The Archean Eon is a crucial stage in the early Earth’s evolution, and its geological processes and geodynamic models are significantly different from those of the Phanerozoic Eon. Multiple clues from structural geology, petrology, geochemistry, and numerical modelling support the prevalence of microplate tectonics in the Archean and suggest that the subduction, accretion, and collision amalgamation of microplates may have dominated the formation and evolution of the early continental crust. This review delves into the theoretical frameworks, methodologies, and models used for microplate reconstruction during the Archean Eon. By combining isotope mapping, regional geological comparison, and various geophysical probing methods, we can effectively exclude the strong interference of later tectono-thermal events and accurately identify Archean microplates in the early Precambrian crystalline basement. The Archean microplate tectonics are essentially an intense and complicated crust-mantle interaction, which controls the migration and enrichment of elements and thereby influences the formation and distribution of metallic mineral resources. Furthermore, the initiation of Archean microplate tectonics completely reshaped early Earth’s sea-land distribution, shifting the planet from a water-dominated to a more continent-rich world, driving environmental transformation through the coupling of weathering and biological processes. Therefore, Archean microplate tectonics has important resource and environmental effects, which provide new insights for understanding the formation of a habitable Earth.

A wealth of geological and geochemical evidence indicates that plate tectonics was initiated in the Archean, though its style differing from that in the Phanerozoic, largely due to higher temperatures of convective mantle. Understanding the specific characteristics for the operation of ancient plate tectonics is critical for deciphering the formation and evolution of continental crust on early Earth, as well as the progressive development of Earth’s habitability. Through an in-depth analysis of geology and geochemistry for two events of late Archean crustal growth in the North China Craton, this study suggests that Archean plate tectonics would likely undergo the gradual evolution from immature to mature phases. The North China Craton experienced two major episodes of crustal growth at ∼2.9–2.7 and ∼2.6–2.5 Ga, respectively, represented by peaks in isotopic model ages of Archean felsic gneisses and widespread mafic rocks in greenstone belts. Although the preserved mafic rocks in greenstone belts generally exhibit arc-like trace element signatures, the early mafic crust formed at ∼2.9–2.7 Ga is limited in volume, with most of it having been reworked within several hundred million years. Tonalite-trondhjemite-granodiorite (TTG), produced by partial melting of such mafic crust, show zircon Hf-O isotope compositions indicative of sources consisting of seawater-hydrothermally altered oceanic crustal rocks with varying ages, suggesting that the early mafic crust was likely dominated by oceanic basalts. The medium- to low-pressure signatures of TTG rocks further imply that the oceanic crust was not subducted deeply to mantle depths, but instead was accreted to the margin of proto-continental nuclei due to aborted subduction. In contrast, the ∼2.6–2.5 Ga crustal growth event preserved a greater volume of mafic rocks. For these mafic rocks, the enrichment of incompatible elements correlates with water contents estimated from whole-rock major elements, indicating that their arc-like trace element features were associated with fluid metasomatism of the source region. Integrated with regional geological evidence from ∼2.5 Ga, such as ophiolites containing ultrahigh-pressure mineral inclusions and eclogite-facies remnants of oceanic crust, these observations suggest that modern-style plate subduction was likely in operation by the end of the Late Archean. Therefore, the modern plate tectonics regime did not emerge abruptly, but underwent a gradual evolution controlled by the thermal state of plate margins. It is this evolving tectonic regime that drove the significant crustal growth during the Archean. The two distinct episodes of crustal growth ultimately led to the formation of the North China Craton.

The North China Craton (NCC), confined by a series of late Paleoproterozoic-Neoproterozoic extensional basins, is likely a key piece in welding the supercontinent Columbia. The debate regarding the connection between the northern NCC and either the North Australia Craton or the Siberia Craton is essential for understanding the assemblage and break-up of Columbia. The northern marginal rift system (NMRS) of the NCC is an ideal region in which imprints related to neighboring cratons could be preserved. However, the absence of a well-calibrated chronologic framework obstructs subregional attribution and regional correlation and obscures the tectothermal reconstruction of the Proterozoic NMRS, although the zircon U-Pb ages of the volcanic interbeds and crosscutting dykes were sporadically obtained from the Bayan Obo, Zha'ertai, Huade, Shi'nagan and Langshan groups. This study presents two SHRIMP U-Pb ages constraining the Sailinhudong Group (SG) in Darhan-Muminggan Joint Banner to the early Mesoproterozoic (probably the early Calymmian), including one zircon U-Pb age of ca. 1.58 Ga from a volcanic interbed and the other baddeleyite Pb-Pb age of ca. 1.31 Ga from a crosscutting gabbro-diorite dyke. Zircon Hf isotopic compositions of the ca. 1.58 Ga tuff layer in the volcanic-seismic succession from the lower SG are all depleted, similar to those of the ca. 1.58 Ga tuffite layer overlying the seismic succession in the third member of the Gaoyuzhuang Formation in the Yanliao Rift. In conjunction with previous studies, we propose an external origin for the tuff layers and associating seismic successions. A ca. 1.58 Ga catastrophic eruption is inferred to have transmitted substantial tephra and emanated considerable energy to the northern NCC. The ca. 1.58 Ga catastrophic event is considered an anchoring point for attributing and correlating the Calymmian successions through the northern NCC. According to the latest lithostratigraphic and chronostratigraphic advances, the late Paleoproterozoic-Neoproterozoic successions outcropping in the NMRS are further subdivided into the Statherian (the Zha'ertai Group and lower parts of the Bayan Obo and Huade groups), Calymmian (the Sailinhudong, Shi'nagan and middle parts of the Bayan Obo and Huade groups) and Tonian (the northern Langshan Group).

Extensive studies of Aptian oceanic anoxic events and carbon cycle perturbations have significantly advanced our understanding of marine responses to global climate change. However, further exploration of possible volcanism-climate-environment linkages is hindered by the scarcity of continuous, well-documented terrestrial records. In an attempt to address this gap, the Yanshan Scientific Drilling Project extracted a 1497.5 m core from the shale-dominated, lacustrine, Jiufotang Formation in the Kazuo Basin of Northeast China. High-precision U-Pb geochronology of two interlayered tuffs yielded depositional ages of 121.05 +/- 0.32 Ma and 117.359 +/- 0.031 Ma, and a Bayesian age-depth model for the lower half of the formation. An astrochronological model based on delta 13Corg and major element chemostratigraphy has suggested a duration of 9.03-9.14 Ma for the entire core, from 121.05 to 121.30 to 111.91-112.20 Ma. A 75.2 m core interval with unequivocal correlation to the oceanic anoxic event (OAE) 1a was identified by carbon isotope stratigraphy, which has a calibrated onset at 120.2 Ma and a total duration of ca. 450 kyr. Our results highlight the potential of lacustrine strata in recording at highresolution the marine-correlated carbon cycle changes and in deciphering the drivers and mechanisms of climate change across the marine and terrestrial realms.

Frequent geological hazards such as landslides and rockfalls, intensified by human activities and extreme rainfall, highlight the urgent need for rapid, accurate, and interpretable susceptibility assessment. However, existing methods often struggle with insufficient characterization of spatial heterogeneity, fragmented spatial structures, and limited mechanistic interpretability. To overcome these challenges, this study proposes an intelligent landslide susceptibility assessment framework based on the Swin-UNet architecture, which combines the window-based self-attention mechanism of the Swin Transformer with the encoder–decoder structure of U-Net. Eleven conditioning factors derived from remote sensing data were used to characterize the influencing conditions. Comprehensive experiments conducted in Changbai County, Jilin Province, China, demonstrate that the proposed Swin-UNet framework outperforms traditional models, including the information value method and the standard U-Net. It achieves a maximum overall accuracy of 99.87% and consistently yields higher AUROC, AUPRC, F1-score, and IoU metrics. The generated susceptibility maps exhibit enhanced spatial continuity, improved geomorphological coherence, and greater interpretability of contributing factors. These results confirm the robustness and generalizability of the proposed framework and highlight its potential as a powerful and interpretable tool for large-scale geological hazard assessment, providing a solid technical foundation for refined disaster prevention and mitigation strategies.

Recent studies have highlighted Paleoproterozoic magmatic and metamorphic events within the Alxa block. Although these geological records are generally believed to be associated with Paleoproterozoic orogenic events, the nature and location of the potential orogenic belt remains poorly understood. In this paper, we systematically investigate U-Pb-Lu-Hf isotope analyses of detrital zircons, alongside whole-rock major and trace element analyses from a suite of Paleoproterozoic meta-supracrustal rocks in the Beidashan complex, to provide new insights into this enigmatic orogenic event. The formation age of the upper sequence of the meta-supracrustal rock suite is constrained to 1.89 similar to 1.83 Ga, with detrital zircons exhibiting a unimodal distribution centered at similar to 1.96 Ga and Hf model age peaks at similar to 2.4 Ga and 2.6 similar to 2.7 Ga. In contrast, the deposition age of the lower sequence is constrained to 2.08 similar to 2.05 Ga, with detrital zircons show age peaks at ca. 2.20 Ga, 2.30 Ga and 2.41 Ga, and a Hf model age peak at similar to 2.95 Ga. Geochemical analyses reveal that amphibolites from the upper sequence are enriched in light rare earth elements (LREE) and show negative Nb and Ta anomalies. Conversely, amphibolites from the lower sequence display relatively low REE differentiation and are depleted in high field strength elements (HFSE). Both sequences exhibit Nb-Ta troughs, characteristic of typical continental arc basalts and andesites. The amphibolites from the upper sequence are more enriched in LREE, which likely indicates their formation in a late-orogenic environment. The detrital zircons from the Beidashan complex exhibit age distributions and Lu-Hf isotope compositions that align with the Archean-Paleoproterozoic magmatic rocks exposed in the Alxa block. This alignment suggests that the Beidashan, Longshoushan and Bayanwulashan regions to the south of the Alxa block likely served as the source area for the lower sequence, while the Diebusige region to the north may be the provenance for the upper sequence. This provenance shift around similar to 1.9 Ga likely reflects the uplift of an accretionary orogen north to the research region, which not only introduced new juvenile material into the sedimentary record but also stopped the original material supply from the south. Therefore, we propose that the Alxa block experienced an orogenic event north to the Beidashan complex during 2.1 to 1.8 Ga, potentially related to the subduction and collision between an unknown continent and the Alxa block along its northern margin, contributing to the formation of the Columbia supercontinent.

The newly discovered Bayanbaolege Ag-Pb-Zn deposit is located in the Southern Great Hinggan Range metal-logenic belt, northeastern China, with 1440 t Ag, 380000 t Zn, 50000 t Pb, and a beneficial component of Cd (806 t Cd) and Ga (211 t Ga). The orebodies of this deposit occur as veins and are hosted mainly by a contact zone between the Permian silty slate and the granite intrusion, and have a closely spatio-temporal relationship with the early Cretaceous granodiorite porphyry intrusion. The mineralization process of the Bayanbaolege deposit can be divided into three mineralization stages including arsenopyrite-pyrite-quartz stage (stage I), pyrite-pyrrhotite-chalcopyrite stage (stage II) and galena-sphalerite-argentite-pyrite-calcite stage (stage III). LA-ICP-MS trace element mapping and spot analyses were conducted on the sphalerite and pyrite in stage III at the Bayanbaolege deposit. LA-ICP-MS trace element mapping and spot analyses were conducted on the stage III sphalerite and pyrite selected from the Bayanbaolege deposit in order to identify the occurrence form and distribution characteristics of critical metal elements, constrain the possible controls on the variation of trace elements, reveal the physi-cochemical condition of mineralization and provide new insights into the ore genesis. The results show that Ga, Ge, In, Cd, Mn, Cu, Ag and Co concentrations in sphalerite, and pyrite is the preferential host for Ge, As and Ni. The occurrence of Ga, Ge, In and Cd in sphalerite are mainly deposited in form of isomorphism. Physicochemical condition studies suggest that sphalerite precipitated from a medium-temperature hydrothermal system with the range from 190 degrees C to 291 degrees C (average at 230 degrees C) and accompanied with the intermediate fS2. Trace element concentrations of sphalerite are different from that of the MVT, VMS, SEDEX and skarn deposits. The results of this study, combined with the previous geological and physicochemical evidence, indicate that the Bayanbaolege Ag-Pb-Zn deposit deposit is an intrusion-related mesothermal hydrothermal vein-type deposit.

When and how plate tectonics started and evolved to the style as we know it today is a fundamental yet highly controversial question. Numerical geodynamic modelling predicts that the transition into plate tectonics in the Archean was episodic with possible alternation between success and failure of subduction. However, direct geological evidence for failed subduction is scarce. While this possibility has been suggested by numerical modelling, it is still lack of geological evidence. Here we present a combined study of zircon U-Pb ages and Hf-O isotopes, as well as whole-rock major and trace elements, for meta-igneous rocks from the Alxa Block in the westmost North China Craton (NCC). Two periods of Late Archean magmatism ca. 2.75 Ga and 2.5 Ga are identified to occur surrounding a pre-3.0 Ga continental nucleus. Geochemical analyses of the ca. 2.75 Ga metamafic and meta-felsic igneous rocks show two different modes of tectonic regime. The felsic rocks resemble typical Archean TTG (tonalite-trondhjemite-granodiorite) in composition, with variable epsilon Hf(t) values from -2.8 to 11.0 and delta 18O values from 4.3 %o to 7.9 %o. Petrogenetic modelling suggests that their magmatic source was the ca. 3.1-2.75 Ga oceanic crust that was hydrothermally altered at different temperatures and then mixed with the older continental crust and partially melted in lower crust in the garnet stability field. This requires tectonic accretion of the oceanic crust to the continental nucleus, signifying an attempted or failed subduction. On the contrary, the meta-mafic rocks exhibit arc-like trace element patterns and calc-alkaline evolution trend, indicating a metasomatic mantle source due to successful subduction of the oceanic slab to subarc depths. Taken together, the present results provide robust constraints on the behavior of oceanic slab at the Archean convergent margin, where successful oceanic subduction would be achieved after several failed attempts. Such failuresuccess processes of oceanic subduction may be applicable to the whole NCC and other cratons elsewhere in the world, reflecting the gradual maturation of plate tectonics in the Archean, consistent with predictions of numerical modelling.

Linkage of fault segments is a critical process during the forma-tion of strike-slip faults, and it influences the generation and dis-tribution of related structures. In this study, we investigate the linkage processes and formation mechanism for the strike-slip faults in the Shunbei area of the Tarim Basin based upon newly acquired three-dimensional seismic data. The seismic interpreta-tions suggest that the northeast-trending SB-1 fault and the approximately north-trending SB-5 fault are strike-slip faults with the development of superimposed flower structures in the cross-section views. In the plan view, segments of these faults show a step-like arrangement. We infer that the main activities of these strike-slip faults took place in the Middle and Late Ordovician. The linkage underwent two phases. The first phase was the linkage of R and P shears along with different segments by forming principal displacement zones. The second phase was the linkage of different segments by forming overstepped zones, culminating in the flower structures. Overall, under the influ-ence of the subduction of the Paleo-Asian and Proto-Tethys oceans and the orogenesis surrounding the Tarim craton, the for-mation of the strike-slip faults in the Shunbei area experienced three stages, including the initial stage in the Cambrian, the highly developed stage in the Middle and Late Ordovician, and the weak activity stage from the Silurian to the early Carbonifer-ous. Through fault linkage, the damaged area of the fault segments was enlarged, with the presence of the overstepped zones and complex internal architectures, which provided efficient pathways for fluid migration.

This paper collates information on the current status of investigations and related handaxes in the Baise Basin over the last 50 years, focusing on the Fengshudao site, through a metrological analysis of handaxes Type,Shape, size, lithology and other attributes) and other areas (other sites in the Baise Basin, the Luonan Basin, the Imjin/Hantan River Basins , the Geum River Basin, the Yeongsan River Basin, the Acheulian handaxes in the western Old World) for comparative analysis and to understand their nature. The Baise handaxe belongs to the pebble industry in southern China. Because its cultural attributes include Acheulean technology, it occupies a pivotal position in the pebble culture of southern China and Asia. From its discovery in the early 1970s to the present, in the past 50 years, relevant investigations and research have achieved scientific research results, which have attracted widespread attention from the international academic community. Therefore, Chinese academic circles have also begun to discuss the ‘Movius line’. At present, there are 41 sites containing handaxes in the Baise Basin, and a total of 499 handaxes have been found. Among them, 11 were excavated from strata, and the rest were collected from the surface. The Fengshudao handaxes were basically made from large flakes and pebbles, with three types of stone: sandstone, quartzite and igneous rock. The sandstone is the most abundant and has the most stable ‘broadness’(B/L) and ‘flatness’(Th/B). According to the results of the metrological analysis, the ‘broadness’ (B/L) and ‘flatness’ (Th/B) indices of the Fengshudao handaxes are relatively high, and the ‘Pointness’ (B1/B2) index is relatively low. A comparison with other sites in the Baise Basin, the Luonan Basin, the Imjin/Hantan River Basins , the Geum River Basin, the Yeongsan River Basin, the Acheulian handaxes in the western Old World Acheulean handaxe shows that the Fengshudao handaxe is broader, thicker and has a more pointed base. In terms of industrial assemblages, handaxes and picks are common forms of assemblage in the Baise Basin, while Cleavers are rare, which is a clear difference from the Acheulian industry of the western Old World.

The southern Great Xing’an Range is located in the eastern Central Asian Orogenic Belt, where voluminous igneous rocks developed during the Late Mesozoic period. The east slope of the southern Great Xing’an Range has been the topic of numerous debates on the level of influence of the Mongol-Okhotsk and the Paleo-Pacific regimes in the Late Mesozoic period. Therefore, this area is a suitable region in which to study the temporal changes in magma sources and tectono-magmatic evolution. In this paper, whole-rock geochemical data, zircon U-Pb geochronology, and zircon Hf isotope studies were carried out on the granitoids in the east slope area of the southern Great Xing’an Range. LA-ICP-MS zircon U-Pb dating revealed the ages of four granitoid samples: 135.0 ± 0.6 Ma, 130.7 ± 1.4 Ma, 130.4 ± 1.0 Ma, and 127.6 ± 0.8 Ma, respectively. The Hf isotope values 176Hf/177Hf = 0.282751–0.283015, εHf (t) = +2.0~+11.5, and T2DM = 583~1442 Ma suggest that the magma was generated by partial melting of Meso- and Neoproterozoic accreted and thickened low crust. The whole-rock geochemical data implied that these granitoids are A-type granite and their formation is closely linked to the subduction of the Paleo-Pacific Ocean plate. These geochemical, isotopic, and geochronological data suggest that the Early Cretaceous magmatism in the east slope area of the southern Great Xing’an Range formed in an extensional back-arc tectonic setting associated with the slab roll-back of the Paleo-Pacific plate subduction.

The West Junggar terrain (WJT), as a crucial part of the Central Asian Orogenic Belt (CAOB), is distributed with numerous igneous rocks, which provide critical information for crustal growth. However, the closure of the Junggar Ocean (JO) and the beginning of the postcollisional tectonic stage of the WJT have been controversial. This study delimited the regional lithologic units based on remote sensing geological mapping and recognized a series of bimodal volcanic rocks (BVR) in Hala’alate Mountain of the WJT. LA-ICP‒MS zircon U‒Pb geochronology and geochemistry were used to discuss the petrogenesis of the BVR and determine the stage of regional tectonic evolution. Geochronological results yield crystallization ages of 302 ± 4 Ma, 298 ± 2 Ma, 304 ± 1 Ma, and 303 Ma± 2 Ma for the basaltic andesite, basalt, and two rhyolitic samples, respectively. Basalts and basaltic andesites are calc-alkaline, and display enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs). Notably, basaltic andesites in this area were once misjudged as sanukitoids owing to their low contents of Mg#, Ni, Cr, and other characteristics that are inconsistent with the typical definition of sanukitoids. The rhyolites are A2-type granitoids with high SiO2 contents and are depleted in Nb, Ta, P, Ti, and Sr, showing enriched LREE patterns with negative Eu anomalies. These features indicate that the magma of the mafic end-member of the BVR is derived from the partial melting of the depleted lithospheric mantle, whereas the felsic end-member magma can be associated with the remelting of the lower crust due to the upwelling and underplating of mafic magma. In combination with previous studies of simultaneous basic dikes and felsic rocks, a postcollisional tectonic stage was proposed for the WTJ during the late Carboniferous, suggesting that the JO was closed.

The Early to Middle Paleozoic tectonic evolution of the Alxa block is still unclear due to the sporadic outcropping of magmatic rocks and widespread coverage by the Mesozoic to Cenozoic sedimentary rocks or sediments, which makes it difficult to contrast and connect the northern margin of the Alxa block with the adjacent tectonic units. We address this key issue using new geochronological and geochemical analyses of the Early to Middle Paleozoic igneous and metamorphic rocks from the Alxa Block and its northern margin. Early Paleozoic plutons outcropping on the northern margin of the Alxa Block show slightly enriched to depleted isotopic compositions and arc-related geochemical characteristics, similar to Bainaimiao arc plutons on the northern margin of the NCC, supporting the western extension of the Bainaimiao arc. In contrast, Early Paleozoic intrusive rocks (458-440 Ma) in the Alxa Block exhibit more enriched isotopic compositions and ancient model ages and were generated in a continental arc setting triggered by southward subduction of the Paleo-Asian Ocean (PAO). The meta-mafic rocks documented ca. 419-415 Ma regional metamorphic events in response to an arc-continent collision event in the northern Alxa Block. Our magmatic and metamorphic data combined with published data reveal that the linear Early to Middle Paleozoic orogenic belt is distributed along the northern margin of the Alxa Block. Similar Early to Middle Paleozoic oceanic subduction and subsequent arc-continent collision evo-lution history support that the Alxa Block was probably a part of the North China Craton during the Early Paleozoic.

The North China Craton (NCC) is distinguished from the majority of Archean cratons in the world by its extensive records of late Neoarchean (2.6–2.5 Ga) mafic magmatism but its rare records of early Neoarchean (ca. 2.8–2.7 Ga) magmatism. Controversial issues have long existed on the tectonic setting of these mafic magmatisms, and it has been enigmatic about the role that the NCC has played in the Archean global tectonics. These issues are addressed by an integrated study of whole-rock major and trace elements as well as zircon Hf and whole-rock Nd isotopes in late Archean basaltic-andesitic rocks from the NCC. There are three episodes of basaltic-andesitic magmatism at ca. 2.88–2.73 Ga, ca. 2.65–2.60 Ga, and ca. 2.56–2.50 Ga, respectively. The first two phases are almost entirely tholeiitic basalts, whereas the last phase is composed of tholeiitic basaltic rocks, tholeiitic andesitic rocks and calc-alkaline rocks. The tholeiitic suites can be subdivided into LREE-depleted and LREE-enriched types in terms of their (La/Sm)N ratios, and the calc-alkaline suites are categorized into conventional andesitic rocks and sanukitoids according to their La/Yb and Sr/Y ratios as well as Sr and Ba concentrations. These rocks show island arc basalts (IAB)-like trace element distribution patterns and high water contents, indicating their formation through subduction zone magmatism. The LREE-depleted basaltic rocks were derived from partial melting of a mantle source that was weakly metasomatized by subduction zone fluids (mainly aqueous solutions), whereas the LREE-enriched basaltic rocks were originated from a mantle source that was significantly metasomatized by subduction zone fluids (including both aqueous solutions and hydrous melts). The tholeiitic andesitic rocks were generated by magma differentiation of the tholeiitic basaltic rocks. The coexistence of LREE-depleted and LREE-enriched tholeiitic rocks resembles the bimodal rock assemblage in backarc basins above modern oceanic subduction zones. The calc-alkaline andesitic rocks and sanukitoids were produced by partial melting of metasomatic domains that were generated by reaction of the mantle wedge peridotite with the hydrous melts, but the mantle source of sanukitoids contain more crustal components with higher melt/peridotite ratios of >0.1, in which the metasomatic agent would contain variable amounts of the low-degree partial melt from dehydrated melting of the subducting basaltic crust. The dominance of tholeiitic basaltic rocks and the lack of >2.8 Ga relict zircons in the basaltic-andesitic rocks indicate that the Archean NCC was characterized by development of a series of oceanic arcs around the continental nuclei. The common occurrence of bimodal basaltic rocks suggests the widespread development of backarc basins in the Neoarchean NCC with respect to the Archean plate tectonics. From the early to late Neoarchean, the basaltic-andesitic rocks became more enriched in alkali contents, higher in K2O/Na2O ratios, and more enriched in Nd and Hf isotope compositions. This indicates that more and more crustal materials were recycled into their mantle sources through oceanic subduction in this period. Compared to the other Archean cratons elsewhere on Earth, the NCC is significantly deficient in komatiites and komatiite-related rocks, but it contains much higher proportions of the LREE-enriched basaltic rocks and calc-alkaline andesitic rocks. This difference suggests that the formation of the NCC was primarily driven by oceanic subduction though the mantle plume would locally operate at ca. 2.8 Ga in the western Shandong region. Large-scale subduction of the oceanic slab in the NCC would be initiated at ca. 2.65–2.60 Ga for mafic arc magmatism due to the convergence of heterogeneous oceanic plates.

Constraining the growth and evolution of the continental crust provides insight into the secular change of tectono-magmatic processes through time. Radiogenic isotope pairs such as 176Lu/176Hf are commonly used to track the growth rates of the continental crust. Previous studies utilizing global compilations of LuHf isotopes of zircon to query continental growth through time. However, we show that sample clustering and spatial bias lead to erroneous interpretations and casts doubt as to the representativeness of global zircon compilations. To ameliorate this issue, we apply a geographic declustering algorithm to remove the spatial bias in the nonrepresentative dataset. A more representative declustered dataset indicates that the continental crust grew much faster than previous assessments have proposed. We further speculate that the transition to modern-style tectonics (as heralded by the appearance of low temperature–high pressure metamorphism) was accompanied by little to no net continental growth and propose that continental growth may be a feature of pre-plate tectonic magmatic processes.

Accurate terrain models are critical for studying the formation and development of slot canyons. However, for slot canyon landforms, it is challenging to generate comprehensive and high-resolution morphological data by individual observation due to the inaccessibility of steep walls on either side and the complexity of the field observation environment, such as variable-slope terrain, partial vegetation cover, and lack of satellite signal. Off-the-shelf surveying techniques, including Unmanned Aerial Vehicles (UAV) photogrammetry and Backpack Mobile Laser Scanning (BMLS), facilitate slot canyon surveys and provide better observations. This paper proposes an integrated scheme to generate comprehensive and centimeter-resolution slot canyon terrain datasets (e.g., color point clouds, Digital Elevation Models (DEM), and 3D mesh) using BMLS and fine UAV photogrammetry. The results show that the fine flight of UAVs based on a rough model can avoid collision with obstacles or flying into restricted areas, allowing users to perform tasks faster and safer. Data integration of BMLS and UAV photogrammetry can obtain accurate terrain datasets with a Root Mean Squared Error (RMSE) of point cloud registration of 0.028 m. Such high-resolution integration terrain datasets reduce local data shadows produced solely by individual datasets, providing a starting point to revealing morphological evolution and genesis of slot canyons.

Tectonic switch from rift zones to subduction zones is common along convergent plate boundaries. While this process is susceptible to retrieving from Phanerozoic rock records, the difficulty has been encountered for Precambrian rock records because of the relative lack of characteristic geological signatures. Nevertheless, such a difficulty can be overcome by finding of specific geochemical signatures in ancient rock records. This paper reports our finding of low delta O-18 zircons from the Trans-North China Orogen (TNCO) in the North China Craton (NCC), where the tectonic switch would occur during the early to middle Paleoproterozoic in association with the amalgamation of supercontinent Columbia. A combined study of zircon U-Pb ages and Hf-O isotopes as well as whole-rock major-trace elements and Nd isotopes were carried out for magmatic rocks from the Taiyue complex in the southern part of the TNCO. Zircon U-Pb dating yields two episodes of magmatism at ca. 2.34-2.31 Ga and ca. 2.2-2.1 Ga. These magmatic rocks are dominated by the ca. 2.18-2.16 Ga granites, 2.18-2.17 Ga diorites and 2.17-2.11 Ga mafic-ultramafic cumulates that intruded the 2.34-2.30 Ga granites and diorites. The 2.2-2.1 Ga diorites, mafic-ultramafic cumulates, and the regional mafic dykes/intrusions exhibit continuously varying major element compositions, arc-like trace element patterns, and consistent zircon Hf and whole-rock Nd isotope compositions, indicating their derivation from the same suite of continental arc magmas. Such primitive arc magmas would evolve through fractionation and accumulation of pyroxenes and plagioclase into dioritic magmas. The two episodes of granites are similar in major and trace element compositions, generally belonging to alkali-calcic or calc-alkalic A-type granitoids. Although both groups show a small difference in their zircon Hf isotope compositions, they exhibit a big difference in their zircon O isotope compositions. The 2.31 Ga granites show variably low zircon delta???????O-18 values of 3.4-5.5 parts per thousand, mostly lower than normal mantle zircon values. The 2.18 Ga granites also exhibit variable zircon delta???????O-18 values from 3.6 to 6.0 parts per thousand, but mostly mantle-like values. It is inferred that the 2.31 Ga granites would acquire their low delta???????O-18 signatures from partial melting of the high-T seawater-hydrothermally altered Archean crust in an early Paleoproterozoic continental rift. This rift would extend for at least 300 km along the TNCO. The 2.18 Ga granites are closely associated with the 2.2-2.1 Ga diorites and mafic-ultramafic cumulates. They would be most likely to form through differentiation of the 2.2-2.1 Ga continental arc magma, with their low O-18 signatures being contaminated by the low delta???????O-18 2.3 Ga granites. The low ??????O-18 signatures in the 2.3 Ga and 2.18 Ga granites indicate that the southern part of the TNCO would have probably evolved from a lithospheric rift to an active continental margin during ca. 2.3-2.1 Ga.

The scientific siting of urban parks is critical for sustainable urban environment development, and this study aimed to identify suitable areas for future urban parks in Nanjing, China. This study has integrated geographic information systems (GIS) and fuzzy hierarchical analysis (F-AHP) in order to evaluate the suitability of the site selection of urban parks in Nanjing, China. Different physical, natural, environmental, accessibility, and human activity factors were evaluated in order to assess the suitability of a park site. The results revealed that 5% were highly suitable for urban park site selection, 36% were more suitable, 32% were moderately suitable, 19% were less suitable, and 8% were unsuitable for urban park site selection. The findings suggest that the areas that are highly suitable for urban park placement are located in the western and eastern parts of Nanjing. Carbon storage was the most important factor in the suitability of urban park site selection, followed by the normalized difference vegetation index (NDVI) and the heat-island effect. The methodology that has been adopted in this study helps to improve the methodological framework of combining F-AHP and GIS; in addition, generating urban park site selection maps assists planners and decision-makers in making scientific site selection decisions.

The large Bayanbaolege Ag polymetallic ore deposit is located in the Tuquan-Linxi Fe (Sn)-Cu-Pb-Zn-Ag-Nb (Ta) polymetallic metallogenic belt, which is an important part of the Great Xing’an Range metallogenic province, northeast China. The sulfide–quartz vein-type orebodies in the deposit are mainly hosted in the Cretaceous granodiorite porphyry and Late Permian Linxi formation. The U-Pb dating of the zircon from the post-ore diorite porphyrite yields an age of 124.8 ± 1.1 Ma, which constrains the mineralization time at the Early Cretaceous. The Sr-Nd isotope values (87Sr/86Sr)i = 0.708576~0.710536; εNd (t) = −0.51~+0.69; the Hf isotope values 176Hf/177Hf = 0.2827278~0.2830095, the εHf (t) = +3.1~+11.2, TDM2 = 615~1341 Ma of the metallogenic granodiorite porphyry. The Hf isotope values 176Hf/177Hf = 0.2828596~0.2829451, and the εHf (t) = +5.7~+8.8 of the diorite porphyrite, TDM2 = 827~1108 Ma, indicating that the ore-forming materials were the possible involvement of heterogeneous juvenile sources including moderately depleted mantle and newly underplated lower crust. The major and trace elements (including REEs) implied that these intrusions are the I-type granite and linked intimately to the westward subduction of the Paleo-Pacific Ocean plate. From these whole-rock major and trace elements and zircon U-Pb ages, as well as Sr-Nd-Hf isotope data, we conclude that the ore-associated I-type granites in the Bayanbaolege deposit formed in an extensional tectonic setting of the Early Cretaceous, and are compactly related to the retreat of the Paleo-Pacific Ocean subducted plate linked intimately to the westward subduction of the Paleo-Pacific Ocean plate rather than the closure of the Mongol–Okhotsk Ocean. Furthermore, by integrating geological background work and previous research work, implying the mineralization age of the Bayanbaolege deposit should have been formed in the 125–130 Ma.

大兴安岭南段罕苏木地区出露大面积的二长花岗岩,为了正确认识该岩体的形成时代及其伸展构造作用,本文采集相关样品,对罕苏木地区出露的二长花岗岩体开展了岩相学、LA-MC-ICP-MS锆石年代学和Hf同位素分析研究.研究结果表明:罕苏木地区二长花岗岩岩性为微细粒斑状含角闪黑云二长花岗岩和细粒斑状含黑云二长花岗岩,具有斑状和似斑状结构,块状构造.二长花岗岩中的锆石为岩浆成因,测得206Pb/238U年龄的加权平均值为(136±1)Ma(MSWD=1.4),属于早白垩世晚期岩浆活动的产物.这一结果与研究区及周边,甚至是与区域上中国东北地区114～145 Ma岩浆活动相吻合,都属于同一岩浆活动阶段的产物.罕苏木地区二长花岗岩锆石的εHf(t)值均为正值,变化范围为7.1～14.4,并且具有较年轻的二阶段模式年龄,TDM2为324～959 Ma.年轻的Hf同位素模式年龄,暗示在新元古代—晚古生代曾发生一次重要的地壳增生事件.结合区域地质,表明研究区二长花岗岩的岩浆可能是来源于从亏损地幔中新增生的年轻地壳发生部分熔融的产物,在侵位过程中受到了地壳或岩石圈地幔的混染,可能形成在造山后岩石圈伸展环境下,与古太平洋板块向欧亚大陆俯冲有关.