The North China Craton, South China Craton, and Tarim Craton are three well-known Precambrian cratons in China, which preserve valuable records of continental formation, crust-mantle interaction, supercontinent cycle, and the coupled evolution of inner and outer spheres of the Earth over the past ca. 3.8 Ga. Although significant achievements in Precambrian geology of these cratons have been obtained in recent years, some key questions such as the identification of Eoarchean continental nuclei, the quantification of Archean crustal growth and reworking, the anatomy of Paleoproterozoic orogenic belts, and the reconstruction of Precambrian supercontinents, remain unresolved. To celebrate the 50th anniversary of Precambrian Research and address these uncertainties, this special issue collects 55 original contributions and critical reviews. These studies integrate stateof-the-art techniques to present novel data and synthesize recent research progress, spanning long period from the Paleoarchean to Neoproterozoic. The research fields cover magmatism, metamorphism, metallogeny, geodynamic evolution, and paleoenvironment perturbation and so on. Accordingly, this special issue not only provides a timely overview of Precambrian geology in Chinese cratons, but also offers new lines of evidence to resolve some long-standing controversies, which would receive great interests from the global community and promote further international dialogue on the early Earth's evolution.

There is increasing evidence that the redox state of the Mesoproterozoic (1.6-1.0 Ga) ocean was much more dynamic than previously recognized, although the trajectory of Earth surface oxygenation over this immense interval of time remains poorly understood. In order to further constrain oceanic oxygenation dynamics, we present a high-resolution, multi-proxy geochemical study of carbonate-rich rocks from the Mesoproterozoic Gaoyuzhuang Formation, North China Craton, which represents a critical Mesoproterozoic section due to its association with the earliest known, decimetre-scale eukaryotes. Combined with Fe-speciation analyses, our approach utilizes sequential leaching to target the primary carbonate-phase, and utilizes an improved enrichment factor calculation for application of U (U-EF*) and Mo (Mo-EF*) systematics to carbonate-rich rocks. Rather than recording a series of discrete oxygenation pulses, our data suggest a prolonged interval of enhanced oxygenation, from the upper part of Member I to the lower part of Member III in the Gaoyuzhuang Formation. However, this only oxygenated surface waters to shallow subtidal depths. Subsequently, a more distinct oxygenation pulse occurred below the Gaoyuzhuang fossil horizon of Member III (similar to 750 m), which oxygenated the water column to around storm wave base. However, this enhanced oxygenation appears to have ceased during deposition of Member IV in the Gaoyuzhuang Formation, with a decline in surface water oxygenation, at least on a local or regional scale, raising uncertainty over the broader scale trajectory of Earth surface oxygenation. Based on the oceanic redox evolution recorded by the whole formation, we speculate that the prolonged stable oxygenation of shallower waters, rather than a discrete oxygenation event, may have permitted the evolution of the large-scale Gaoyuzhuang eukaryotes.

The origin of peraluminous ferroan (A-type) granites remains debated, particularly regarding the contribution of metasedimentary versus metaigneous sources. This study reports the first discovery of late Paleoproterozoic (ca. 1822 Ma; zircon SHRIMP U–Pb ages) garnet-bearing peraluminous ferroan granites in the Trans-North China Orogen of the North China Craton (NCC). These granites are characterized by high SiO2 (74.05–75.98 wt%), K2O/Na2O (1.04–1.34), Al2O3/(CaO + Na2O + K2O) (A/CNK = 1.07–1.13), FeOtotal/(FeOtotal + MgO) (0.81–0.87), and 104 × Ga/Al ratios (2.72–2.90), typical of peraluminous ferroan granites. Garnets in these granites contain biotite, plagioclase, and quartz mineral inclusions with geochemical characteristics (e.g., high Fe and low Mn) that resemble those of peritectic garnets formed via biotite breakdown during the anatexis of metasedimentary rocks. The garnet-bearing peraluminous ferroan granites have high formation temperatures (>830–850 ℃) and low oxygen fugacities (FMQ − 3.64 to + 0.12). All these features combined with phase–equilibrium modeling indicate that they were generated by high-temperature partial melting of pelitic granulites. Their low δ18O values (1.73 ‰–3.01 ‰) and enriched Nd–Hf isotopes (εNd(t) = –5.43 to –5.10; εHf(t) = –4.9 to –1.7) are consistent with anatexis of a previously melted, hydrothermally altered, residual metasedimentary crust. A regional compilation reveals that a considerable volume of peraluminous ferroan granites in the NCC may form via the partial melting of pelitic granulites. Therefore, greater caution should be exercised when interpreting the genesis of peraluminous ferroan granites. Importantly, the generation of peraluminous ferroan granites appears to be closely linked to hot collisional orogens where high thermal gradients facilitate melting of metasedimentary residues. These findings highlight peraluminous ferroan granites as a key petrogenetic indicator for tracing the thermal evolution and crustal reworking in high-grade metasedimentary terrains.

The Archean to Paleoproterozoic Earth underwent significant changes in surface, crust and mantle systems, yet interactions between these reservoirs remain poorly constrained. Sanukitoids are generated by mantle-crust interaction, and thus provide a record of early Earth recycling processes. Here we combine Barium (Ba) and Magnesium (Mg) stable isotopes with radiogenic isotopes and elemental data from 3.4-2.1 Ga sanukitoids to trace crust-mantle interaction across this critical interval. Archean sanukitoids display highly variable Ba and Mg isotopic compositions, suggesting contributions from altered ocean crust, hydrothermal barite and/or sediment. In contrast, Paleoproterozoic sanukitoids show uniformly lighter isotopic signatures, closely resembling Phanerozoic arc magmas influenced by pelagic sediments. Importantly, Ba isotope fractionation before the Great Oxidation Event indicates local sulfate production and oxidized conditions in sanukitoid sources. These results reveal variable recycling of locally-oxidized ocean crust since the Paleoarchean, and confirm sanukitoids as a key archive of early Earth crust-mantle dynamics.

Various types of arc magmatic rocks occur globally within subduction zones. A conventional metasomatized mantle wedge melting model is typically employed to explain the formation of diverse arc magmatic rock types. In this model, the mantle wedge is metasomatized by fluids or melts derived from the subducting slab, leading to modifications in its geochemical composition. However, the geochemical data from the Late Cretaceous Namling gabbro-monzonite suite, in conjunction with coeval adakitic or adakitic-like rocks in southern Tibet, suggest that these different types of arc magmatic rocks were not originated from partial melting of a mantle wedge metasomatized by melts or fluids. Instead, the elemental and isotopic data provide robust support for a melange melting model. The physically mixed melange rocks, which incorporate components from oceanic basalts, sediments, and mantle wedge peridotites, were dragged down to varying depths, causing eventual melting and subsequently generating the different types of Late Cretaceous arc magmatic rocks in southern Tibet. Partial melting of physically hybrid melanges at relatively shallow depths likely generated the normal arc magmas that are parental to the Late Cretaceous Namling gabbro-monzonite suite, with no garnet retained in the residual mineral assemblage. Meanwhile, melanges dragged down to relatively greater depths underwent partial melting with garnet as part of the residual mineral assemblage, likely producing the Late Cretaceous adakitic or adakiticlike rocks. The melange melting was likely induced by hot asthenospheric upwelling caused by the retreat of the northward-subducted Neo-Tethyan oceanic plate during the Late Cretaceous. Therefore, partial melting of melange materials provides an alternative mechanism for the generating of different types of arc magmas in global subduction zones.

Crust-mantle architecture in large igneous provinces (LIPs) controls magma generation and crustal growth. The coeval gabbro and monzonite in the inner zone of the Emeishan Large Igneous Province (ELIP) provide a key opportunity. They display different whole-rock and mineral compositions, indicating different sources and melting conditions. The gabbro displays moderate TiO2 and MgO contents, with Ti/Y ratios of 408-413. Its elevated Nb/Ta and Zr/Hf ratios, evolved zircon Hf isotope, and apatite chemistry suggest a volatile-poor primitive melt, which was derived from the melting of sub-continental lithospheric mantle. The monzonite displays high Zr and Nb contents, TFeO/MgO and 10,000 & times; Ga/Al ratios, indicating high-temperature melting of mafic lower crust, the high Sr contents suggest plagioclase incorporation into the melts. Its relatively depleted isotopic compositions (epsilon Nd(t) = +3.2 to +3.7; epsilon Hf(t) = +0.87 to +0.88) reveal a juvenile crust source region. Apatite in the monzonite indicates a volatile-rich melt, supporting a high-temperature crustal melting origin. This geochemical dichotomy illuminates a two-stage crustal evolution model: (1) melting of plume-modified lithospheric mantle to generate the gabbro, followed by (2) thermal remelting of the juvenile mafic crust to form the monzonite. Such plume-induced crust-mantle interaction offers a window into understanding crust-mantle architecture in global LIPs.

The South China Block (SCB) was formed through the amalgamation of the Yangtze and Cathaysia blocks along the Sibao orogen (also known as the Jiangnan orogen) during the early Neoproterozoic assembly of the Rodinia supercontinent. Although possessing records of both the assembly and breakup of Rodinia, the position of the SCB in Rodinia remains debated, mainly due to disagreement on the tectonic settings of the 827 +/- 22 Ma episode magmatism along the orogen. The magmatism has been interpreted either as subduction-related, placing SCB on the margin of Rodinia, or as plume-related, suggesting a central position linking Australia and Laurentia. In this study, we investigate a gabbro-peridotite complex in the central Sibao orogen, with the peridotite showing cumulate textures and the gabbro giving a zircon U-Pb crystallization age of 812.8 +/- 5.7 Ma. These samples, together with a compilation of 560 published mafic-ultramafic and granitic samples within the 827 +/- 22 Ma episode from the Sibao orogen, define cumulate lines of descent characterized by a continuous decline in Mg# with increasing SiO2, rather than the Z-shaped Mg#-SiO2 trend diagnostic of hydrous, subduction-related magmas, which is consistent with crystallization from anhydrous melts. This indicates that the 827 +/- 22 Ma episode magmatism originated from a dry mantle source, inconsistent with an active subduction setting. Mantle potential temperatures estimated from near-primary high-MgO basalts (MgO up to 17.5 wt%, Mg# up to 75, showing equilibrium with mantle) within this episode exceed 1525 degrees C, significantly above the ambient mantle potential temperature expected at similar to 827 Ma (1350-1410 degrees C), pointing to an anomalously hot mantle source. Initial Os-187/Os-188 isotopes of the studied cumulative peridotites (0.1376-0.1642) and coeval mafic-ultramafic rocks (0.1100-0.4191) indicate assimilation-fractional crystallization (AFC) processes involving asthenospheric components (plume), continental lithospheric mantle, and crustal material. This is consistent with plume underplating and interaction with the pre-existing subduction-modified lithosphere and overlying crust. Coeval plume-related magmatism is also documented elsewhere within the SCB beyond the Sibao orogen, e.g., the Bikou flood basalts, further supporting a regional-scale thermal anomaly. Collectively, these observations are best explained by mantle plume activity, supporting a central position for the SCB in Rodinia.

The Taihua Complex, located on the southern margin of the Trans-North China Orogen (TNCO), North China Craton, is a critical region for decoding tectonic evolution of the TNCO. In this study, an integrated investigation of petrology, phase equilibrium modelling and LA-ICP-MS zircon U-Pb dating is undertaken for the staurolite-bearing metapelitic schist in the Lushan Taihua Complex. Petrographic observations reveal a four-stage metamorphic evolution, including: (1) A pre-peak (M1) assemblage consisting of the garnet core and its mineral inclusions of staurolite, plagioclase, biotite, quartz, ilmenite and rutile; (2) The pressure peak (M2) assemblage represented by the inclusions of plagioclase, biotite, quartz, ilmenite and rutile within garnet rims, and the presence of kyanite pseudomorphs after sillimanite, which is confirmed by the Raman spectra; (3) The decompression stage (M3) characterized by the transformation from kyanite to sillimanite as well as partial replacement of rutile by ilmenite; and (4) the final stage (M4) marked by the fine-grained assemblage of biotite + plagioclase + quartz +/- sillimanite, locally surrounding the garnet porphyroblasts. Phase equilibrium modelling results suggest that the metapelitic schist experienced the high-amphibolite facies metamorphism, with P-T conditions approaching 654 similar to 661 degrees C/8.7 similar to 9.1kbar (M1) and 751 similar to 766 degrees C/10.7 similar to 11.1 kbar (M2), followed by a decompression with minor heating to 778 similar to 795 degrees C/7.2 similar to 7.9 kbar (M3), and finally, the rocks underwent a cooling process until 699 similar to 702 degrees C/7.1 similar to 7.2 kbar (M4). Thus, a clockwise P-T path is retrieved. Zircon U-Pb dating yields a weighted mean Pb-207/Pb-206 age of 1883 +/- 9 Ma, interpreted as the time of the post-peak cooling. Therefore, it can be inferred that the Taihua Complex has been involved in the collision between the Western and Eastern Blocks of the NCC in the late Paleoproterozoic. Based on previously published data, we propose that the Taihua Complex records the pressure peak metamorphic ages of ca. 1.95 Ga and cooling ages of ca. 1.93(1.92) similar to 1.80 Ga. The main crustal thickening process possibly occurs at ca. 1.95 Ga, followed by uplifting, and final cooling from ca. 1.93(1.92) - 1.80 Ga.

The northeastern (NE) Tibetan Plateau is extruding eastward at a rapid rate (∼15 mm a-1), but the role of the upper mantle in this process remains unclear. Early-Miocene primary melilitites from the leading edge of the extruding plateau provide critical insights into the upper mantle dynamics. Geochemical and Sr-Nd-Pb-Os isotopic data, supported by experimental melt comparisons, reveal that these melilitites originate from a hybrid source of CO2-bearing mantle source, probably dominated by peridotite and pyroxenite/wehrlite lithologies. This is consistent with carbonate minerals found in mantle xenoliths (peridotite + pyroxenite) entrained within the melilitites. Geothermobarometric calculations indicate magma generation at 116-135 km depth, below the lithosphere-asthenosphere boundary (∼112 km) constrained by xenoliths and seismic data. Isotopic data trace the carbon origin to a carbonated lithosphere associated with the 150-km-thick eastern tectonic blocks. Recent seismological studies suggest that eastward-flowing asthenosphere beneath the northeastern Tibetan Plateau is actively eroding the thicker lithosphere (150-200 km) of the eastern blocks. We propose that this asthenospheric flow not only thins the lithosphere but also mobilizes carbon from the eastern carbonated lithosphere into generating the melilitite, likely via edge-driven convection. The resulting melilitite compositions is therefore a petrological record of these dynamic processes. This study highlights the critical role of upper mantle processes-astenospheric flow and lithospheric erosion-in driving the eastward extrusion of the Tibetan Plateau. It also underscores the importance of carbon mobilization in understanding mantle carbon cycling during continental collision.

Porphyry systems in continental collision belts contain substantial copper (Cu) and molybdenum (Mo) resources. However, unraveling their magma source compositions poses a significant challenge due to the superposition of previous oceanic subduction fingerprints. We report Mo isotope data on post-collisional (Oligocene-Miocene) Cu (Mo)-bearing porphyries (CBPs) and related barren-ore rocks (including Eocene granites and Miocene high-Mg diorites and ore-barren granites) in the eastern Gangdese belt, southern Tibet. The Eocene granites with high delta 98/95Mo values (0.37-0.58 %o) and K2O, Th contents originated from anoxic sediment-modified juvenile lower crust related to oceanic subduction. The Miocene high-Mg diorites with shoshonitic characteristic have extremely low delta 98/95Mo of -1.20 %o to -0.92 %o, possibly deriving from a lithospheric mantle metasomatized by slab melts from subducted Indian crust. By contrast, the CBPs show moderate and variable delta 98/95Mo values (-0.85 %o to 0.34 %o), reflecting either source or magma mixing of juvenile Asian lithosphere and subducting continental crust-derived melt components. The Miocene ore-barren granites have element compositions similar to the CBPs but are more Na-rich and have lower Th contents, slightly depleted Sr-Nd isotopes, and heavy Mo isotopes (-0.14 %o to 0.23 %o), implying lower amounts of continental components in their magma source. Our Mo isotope data thus provides solid evidence for the incorporation of subducted Indian slab melts into the CBP magmas. Furthermore the CBPs contain more Indian components than the Miocene ore-barren granites, suggesting that the input of subducted continental crust melts is critical in the formation of post-collisional porphyry systems possibly by oxidizing the overlying fertile lithosphere.

Neoarchean TTG and K-rich granitoids in the Yinshan Block provide a key to understanding the crustal evolution of the North China Craton (NCC), such as the change of continental crust composition, the micro-continent collision and the cratonization. Zircon U-Pb dating suggests that these Neoarchean TTG and K-rich granite rocks were emplaced at 2.7-2.5 Ga and similar to 2.5 Ga, respectively. The TTG rocks have low Cr, Co, and Ni contents and Mg-# values, indicative of a crustal source. The similar to 2.7 Ga Kuluedianlisu granodiorites have positive epsilon(Hf)(t) values ranging from +6.6 to +9.3, with crustal model ages (TDMC) of 2.59-2.75 Ga, indicating that they were formed by partial melting of juvenile lower crust. The Hejiao and Dajitu TTG rocks show lower positive epsilon(Hf)(t) values (+3.4 to +5.6) and older crustal model ages (T-DM (c) = 2.53-2.83 Ga) than the Kuluedianlisu granodiorites, demonstrating an origin of partial melts from the pre-existing lower crust. The Rentaihe K-rich granites show higher Sr/Y and (La/Yb)(N) ratios which similar to the high pressure sodium TTG rocks. They have low epsilon(Hf)(t) values varying from -1.7 to +4.9, with crustal model ages (TDMC) from 2.7 to 3.1 Ga. Therefore, it is reasonable to suggest that the Rentaihe K-rich granites were produced by remelting of preexisting TTG rocks. According to the complied Hf isotopic compositions, the crustal model age peaks at 2.6 - 2.7 Ga and 2.7 - 2.8 Ga, indicating a crucial period for crustal growth in the Western Block. In the Neoarchean, the K2O/Na2O, the A/CNK ratios, and delta O-18 values increased from similar to 3.1 Ga to similar to 2.5 Ga, indicating a rise of crustal maturity. The crustal thickness simulations show that the crust of the NCC thickened continuously from similar to 3.1 Ga to 2.5 Ga. Thus, we conclude that the increasing of crust thickness is induced by the amalgamation of micro-continents through collision and the more buried supracrustal material into deep crust. Subsequent partial melting of the deep crust generated magmas with high delta O-18 values and thus resulted in the formation of more mature continental crust.

Komatiite, characterized by high MgO content and low H2O concentration, is crucial to understanding the Archean magma processes and crust-mantle differentiation. Although well preserved in most cratons, Archean komatiites are scarce in the North China Craton (NCC). The Sujiagou komatiites, as the most typical Archean komatiites in China, were exposed in the Luxi terrane, but their geochronology and petrogenesis types remain controversial. In this study, our new Re-Os data indicate the Sujiagou komatiites originated before 2.90 Ga. The felsic zircons discovered in the komatiites, coupled with Nb-Th-La simulation, suggest similar to 2 % crustal contamination of the komatiites. Thus, the least-altered, spinifex- and massive-texture samples that underwent unconspicuous crustal contamination were selected as proximate proxies for the primary magma composition. The Al/Ti ratios of the Sujiagou komatiites are comparable to or slightly exceed those of chondrite, suggesting they were aluminium-undepleted komatiites and formed at similar to 8 GPa. The primitive mantle-normalized rare earth element (REE) patterns show depleted light REE and flat heavy REE, suggesting approximately 50 % partial melting based on REE simulation. Additionally, the komatiites exhibit slightly depleted Os isotope ratios, with an average gamma(Os(t)) value of -0.3, indicating the magma source is comparable to or slightly depleted to chondrite. Simulation of the relevant Nb/Zr and La/Sm-PM ratios further suggests the mantle source became slightly depleted due to ca. 1 % melt extraction. Furthermore, the Mg isotopic composition of the Sujiagou komatiites (delta Mg-26 = -0.23 +/- 0.03 parts per thousand) is consistent with that of the primitive mantle, indicating the absence of recycled carbonate material in the mantle source. Both Re-Os and Mg isotopes reveal limited involvement of crustal or carbonate material in the mantle source, implying the absence of oceanic slab subduction in the Luxi terrane during this time. The formation of the Sujiagou komatiites can be attributed to a hot mantle plume, resulting from high potential and eruption temperature. The identification of felsic zircons in the Sujiagou komatiites indicates the presence of an ancient continental nucleus in the Luxi terrane. Combined with the spatially adjacent terrigenous clastic sedimentary rocks, we suggest that the Sujiagou komatiites erupted most likely in a continental margin of the old terrane.

The Paleoproterozoic tectonic evolution of the Trans-North China Orogen of the North China Craton (NCC) has long been controversial. One of the key factors is the difference in the understanding of the A-type granites in the middle Paleoproterozoic. In this study, whole-rock geochemistry and Nd isotope, zircon U-Pb and Hf-O isotope, and zircon H2O content are reported for middle Paleoproterozoic syenogranite, monzogranite, and alkali-feldspar granite in the Wutai area. LA-ICP-MS zircon dating results show that the intrusions have emplacement ages from 2117 to 2133 Ma. The 2.1 Ga granites in the Wutai area exhibit elevated SiO2 (72.20-78.01 wt%), K2O + Na2O (7.32-8.78 wt%) and Zr + Nb + Y + Ce (> 528 ppm) concentrations, high FeOt/(FeOt + MgO) (0.78-0.89), 10000*Ga/Al (> 3) and K2O/Na2O (1.0-1.9) ratios, low TiO2/MgO ratios (0.4-1.4), and significant depletion of Ba, Sr, Eu, as well as high zirconium saturation temperatures (785-892 degrees C), showing typical characteristics of aluminous A-type granites. The samples display characteristics of relatively enriched zircon Hf isotopes (epsilon Hf(t) = -5.6 to + 2.7), whole-rock Nd isotopes (epsilon Nd(t) = -2.9 to + 0.3), and old two-stage Hf model ages (2.56-3.05 Ga) similar to those of Neoarchean TTG gneisses in the same area. Furthermore, the oxygen isotope composition of zircon (delta O-18 = 4.7 to 7.4 parts per thousand) are lower than those of zircons from the A-type granites derived from meta-sedimentary melts, indicating that the A-type granites are predominantly derived from the partial melts of Archaean TTGs. These granites contain both ilmenite and magnetite, indicating a relatively oxidizing environment. Zircon (log(fO(2)) = -14.9 to - 7.8) and biotite (log(fO(2)) = -13.5 to - 11) also show high oxygen fugacity. The water content of zircon is 104-842 ppm, with an average of 414 ppm, showing a relatively wet environment. These oxidised and water-rich A-type granites are likely to form in a back-arc extensional setting. Combined with the published NCC data, the Trans-North China Orogen is inferred to be an Andean-type continental arc setting in the middle Paleoproterozoic, suggesting the possibility of continuous subduction in the Paleoproterozoic.

Composite granitic pluton with distinct units is a potential target for identifying its detailed magma evolution. Here, we present zircon U-Pb ages and Hf isotope, whole-rock major and trace element compositions and Nd-Pb isotopes of the Wangxiang composite pluton, South China. New ages obtained show that these rocks were generated in Late Jurassic (ca. 156–158 Ma). The rocks are divided into low silica (SiO2 < 67 wt.

本文总结了现阶段前板块构造与大陆起源研究的三大重要进展:（1）提出了地幔柱构造、重力凹沉构造和热管构造的前板块构造模式;（2）揭示了非板块构造与板块构造的标志;（3）发现了地球早期层圈演化地质记录.但是,现有的前板块构造并不能完美解释太古宙大陆的起源,板块构造在解释大陆起源与演化方面也遇到重大挑战.此外,阐述了我国开展前板块构造与大陆起源研究的必要性、研究优势及风险,并凝练了目前前板块构造与大陆起源研究的关键科学问题:（1）地球是先有陆还是先有板块构造;（2）海陆的形成是否同步;（3）冥古宙陆壳和英云闪长岩-奥长花岗岩-花岗闪长岩（tonalite-trondhjemite-granodiorite, TTG）的起源.基于学科发展,提出动力学热模拟和比较行星学在前板块构造与大陆起源研究中的重要性.在此基础上,认为未来5～10年前板块构造与大陆起源的研究重点领域为:（1）大陆的起源及其对早期地球环境和生命的影响;（2）前板块构造样式及其形成机制;（3）太古宙的构造热体制及热演化;（4）前板块构造与类地行星演化.

Magmatic rocks in the North China Craton (NCC) are crucial to unraveling the tectonic background during the tectono-magmatic lull (TML, 2.45-2.20 Ga) and to constraining the initiation of plate tectonics. In this study, previously published zircon U-Pb-Hf-O data and whole -rock geochemistry are collected from the early Paleoproterozoic felsic intrusive rocks in the southern Trans -North China Orogen (TNCO) and new data presented. The formation ages and petrogenesis of the early Paleoproterozoic felsic intrusive rocks in the southern TNCO are summarized to constrain the tectonic setting during the TML. Zircon U-Pb geochronology of the tonalite-trondhjemite-granodiorite (TTG) gneisses yielded intrusive ages of -2.3 Ga and -2.2 Ga. Geochemically, the gneisses can be classified as -2.3 Ga high -Al and -2.2 Ga low -Al types, and were likely derived from the partial melting of pre-existing lower crust at medium and low pressure, respectively. The heavy rare earth depletion and have high Sr/Y and La/Yb values of the -2.3 Ga TTG gneisses indicates that they were derived from the partial melting of thickening lower crust in the garnet -hornblende phase, which is consistent with a gradual thickening of the crust. The potassic granitoids are geochemically divided into I -type and A -type granites and have early Paleoproterozoic ages at -2.3 Ga and -2.27 Ga. Zircon U-Pb geochronology of the dioritic gneisses yielded intrusive ages of -2.3 Ga. These potassic granitoids and dioritic gneisses were generated by the partial melting of ancient basement rocks, with variable degrees of juvenile contributions. Considering the large variety of zircon epsilon Hf(t) values, and Sr/Y and (La/Yb)N ratios obtained for the early Paleoproterozoic felsic intrusive rocks, the crustal thickening that occurred via tectonic compression prior to -2.3 Ga is most likely due to convergence. The high 818O and low 818O values in the southern TNCO may have been the result of slab subduction, which can effectively transfer surface material directly or indirectly to the lower crust, and the TTGs that formed as a result of the subsequent partial melting inherited the high 818O characteristics to varying degrees. Glacial meltwater is an important source of low 818O fluids and a large number of rift events developed during the 2.5-2.4 Ga interval. The resulting fractured environment provided sufficient space for the infiltration of surface water, and rocks with low 818O characteristics are likely produced by the remelting of crustal rocks that have been thermally altered by surface water or atmospheric hydrothermal processes. Combined with evidence such as the Paleoproterozoic Alaska -type intrusive rocks, diabases, sanukitoids and sedimentary rocks, the TNCO is proposed to have been in a subduction compression setting at -2.3 Ga. Meanwhile, the alkaline and related elements (such as Rb, Th, Ba and Nb), K2O/Na2O ratios, and zircon 818O values of the magmatic rocks increased significantly during the TML, which indicate that plate subduction started prior to -2.3 Ga. The difference in the intensity of the magmatism during the TML may be related to continental freeboards in different regions-