Search Results (225)

The Damiao titanomagnetite deposit on the northern margin of the North China Craton is a typical Fe-Ti-P polymetallic ore with significant deep resource potential. However, the mineralogical factors controlling its beneficiation remain poorly quantified. This study integrates multi-element analysis, chemical phase analysis, XRD, EPMA, and MLA to systematically characterize the ore’s chemistry, mineralogy, element deportment, grain size, dissemination, and liberation. Results show that Fe (25.81% TFe), Ti (6.50% TiO₂), and P (0.95% P₂O₅) are the main valuables. Fe is mainly in magnetite (59.53%), Ti in ilmenite (48.90%) and rutile (33.89%), and P almost entirely in fluorapatite. Magnetite, ilmenite, apatite, and pyrite are coarse-grained and achieve >80% free + rich intergrowths at 60% passing −0.074 mm, while rutile is fine and poorly liberated, representing the key titanium bottleneck. Silicate-bound iron (28.07% of Fe) causes irreversible loss; Ca-gangue (>20%) and chlorite slimes interfere with flotation. A staged flowsheet—primary grinding, magnetic separation, regrinding of rough concentrate, desulfurization, and sequential flotation—is proposed. This work provides a mineralogical basis for process optimization and offers references for similar deposits. Full article

The NE- to E-trending ductile shear zones are well-exposed in the Wulashan–Daqingshan Complex of the Khondalite Belt, an Orosirian collisional orogen in the northwestern North China Craton. However, the timing of the shear zone activity remains ambiguous. In this study, we performed field-based structural observations and apatite and zircon U–Pb geochronology on these shear zones. The results show that the pre- and post-kinematic intrusions yielded magmatic zircon U–Pb ages of 1967 ± 24 Ma and 1812 ± 18 Ma, interpreted to broadly provide the maximum and minimum age constraints for shearing. Meanwhile, eight samples of mylonites gave a range of apatite U–Pb ages between 1878 ± 34 Ma and 1798 ± 29 Ma, considered to record the timing of shear deformation. Moreover, a similar metamorphic zircon U–Pb age of 1876 ± 38 Ma was also obtained from another mylonite. Combined with available data, we summarized that orogen-parallel ductile shear zones in the Helanshan, Qianlishan, Wulashan–Daqingshan and Jining Complexes of the Khondalite Belt have comparable deformation ages of 1904–1823 Ma, 1902–1801 Ma, 1906–1798 Ma and ~1866 Ma, respectively. These late Orosirian (1.90–1.80 Ga) shear zones were inferred to result from the prolonged orogenic processes of the Khondalite Belt, in response to the collision between the Yinshan and Ordos Blocks. Full article

The Ordos Basin and the adjacent Shanxi region in northern China host multiple energy resources. However, the exhumation history of this region (especially the Cenozoic exhumation history) remains poorly constrained despite its importance for understanding basin evolution and multi-energy resource accumulation within the North China Craton (NCC). This study presents new apatite fission-track (AFT) data and thermal-history models from the eastern Ordos Basin and integrates them with previously published low-temperature thermochronological datasets to reconstruct the regional tectono-thermal evolution and evaluate its implications for mineral and hydrocarbon systems. The new AFT ages range from 39.5 to 24.8 Ma and are concentrated in the Late Eocene-Oligocene, recording two rapid cooling episodes at 39.5–32.7 Ma and 26.6–24.8 Ma. Together with regional thermochronological data, these results define five major tectono-thermal episodes since the Late Ordovician and reveal pronounced spatial variations in exhumation. This pattern indicates that Cenozoic deformation became increasingly localized along inherited basin-margin fault systems while the interior of the Ordos Basin remained comparatively stable. The reconstructed tectono-thermal history demonstrates that Late Jurassic-Early Cretaceous tectono-thermal reactivation coincided with peak hydrocarbon generation and accumulation, whereas Cenozoic uplift and fault reactivation primarily influenced hydrocarbon preservation and coalbed methane enrichment through differential exhumation and structural reorganization. These results refine the Cenozoic exhumation history of the eastern Ordos Basin and establish a regional tectono-thermal framework for understanding the coupled evolution of basin development and the accumulation and preservation of multi-energy resources. Full article

Anthropogenic CO₂ emissions have perturbed the global carbon cycle and increased atmospheric carbon concentrations to critical levels, making carbon capture and storage (CCS) a key strategy for mitigating climate warming. Natural carbon sequestration has operated continuously in marine environments throughout Earth history. Here, we investigate the growth mechanisms and carbon-sink significance of calcite concretions in the Mesoproterozoic Xiamaling Formation from the Zhaojiashan section and the Zhenzhuquan section in the North China Craton, using petrographic, elemental geochemical and C-O-Re-Os isotopic evidence. The presence of erosional surfaces and local truncation of host-rock laminae suggests that these concretions formed synsedimentarily or during early diagenesis near the sediment-water interface. The δ¹³C values (−5.05‰ to 1.54‰) of samples, together with δ¹⁸O-δ¹³C relationships, indicate a marine carbonate affinity and suggest that dissolved inorganic carbon was the dominant carbon source. In addition, the concretions display initial ¹⁸⁷Os/¹⁸⁸Os ratios as low as 0.136, close to the mantle Os end-member, implying a contribution from mantle-derived material during concretion formation. The middle rare earth element and yttrium (MREYs)-enriched patterns and slight positive Ce anomalies further indicate that concretion growth occurred mainly within the Mn- and Fe-reduction zones. We estimate that the calcite-concretion-bearing interval of the Xiamaling Formation sequestered 70.24 Gt C, equivalent to 257.56 Gt CO₂, serving as an archive of marine carbon burial in the Mesoproterozoic ocean. Microbially mediated carbonate precipitation may represent an effective carbon immobilization mechanism in marine sediments and has potential implications for the development of subseafloor carbon storage strategies, especially where biocatalysts and/or brine could accelerate seawater CO₂ mineral trapping to industrially relevant rates. Full article

The North China Craton hosts abundant skarn iron resources, yet the regional large-scale mineralization mechanism remains incompletely understood. The Litun deposit is a newly discovered skarn iron deposit in the North China Craton. Integrated field geological investigations, petrographic observations, fluid inclusion microthermometry and stable isotope geochemistry are applied to constrain evaporite contributions to metallogenic processes. Four mineralization stages are identified: skarn, oxide, sulfide, and carbonate. Early skarn-stage fluids are iron-rich magmatic hydrothermal fluids with high temperatures (498 to >550 °C), high salinities (18.6 to 59.4 wt% NaCl eqv.), and magmatic δ¹⁸O values of 8.3 to 10.8‰. Subsequent oxide to late carbonate stages record continuous infiltration of meteoric water, supported by H–O isotopic trends of rising meteoric water proportions. Pyrite from the magnetite ores has δ³⁴S_V-CDT values between 12.0 and 15.0‰, significantly higher than those of pyrite in the Litun diorite (−0.8 to 1.1‰), indicating the contributions of sulfur from evaporites (δ³⁴S_V-CDT 26.9 to 28.6‰) in the mineralization process. Moreover, vein pyrite formed in later stages displays even higher δ³⁴S values (17.3 to 20.9‰), demonstrating progressive enrichment of evaporite-derived sulfur as hydrothermal activity evolves. Synchronous rises in meteoric water fraction and evaporite sulfur proportion indicate evaporites are delivered into the ore-forming system via meteoric water mixing. The mixing of meteoric water containing dissolved evaporites and iron-rich magmatic-hydrothermal fluids may be the major mechanism of magnetite precipitation in the Litun deposit. Full article

A catastrophic Ms7.8 earthquake occurred in Tangshan in 1976 at a focal depth of approximately 12 km, resulting in severe casualties and substantial economic losses. Given its unique tectonic setting, the seismogenic structure and dynamic genesis of the Tangshan earthquake have long remained a key research topic in seismotectonic studies. To better characterize the tectonic framework, seismogenic mechanisms, and deep–shallow dynamical coupling within the Tangshan seismic zone, we employ multi-scale wavelet decomposition on high-resolution residual gravity anomalies to isolate crustal structure signals across different depth ranges. Integrating these structural signatures with the spatial distribution of seismicity yields a comprehensive framework for interpreting the regional tectonic evolution. The Tangshan seismic zone is positioned within the intricate structural architecture of the Tangshan rhombic fault block, a system embedded within the broader context of the North China Craton (NCC) destruction. Seismicity displays a distinct preferred orientation, with events concentrated along block-bounding faults and gravity anomaly gradient zones. With increasing wavelet decomposition levels, the gravity anomalies exhibit a systematic transition from spatially dispersed patterns associated with shallow structures to more concentrated features reflecting deeper geological domains. Shallow anomalies from the first to third decomposition orders, which are primarily controlled by Quaternary sedimentary layers, show a fragmented distribution that corresponds well with the development of local flower structures and the occurrence of diffuse shallow seismicity. The fourth- to seventh-order anomalies clearly delineate the rhombic block and its bounding peripheral faults, highlighting the structural intersections that hosted the Tangshan mainshock and its associated aftershock sequence. In contrast, the eighth- to tenth-order deep-seated anomalies corresponding to deeper structural levels exhibit pronounced coalescence, effectively imaging mantle upwelling and large-scale density heterogeneities within the lithospheric mantle. These concentrated gravity highs are closely coupled with mantle thermal activity, whose upward ascent induces thermal weakening of the lower crust and facilitates progressive stress transfer toward shallower crustal levels. Concurrently, frictional locking of shallow high-angle faults promotes intense stress accumulation within the rigid basement. The interplay between deep-seated dynamic concentration and shallow structural confinement ultimately triggers the catastrophic coseismic rupture responsible for the Tangshan earthquake. By delineating the structural transition from deep-seated aggregation centers to shallow dispersed fracture zones, this study establishes a robust framework for assessing seismogenic environments and regional seismic hazard potential across the progressively destroyed NCC. Full article

Crystal size distributions (CSDs) of metamorphic minerals provide quantitative constraints on nucleation-growth kinetics and metamorphic thermal regimes. Early interpretations linked CSD shape to type of metamorphism, associating near-linear CSDs with rapid-contact metamorphism and bell-shaped CSDs with prolonged regional metamorphism. Subsequent works showed that diffusion-controlled nucleation and growth can also produce bell-shaped CSDs without annealing, leaving unresolved how contrasting thermal regimes are expressed in interface-controlled systems. The Fangshan tectonic dome at the northern margin of the North China Craton comprises multiple metamorphic zones, recording Mesozoic contact metamorphism of Fangshan plutons and a concealed pluton in the Nanjiao area. We employed high-resolution X-ray micro-computed tomography (micro-CT) to quantify the 3D crystal size distributions of garnets of contact metamorphic samples from the Nanjiao area and the Fangshan contact aureole. Integrated 3D CSDs with spatial statistics, reconstructed nucleation curves, garnet compositional zoning, and thermodynamic phase equilibrium modeling were used to decipher crystallization kinetics in interface-controlled systems. Nucleation and growth of garnets from the Nanjiao area, and one sample from the Fangshan contact aureole, which is separated from the main heat source by an earlier intruded magma body, are interface-controlled, and display bell-shaped CSDs together with sigmoidal nucleation curves that record a progressive increase followed by a gradual decline in nucleation rate. Phase equilibrium modeling and garnet compositional profiles of a sample from Nanjiao demonstrate that the late-stage deceleration of nucleation in interface-controlled systems is fundamentally driven by whole-rock constituents’ exhaustion rather than the geometric impingement of diffusion halos. In contrast, another contact sample, which is collected near the main heat source, is diffusion-controlled, and displays a steep J-shaped nucleation curve with a delayed, broad peak nucleation rate followed by rapid late-stage suppression. The 3D textures of these metamorphic rocks suggest that contact and regional thermal regime alone do not determine garnet population characteristics; bell-shaped CSDs can be produced in contact metamorphic environments. We propose that heating rate is the primary control on the resulting crystal size distributions. Full article

The Heilongtai–Maogudui (HM) mafic intrusions are exposed in the southern margin of the North China Craton (SNCC), which are contemporaneous with a variety of strategic metal/non-metal minerals (niobium, uranium, and high-purity quartz) and magmatic hydrothermal REE deposits. New geochronology and geochemistry of these intrusions are examined and interpreted to decipher their petrogenesis and tectonic settings. Zircon LA–ICP–MS data formed a concordant cluster, yielding a mean ²⁰⁶Pb/²³⁸U age of 397.5 ± 3.5 Ma, which is interpreted as an Early Devonian crystallization age. The HM mafic intrusions have similar whole-rock geochemical compositions, containing 48.94–51.51 wt% SiO₂, 1.26–1.61 wt% TiO₂, 5.96–7.13 wt% MgO, and 11.00–12.48 wt% FeO_t. The total alkali contents range from 1.61 wt% to 3.53 wt%, with Mg^# values of 47.23–52.30. The petrographic and geochemical results suggest the fractional crystallization of mainly olivine, clinopyroxene, and minor Fe–Ti oxide in the mafic intrusions. Being of tholeiitic composition, these mafic rocks display relatively flat rare earth element (REE) and trace element patterns, which are similar to those of the normal mid-ocean ridge basalt (N–MORB) and the enriched mid-ocean ridge basalt (E–MORB). The HM mafic intrusions are proposed to originate in the continental extensional environment through 5–10% partial melting of the depleted spinel asthenosphere mantle source. This is attributed to the gravitational delamination of the lithospheric mantle and the upwelling of the hot asthenosphere, marking the end of the Paleozoic Proto–Tethyan orogenic cycle. The Paleozoic strategic mineral deposits are proposed to have formed under this specific tectonic regime. 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 Shizui Cu–Pb–Zn deposit is located in central Jilin Province. It sits at the tectonic junction between the eastern Xing’an–Mongolia Orogenic Belt (XMOB) and the northeastern North China Craton (NCC). This is the first discovered Paleozoic Cu-polymetallic deposit in the region. Our study combines detailed geological investigation with systematic fluid inclusion analysis. We analyzed samples from four distinct paragenetic stages. Analytical methods include microthermometry, laser Raman spectroscopy, and hydrogen-oxygen isotope analysis. These data constrain the source, evolution, and precipitation mechanisms of the ore-forming fluids. The results delineate a clear evolutionary path: the ore-forming fluid originated as a high-temperature (346–437 °C), high-salinity (up to 51.68 wt.% NaCl equiv.) NaCl–H₂O–CO₂ system during the early quartz-sulfide stage (Stage I, Quartz ± Arsenopyrite ± Pyrite Stage), as evidenced by the coeval presence of high-salinity S-type and CO₂-rich C-type inclusions, indicating fluid immiscibility. The fluid then evolved into a boiling, medium temperature to high temperature (262–355 °C), high-salinity NaCl–H₂O system during the later part of early quartz-sulfide stage (Stage II, Quartz-Cu Polymetallic Sulfide Stage), a transition marked by the common coexistence of liquid-rich (L-type) and vapor-rich (V-type) inclusions with similar homogenization temperatures. This phase separation (boiling) served as the primary trigger for the massive deposition of chalcopyrite, arsenopyrite, and pyrite. Subsequently, the system cooled and diluted, transforming into a medium- to low-temperature (182–275 °C), low-salinity, partially homogeneous NaCl–H₂O system in the late quartz-sulfide stage (Stage III, Quartz-Pb-Zn Polymetallic Sulfide Stage). Finally, in the quartz-carbonate stage (Stage IV, Quartz-Carbonate Stage), the fluid temperature further decreased, resulting in a low-temperature (128–211 °C), low-salinity, homogeneous NaCl–H₂O system. Hydrogen-oxygen isotope data show that the calculated δ¹⁸O_H2O values decreased from +6.6‰ to +6.7‰ in Stage I to +3.4‰ to +3.9‰ in Stage II, and further to −0.4‰ in Stage III, while the δD values shifted from −91.6‰ to −90.6‰, to −94.4‰ to −94.2‰, and finally to −95.7‰. This trend indicates that the initial magmatic fluid progressively mixed with meteoric water. The geological characteristics, spatial association with Hercynian biotite monzogranite, developed skarn alteration, and the documented fluid evolution trajectory collectively affirm that the Shizui deposit is a typical skarn-type system. The deposit shares significant similarities in mineralization conditions, age, and tectonic setting with the skarn-type Tianbaoshan Pb–Zn–Cu–Mo deposits in the western segment of the XarMoron–Changchun Metallogenic Belt (XCMB). This correlation strongly suggests that the Paleozoic XCMB extends eastward and holds considerable potential for the discovery of late Paleozoic skarn-type Cu-polymetallic deposits in its eastern part. Full article

The Niutougou ore area (~31 t Au) is located in the Xiong’ershan district at the southern margin of the North China Craton (NCC). From north to south, the Niutougou ore area is divided into three main parts, corresponding to the gold deposits in the Songligou altered rocks, the J25-J26 breccia, the Vein VII lode gold deposit, and the Shangzhuang altered rocks. The timing of gold mineralization and the formation age of the J26 breccia pipe have not been well constrained in this ore area. Hydrothermal xenotime and apatite are closely related to gold mineralization. The in situ xenotime U–Pb ages of the J26 breccia pipe and Vein VII show U–Pb lower intercept ages of 151.2 ± 2.0 Ma and 155.9 ± 1.6 Ma, respectively. The in situ U–Pb age of the Shangzhuang apatite shows a U–Pb lower intercept ages of 153.4 ± 2.6 Ma. The U–Pb concordia ages and weighted mean ages of the cement zircons from the J26 breccia pipe are 155.8 ± 0.4 Ma, and 155.9 ± 0.8 Ma, respectively, determined via sensitive high-resolution ion microprobe (SHRIMP) analysis. The molybdenite veins in the J26 breccia pipe cut the cement and different types of breccia and have a Re–Os isochron age of 155.9 ± 2.9 Ma and weighted mean age of 155.9 ± 1.1 Ma. Thus, the formation age of the breccia pipe is Late Jurassic. The subduction of the paleo-Pacific Plate beneath the NCC and the back-arc extensional setting in the Late Jurassic might have caused gold mineralization in the southern margin of the NCC. Full article

Porphyry-type deposits are characterized by well-developed alteration zoning, among which potassic alteration is closely associated with mineralization and represents a key target for prospecting and exploration. The Dengshang molybdenum deposit is a porphyry-type deposit within the Yanliao molybdenum metallogenic belt. Characterized by deep burial and unclear alteration zoning, it presents challenges for prospecting and exploration. This study integrates field surveys, petrographic analysis, and terahertz time-domain spectroscopy (THz-TDS) to characterize the altered wall rocks and molybdenite ores, aiming to support deep prospecting. The main findings reveal a clear spatial gradient from potassic to propylitic alteration zones within and around the rhyolite porphyry intrusion. THz-TDS reveals that the THz spectral characteristics of potassic-altered wall rocks are closely related to the structure of minerals and the intensity of hydrothermal alteration. Propylitically altered wall rocks exhibit distinctive spectral signatures in the terahertz band. For molybdenite ores, the molybdenite content shows a negative correlation with THz amplitude and a positive correlation with both the absorption coefficient and refractive index. This study proposes that the lower refractive index and absorption coefficient of potassic wall rocks, coupled with the higher values in ores, reflect the spatial position of the ore body. Additionally, the characteristic THz spectral curve of propylitically altered rocks can aid in delineating ore body boundaries. These findings hold practical guiding significance for prospecting and exploration. Full article

The Paleoproterozoic represents a pivotal but poorly constrained interval in the tidal evolution of the Earth–Moon system. Quantifying Earth–Moon orbital parameters over this interval is fundamental for predicting the long-term dynamical evolution of the Earth–Moon system, yet direct geological evidence remains scarce. In this study, we conducted cyclostratigraphic analyses of the middle and upper members of the Dagushi Formation on the southern margin of the North China Craton, using high-resolution magnetic susceptibility (MS) and phosphorus (P) data as paleoclimate proxies. By employing two independent astrochronologic approaches—the main obliquity estimation method ($k+s_3$) and Bayesian inversion (TimeOptMCMC)—we reconstructed key parameters of the Earth–Moon system, including the precession constant k, Earth–Moon distance, and length of day (LOD). The $k+s_3$ approach yields $k=98.12\pm 1.07$ arcsec/yr, from which the Earth–Moon distance is derived as 329,732 (+888/−877) km, with a LOD of $17.69\pm 0.08$ h. In contrast, the TimeOptMCMC method produces $k=95.20\pm 1.68$ arcsec/yr, implying an Earth–Moon distance of 331,292 (+1446/−1418) km, with a LOD of $17.91\pm 0.13$ h. The MS and P indicators exhibit remarkable symmetry and phase synchronicity between their curves in both depth and time domains, serving as a robust indicator of stable sedimentation and primary depositional signals. These results provide direct geological constraints on Earth–Moon system parameters at ∼1787 Ma, contributing to a refined understanding of its tidal evolution during the Paleoproterozoic. Full article

The Dongwujiiazi deposit is a structurally controlled orogenic gold deposit situated in the eastern part of the Chifeng–Chaoyang gold belt along the northern boundary of the North China Craton. This study establishes a comprehensive metallogenic model for the Dongwujiiazi gold deposit by integrating whole-rock geochemistry (major and trace elements), in situ trace elements and REEs in zircon, multi-isotope systems (H, O, S, Pb), and precise zircon U–Pb geochronology. Five types of intrusive and associated rocks are identified within the main biotite-pyroxene gneiss host of the Dongwujiiazi gold deposit: mylonitized granitic pegmatite, mylonitized porphyritic monzogranite, propylitized fine-grained quartz monzodiorite, quartz monzonite, and porphyritic dolerite. The gold-bearing polymetallic sulfide ores are composed of pyrite, chalcopyrite, sphalerite, galena, digenite, and native gold. Zircon grains in the Dongwujiiazi gold ore (2502 ± 15 to 2539 ± 18 Ma) are inherited from surrounding Neoarchean gneiss, recording older crustal sources rather than forming contemporaneously with the gold mineralization. H–O isotopes indicate that the ore-forming fluids were mixed in origin, involving both magmatic and metamorphic components. S and Pb isotopes suggest that the mineralizing sulfur was mainly derived from a magmatic source, while lead originated predominantly from lower crustal materials associated with the surrounding high-grade metamorphic rocks. In this study, we present a new metallogenic model for the Dongwujiiazi gold deposit, in which slab-derived and lower-crustal metamorphic fluids interacted with ascending magmas, resulting in fluid mixing and gold precipitation within structurally controlled zones of gneissic host rocks. Combined geochemical and isotopic evidence (H–O, S, Pb) indicates contributions from both magmatic and metamorphic sources, supporting formation as an intracontinental orogenic gold system in an active continental margin. Full article

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. Full article