation characteristics and deep structure of the Solonker Suture Zone in the east of the Nenjiang–Balihan fault remain poorly constrained, which limits our understanding of the tectonic evolution of the PAO. This study integrates deep seismic reflection (DSR) and magnetotelluric (MT) sounding profiles to investigate the crustal structural, sedimentary framework, and tectonic evolution of the oceanic and continental crusts along the western slope of the Songliao Basin. Two regional detachment surfaces (D1 and D2) were identified. The D2 interface demarcates the upper crust’s basal boundary, overlain by multiple high-amplitude monoclinic reflections. The area below the D2 interface exhibits a network structure of arcuate and variably oriented reflections, indicating a dual-layered orogenic structure. The upper crust exhibits distinct structural domains defined by strongly contrasting monoclinal reflections: north-dipping, low-resistivity zones in the southern sector and south-dipping, high-resistivity zones in the northern sector. These oppositely oriented reflections have been interpreted as marking an Early Paleozoic accretionary wedge and oceanic island arc, respectively. Interposed between these opposing structural domains, the Paleozoic to Early Mesozoic forearc basin sequences are preserved, with a pre-Middle Permian oceanic basin identified north of the study area. By integrating characteristics of seismic reflection sequences with regional geological data, this paper clarifies the processes of closure and collision at the northern margin of the PAO (Eastern Segment). Full article

Platinum group elements (PGE) are six rare highly siderophile metals which have similar chemical characteristics and occur together in mineral deposits: platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), iridium (Ir) and osmium (Os). In nature, they tend to exist in a metallic state or bond with sulfur and arsenic and occur as trace accessory minerals predominantly in mafic and ultramafic rocks. High industrial demand together with their scarcity in crustal rocks has been reflected in their inclusion in 2025 US Government’s List of Critical Minerals, European Union’s List of Critical Raw Materials and Mongolian List of 11 Critical Minerals. Although Mongolia is not currently a producer, it hosts four types of potentially economic PGE deposits: (1) Podiform chromitites associated with ophiolites; (2) Ni-Cu-PGE sulfide mineralization of rift-related mafic–ultramafic intrusions; (3) Alaskan–Uralian type arc related zoned mafic–ultramafic intrusions; and (4) Placers. Particularly promising are Permian Ni-Cu-PGE sulfide bearing mafic–ultramafic intrusions of the Khangai large igneous province which bear resemblance to mineralized Permian intrusions in Russia (e.g., Norilsk-Talnakh) and N.W. China (e.g., Kalatongke; Tarim basin). In addition, sub-economic ophiolite-hosted PGE mineralization can be extracted as a by-product during chromite mining. There is also the potential for PGE recovery as a by-product in existing gold placer operations in areas hosting ophiolitic massifs and Alaskan–Uralian type intrusions. Mongolia is a promising frontier for PGE exploration and mining. Full article

The application of multi-cycle steam stimulation in heavy oil reservoirs frequently alters reservoir properties, influencing the effectiveness of the stimulation and subsequent development strategies. The inherent heterogeneity of strata, characterized by distinct sedimentary facies rhythms, leads to differential patterns of property evolution. Therefore, understanding facies-controlled property variations during steam stimulation is essential for optimizing recovery strategies. This study integrates 1D core experiments with 3D geological modeling to dynamically simulate the stimulation process, enabling a comprehensive multi-scale analysis. The results show the following: (1) Both sedimentary rhythms exhibit progressive increases in porosity and permeability with successive cycles until reaching stabilization plateaus, with the uniform rhythm stabilizing earlier than the coarsening-upward rhythm. (2) 3D simulations reveal a predominant increasing trend in porosity and permeability after multi-cycle stimulation, albeit with localized reduction zones. (3) Multi-scale analysis indicates that, during the early stage (cycles 1–9), the underwater distributary channel microfacies undergoes more rapid property changes and achieves a greater cumulative increase in porosity and permeability. Conversely, during the later stage (cycles 10–30), the mouth bar microfacies demonstrates faster property alterations and a larger cumulative enhancement. This facies-specific, time-dependent understanding provides critical insights for tailoring steam stimulation strategies in heterogeneous heavy oil reservoirs. Full article

In this study, shale samples with diverse lithofacies from the Lower Silurian Longmaxi Formation in the Fuling Field were investigated to evaluate the variations in pore characteristics and methane adsorption capacity (MAC) of different shale lithofacies. A set of experiments were performed, such as total organic carbon (TOC) content, X-ray diffraction (XRD), field emission–scanning electron microscopy (FE-SEM), low-pressure gas (CO₂/N₂) adsorption, and high-pressure methane adsorption. Combined with TOC content and mineral composition, three types of shale lithofacies were identified, including organic-rich (OR) argillaceous-rich siliceous (S-3) shale lithofacies, organic-moderate (OM) argillaceous/siliceous mixed (M-2) shale lithofacies, and organic-lean (OL) siliceous-rich argillaceous (CM-1) shale lithofacies. Through detailed comparative analyses, we found that OR S-3 shales possess the maximum TOC content, the most developed heterogeneous organic micro-mesopores, the largest pore volume (PV), and the highest pore surface area (PSA); consequently, they display the strongest MAC. Conversely, OL CM-1 shales have the lowest TOC content and the highest clay content, and thus the smallest PSA and the poorest methane adsorption performance. In conclusion, considering the excellent gas storage potential, sustained shale gas production, and brittle response to hydraulic fracturing, OR S-3 shales are superior to shale gas exploration and exploitation compared with OM M-2 and OL CM-1 shales. Full article

The southern Central Asian Orogenic Belt (CAOB) underwent a major Early Paleozoic tectonic transition, yet its timing and mechanisms remain unclear. We present zircon U-Pb-Hf, whole-rock geochemical, and Sr–Nd isotopic data for newly identified Early Silurian (ca. 439–431 Ma) granitoids from the Liuyuan area of the southern Beishan Orogenic Belt. These high-silica, high-K calc-alkaline intrusions not only show arc-like trace-element patterns but also display elevated Ga/Al ratios and enriched Sr–Nd isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.7158–0.7189; ε_Nd(t) = −4.6 to −3.9), consistent with aluminous A₂-type granites derived mainly from ancient crust. Their heterogeneous zircon ε_Hf(t) values (−6.3 to +3.7) suggest a minor, localized input from mantle-derived mafic magmas superimposed on the dominant crustal signature. Integrating regional metamorphic constraints, we interpret this magmatism to have formed during the transition from oceanic subduction to incipient collision/continent involvement and subsequent post-subduction extension, plausibly triggered by slab break-off at the slab root (ocean–continent transition). Slab-window-related asthenospheric inflow and localized thermal perturbation could have promoted high-temperature crustal melting and facilitated Early Silurian crustal reworking in the southern CAOB. Full article

The Hatu region in the Western Junggar, Xinjiang, is one of the most significant gold metallogenic concentration areas in China. Gold mineralization is primarily controlled by several parallel NE-trending strike-slip faults and Late Paleozoic granitic plutons, accompanied by multiple stages of hydrothermal activity. To enhance the objectivity and accuracy of mineral prospecting prediction, this study develops an integrated forecasting framework that combines multi-source remote sensing datasets with machine learning techniques. Alteration anomalies related to iron staining and hydroxyl-bearing minerals are extracted from ASTER data, alteration mineral mapping is performed using GF-5 hyperspectral imagery, and Landsat-9 data is used for structural interpretation to refine the regional metallogenic framework. On this basis, these multi-source remote sensing products are then integrated to delineate five prospective metallogenic areas (T1–T5). Subsequently, a Random Forest (RF) model optimized by the Grey Wolf Optimizer (GWO) algorithm is employed to quantitatively integrate key evidence layers, including alteration, structure, and geochemistry, for estimating mineralization probability. The results show that the GWO-RF model effectively concentrates anomalous areas and identifies two high-confidence targets, Y1 and Y2, both with mineralization probabilities exceeding 0.8. Among them, the Y1 target is associated with the Bieluagaxi pluton and exhibits strong montmorillonitization, chloritization, and iron-staining alteration, typical for magmatic–hydrothermal controlled mineralization. In contrast, the Y2 target is strictly controlled by the Anqi Fault and its subsidiary faults, primarily characterized by linear chloritization and iron-staining anomalies indicative of structure–hydrothermal mineralization. Field verification confirms the significant metallogenic potential of both Y1 and Y2, demonstrating the effectiveness of integrating multi-source remote sensing and machine learning for predicting orogenic gold systems. This approach not only deepens the understanding of the diverse gold mineralization processes in the Western Junggar but also provides a transferable methodology and case study for improving regional mineral exploration accuracy. Full article

Recent discoveries of fluorite–barite deposits in the Donghai–Linshu area in northern Jiangsu Province, China, underscore the region’s mineral potential, yet detailed geological investigations remain limited. In this study, we examined monzonite and quartz monzonite from drill cores in the Jiashan mining area using petrography, U–Pb zircon dating, zircon trace element geochemistry, whole-rock geochemistry, and zircon Lu–Hf isotopes. Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) zircon U–Pb analyses were conducted to constrain the crystallization ages of the monzonite (127.06 ± 0.54 Ma and 126.83 ± 0.75 Ma) and quartz monzonite (127.2 ± 0.5 Ma and 128.59 ± 0.62 Ma) to the Early Cretaceous, marking a significant magmatic event. Many of the zircons contain inherited Neoproterozoic cores (718–760 Ma and 800–860 Ma), indicating the assimilation of deep crustal materials of this age. The monzonite is metaluminous, with moderate SiO₂ (61.61–62.41 wt.%), high alkalis (Na₂O + K₂O = 7.48–7.92 wt.%), and A/CNK = 0.72–0.91. The quartz monzonite has higher SiO₂ (66.26–68.18 wt.%) and alkalis (8.32–9.33 wt.%). Both rock types exhibit similar trace and rare earth element patterns: enrichment in large-ion lithophile and light rare earth elements, depletions in Nb, Ta, and Ti, no significant Zr-Hf depletion, and weak negative Eu anomalies (δEu ≈ 0.84–1.00). Their low Zr + Nb + Ce + Y contents, Ga/Al ratios, and TFeO/MgO ratios indicate that they have an I-type granite affinity. The Early Cretaceous zircons have highly negative ε_Hf(t) values (−33.7 to −23.5) and ancient two-stage model ages (2622–3247 Ma), which are consistent with derivation from Archean crust. The inherited Neoproterozoic zircons have younger Paleo–Mesoproterozoic T_DM2 ages. The evidence suggests that both intrusions were mainly generated by partial melting of ancient Archean basement, with minor mantle input. The magma generation was likely triggered by crustal anatexis induced by the underplating of mantle-derived magmas in an extensional tectonic regime, coeval with Early Cretaceous magmatism in the Sulu orogen. Full article