We report high-precision K isotopes, apatite U–Pb ages, whole-rock elements and Sr–Nd isotopes for the Saima nephelite syenite in the North China Craton. Trace-element and Sr–Nd–Hf–O isotope data indicate the presence of subducting sediments in the source region, while K isotopic compositions show a narrow range between –0.54 ‰ and –0.28 ‰, with an average of –0.41 ± 0.06 ‰, identical to the value of the asthenosphere. The nearly identical K isotopic compositions are low probability events compared with the K isotopic compositions of island arc lavas reported previously (–1.55 ‰ to +0.2 ‰). Although crustal contamination is consistent with the Sr–Nd–K isotopic data, alternatively we propose that the isotopic data also reconcile with the interaction between cratonic roots and the underlying convective asthenosphere, if this interaction is over prolonged periods of time. Numerical simulations successfully reproduced the observed data, if the metasomatism of the lithospheric mantle root, the source of the Saima alkaline rocks, occurred 500 Ma ago. Our study reveals that the isotopic compositions of fast-diffusion components in a lithospheric mantle metasomatized by ancient subducting melts can be effectively homogenized by convective asthenosphere through diffusion over a long time interval.

Daqingshan is located in the northwestern North China Craton where late Neoarchaean supracrustal rocks occur widely, but where magmatic zircon ages have rarely been reported for plutonic rocks. In this study, we report SIMS U–Pb zircon ages and Hf isotope, whole-rock element and Nd isotope compositions for 12 magmatic samples, including TTG, quartz monzonitic and monzogranitic gneisses, and meta-gabbroic and dioritic rocks. They have magmatic zircon ages of 2530–2469 Ma; some samples have ages of <2.48 Ga likely influenced by late Palaeoproterozoic tectonothermal events, making their ages less reliable. TTG gneisses have low Sr/Y and La/Yb ratios, with whole-rock ϵNd(t) and in situ magmatic zircon ϵHf(t) values of +1.2 to +2.4 and −1.1 to +6.2, respectively. Quartz monzonite and monzogranite gneisses and gabbroic to dioritic rocks have similar Nd–Hf isotope compositions to the TTG gneisses. The absence of zircon >2.6 Ga in the early Precambrian rocks suggests that the Sanggan Group may have formed in an oceanic environment, whereas the TTG rocks formed as a result of partial melting of the basaltic rocks of the Sanggan Group under relatively low-pressure conditions. Combined with previous studies, the main conclusions are that in the Daqingshan area, late Neoarchaean magmatism was widespread, the late Mesoarchaean – early Neoarchaean was an important period of juvenile continental crustal growth, and the late Neoarchaean supracrustal and plutonic rocks most likely formed in an arc environment. These are common signatures for Neoarchaean crustal evolution throughout much of the North China Craton, and also globally.

The Songling and Majiayu peridotite blocks occur in the Eastern Block, North China Craton (NCC). Geothermobarometry data show that the Songling peridotites began exhumation from a depth of c. 70 km (c. 23 kbar). During exhumation, the Songling peridotites were intruded by an upper-crust-derived, high-δ18O (up to +7.28‰ in zircon) trondhjemitic dyke at 2.47 Ga and experienced granulite-facies metamorphism. The Songling peridotites have hybrid mantle wedge (HMW) -like high SiO2 (> 45 wt%), high FeOt (c. 10 wt%) content, high modal orthopyroxene abundance (> 35%) and high ϵNd(t) (+18.4 to +21.4), which were generated by the reaction between peridotite and eclogite-derived melts. The clinopyroxenes from the Songling peridotites were in equilibrium with a Nb-, Zr- and Ti-depleted arc-like magma. The Majiayu peridotites are characterized by depletion of Nb, Zr and Hf and are highly enriched in FeOt, Th and light rare earth elements (LREEs), which can be interpreted as an open system reaction between hydrous melts and fore-arc mantle peridotites. These two peridotite blocks are considered to be arc-related mantle peridotites that experienced melt extraction and metasomatism in different styles. They were exhumed to the north margin of the North China Craton during the c. 2.47 Ga arc–continent collision along the Zunhua structural belt.

A suite of Jurassic–Cretaceous migmatites was newly identified in the Liaodong Peninsula of the eastern North China Craton (NCC). Anatexis is commonly associated with crustal thickening. However, the newly identified migmatites were formed during strong lithospheric thinning accompanied by voluminous magmatism and intense deformation. Field investigations show that the migmatites are spatially associated with low-angle detachment faults. Numerous leucosomes occur either as isolated lenses or thin layers (dykes), parallel to or cross-cutting the foliation. Peritectic minerals such as titanite and sillimanite are distributed mainly along the boundaries of reactant minerals or are accumulated along the foliation. Most zircons show distinct core–rim structures, and the rims have low Th/U ratios (0.01–0.24). Zircon U–Pb dating results indicate that the protoliths of the migmatites were either the Late Triassic (224–221 Ma) diorites or metasedimentary rocks deposited sometime after c. 1857 Ma. The zircon overgrowth rims record crystallization ages of 173–161 Ma and 125 Ma, which represent the formation time of leucosomes. These ages are consistent with those reported magmatic events in the Liaodong Peninsula and surrounding areas. The leucosomes indicate a strong anatectic event during the Jurassic–Cretaceous period. Partial melting occurred through the breakdown of muscovite and biotite with the presence of water-rich fluid under a thermal anomaly regime. The possible mechanism that caused the 173–161 Ma and 125 Ma anatectic events was intimately related to the regional crustal extension during the lithospheric thinning of the NCC. Meanwhile, the newly generated melts further weakened the rigidity of the crust and enhanced the extension.

Whole-rock major and trace elements and Hf isotopes of magmatic zircons of tonalite–trondhjemite–granodiorite (TTG) rocks with different ages (2.9, 2.7 and 2.5 Ga) from the three blocks (the Eastern Block, Western Block and Trans-North China Orogen) of the North China Craton were compiled to investigate their respective petrogenesis, tectonic setting and implications for crustal growth and evolution. Geochemical features of the 2.5 Ga TTGs of the Eastern Block require melting of predominant rutile-bearing eclogite and subordinate garnet-amphibolite at higher pressure, while the source material of the 2.7 Ga TTGs is garnet-amphibolite or granulite at lower pressure. The 2.5 Ga TTGs have high Mg#, Cr and Ni, negative Nb–Ta anomalies and a juvenile basaltic crustal source, indicating derivation from the melting of a subducting slab. In contrast, features of the 2.7 Ga TTGs suggest generation from melting of thickened lower crust. The 2.5 and 2.7 Ga TTGs in the Trans-North China Orogen were formed at garnet-amphibolite to eclogite facies, and the source material of the 2.5 Ga TTGs in the Western Block is most likely garnet-amphibolite or eclogite. The 2.5 Ga TTGs in the Trans-North China Orogen and Western Block were generated by the melting of a subducting slab, whereas the 2.7 Ga TTGs in the Trans-North China Orogen derived from melting of thickened lower crust. The Hf isotopic data suggest both the 2.5 and 2.7 Ga TTG magmas were involved with contemporary crustal growth and reworking. The two-stage model age (TDM2) histograms show major crustal growth between 2.9 and 2.7 Ga for the whole North China Craton.

The Taihangshan Mountain Belt, in the central North China Craton, represents an important crustal and tectonic boundary. To explore the complex tectonic evolution of this area during the Mesozoic–Cenozoic, we gathered zircon and apatite (U–Th)/He thermochronology data along a vertical transect (elevation of 630−1584 m) of the northern part of the Taihang Mountain Belt. From our data, we observed three separate rapid cooling phases that occurred at 100 Ma, 50−40 Ma and 27 Ma. Combined with previously published geochronological ages, we suggest that the uplift of the Taihang Mountain Belt initiated during the Jurassic and experienced multiphase rapid uplift from the Cretaceous to the Cenozoic. The early Cretaceous rapid cooling/uplifting events are widespread in the North China Craton and are caused by the collision between the Okhotomorsk Block and the East Asian continental margin. The Eocene and Oligocene rapid cooling events correspond to the initial rifting and thermal subsidence of the Bohai Bay Basin, indicating a coupling between the creation of basins and mountains.

We report new U–Pb zircon age data, zircon in situ oxygen isotope, mineral chemistry, whole-rock geochemistry and Sr–Nd isotopic compositions from the Early Devonian ultrapotassic Gucheng pluton in the North China Craton, and discuss its petrogenesis. The Gucheng pluton is exposed in the northern part of the North China Craton and forms a composite intrusion, consisting of K-feldspar-bearing clinopyroxenite, clinopyroxene-bearing syenite and alkali-feldspar syenite. Mineral phases in these lithologies include clinopyroxene (Wo43–48En19–35Fs18–38), sanidine (An0Ab3–11Or89–97), and subordinate titanite, andradite and Na-feldspar. These rocks show homogeneous Sr but variable Nd isotopic compositions, and have relatively high zircon in situ oxygen isotopes (δ18O = 5.2–6.7). The Gucheng plutonic rocks formed through fractional crystallization and accumulation from ultrapotassic magmas, which were originated from partial melting of metasomatic vein systems in the subcontinental lithospheric mantle of the North China Craton. These vein networks developed as a result of the reactions of fluids derived from subducted pelitic sediments on the downgoing Palaeo-Asian ocean floor with the enriched, subcontinental lithospheric mantle peridotites. Sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon dating has revealed a crystallization age of 415 Ma for the timing of the emplacement of the Gucheng pluton that marks the early stages of alkaline magmatism associated with the Andean-type continental margin evolution along the northern edge of the North China Craton facing the Palaeo-Asian Ocean.

The periodic dispersal and assembly of continental fragments has been an inherent feature of the continental crust. Based on the discovery of large-scale supercontinent cycle and the theory of plate tectonics, several supercontinents have been identified, such as Columbia/Nuna, Rodinia, Gondwana and Pangaea. Neoproterozoic magmatic events related to the break-up of Rodinia are globally well preserved. Although Neoproterozoic magmatic events were very weak in the North China Craton (NCC), they are crucial in reconstructing the geometries of the NCC and could facilitate the completion of the Neoproterozoic configuration of the supercontinent. In this study, c. 853–835 Ma magmatic rocks are identified in the western margin of the NCC. Precise zircon U–Pb age determination yields 206Pb/238U average ages of 835.5 ± 5.3 Ma (HL-39) and 853.7 ± 4.5 Ma (HL-30). In situ zircon Hf isotope compositions of the samples reveal that their parental magma was formed by the reworking of ancient crust evolved from Mesoproterozoic mantle. In summary, the discovery of Neoproterozoic magmatic rocks in the western margin of the NCC, and reported synchronous rocks in other parts of the NCC indicate that the NCC might be conjoined with the supercontinent Rodinia during the Neoproterozoic. This discovery is of significant help in unravelling the early Neoproterozoic history of the NCC and the evolution of the supercontinent Rodinia.

Geochronological, major and trace element, and Sr–Nd–Hf isotopic data are reported for the monzonitic rocks of the Fushan pluton in the Taihang Mountains, central North China Craton, in order to investigate their sources, petrogenesis and tectonic implications. Zircon U–Pb dating results reveal that the Fushan pluton was emplaced during the Early Cretaceous (∼126–124 Ma). The monzonites and quartz monzonites are mainly characterized by calc-alkaline and magnesian features and display light rare earth element (LREE) enrichment and flat heavy REE (HREE) patterns with slightly positive Eu anomalies. They have similar whole-rock initial 87Sr/86Sr ratios (0.70653–0.70819), εNd(t) values (−13.6 to −18.6) and zircon εHf(t) values (−21.8 to −17.3). The primary magma of the Fushan pluton was derived from the partial melting of a spinel-facies amphibole-bearing ancient enriched lithospheric mantle. The monzonitic rocks also have high Ba–Sr and low Y and Yb contents, with high Sr/Y and La/Yb ratios. These geochemical features of monzonitic rocks are not only inherited from the magma source but also significantly enhanced by crystal fractionation during magmatic evolution; e.g. hornblende fractionation increased the Ba–Sr concentrations and Sr/Y ratios. During the Early Cretaceous, the slab sinking and roll-back of the Palaeo-Pacific Plate could have created an ancient big mantle wedge beneath East Asia and induced a lithospheric extensional process in the central North China Craton within an intracontinental setting.

The Bengbu area in the southeastern North China Craton (NCC) consists predominantly of Archean–Palaeoproterozoic (gneissic) granitoids with minor supracrustal rocks (the Fengyang and Wuhe groups). This study presents new zircon laser ablation – inductively coupled plasma – mass spectrometry U–Pb and Lu–Hf isotopic data and trace-element contents for these granitoids, which improve understanding the Archean–Palaeoproterozoic crustal evolution of the NCC. Magmatic zircon U–Pb data reveal that zircons in the (gneissic) granitoids were generated by multi-stage events at 2.93, 2.73, 2.53–2.52 and 2.18–2.13 Ga. Metamorphic zircon U–Pb data obtained from these rocks show two distinct metamorphic ages of 2.49–2.52 and 1.84 Ga, suggesting that the Bengbu area experienced a regional metamorphic event at the end of the Neoarchean Era and encountered reworking by a tectonothermal event associated with the formation of the Palaeoproterozoic Jiao-Liao-Ji Belt. Trace-element compositions of magmatic zircons reveal the highest Ti concentrations (8.08±3.38 ppm) and growth temperatures (718±44 °C) for the zircons aged 2.13–2.17 Ga and an increase in zircon U/Yb ratios from 2.93 Ga (0.34±0.12) through 2.73 Ga (0.96±0.42) to 2.53 Ga (1.05±0.46), but an evident decrease at 2.17–2.13 Ga (0.61±0.40 ppm). Similar Palaeoarchean xenocrystic and detrital zircons with negative ɛHf(t) values, late Mesoarchean magmatic zircons with juvenile Hf isotopic features, early Neoarchean magmatic zircons with model ages of 2.9–3.0 Ga, and two regional metamorphic events at 2.52–2.48 and 1.88–1.80 Ga in the Bengbu and Jiaobei areas indicate a Palaeoarchean–Mesoarchean micro-continent entrained in the Jiao-Liao-Ji Belt at the southeastern NCC.

The North China Craton (NCC) is one of the classic examples of decratonization through extensive lithospheric destruction during Mesozoic time. Among the various pulses of magmatism associated with cratonic erosion are the rare mafic intrusions in the Yanshan Belt. Here we investigate the Shangzhuang layered intrusion belonging to this suite, which is characterized by compositional layering with troctolite, noritic gabbro and gabbro/gabbroic anorthosite/gabbrodiorite from the bottom to top. The different lithologies of this intrusion exhibit close field relationships, similar chemical patterns and overall identical Lu–Hf isotopes indicating a co-magmatic nature. The fine-grained gabbros occurring near the margin of the intrusion display U–Pb ages similar to those of the other rocks and are considered to represent the composition of the parent magma, characterized by Fe, Mg and Ti enrichment. The magma was sourced from low-degree partial melting of spinel lherzolite sub-continental lithospheric mantle, which had been enriched by crust–mantle interaction and metasomatic fluids derived from the Mongolian oceanic slab subduction beneath the NCC during Late Palaeozoic time. In addition, limited asthenospheric or deeper-mantle materials were also locally mixed with the enriched mantle as the final source component. Our zircon U–Pb data constrain the emplacement age of this intrusion as c. 128–123 Ma in Early Cretaceous time, and correlates with the regional extensional tectonics between c. 135 and 115 Ma in the eastern and central NCC. Mantle upwelling associated with this event resulted in the thermal and chemical erosion of the lithospheric mantle, and emplacement of the parent magma of this layered intrusion.

The Jurassic Linglong granites, intrusive into the North China Craton (NCC) in eastern China, provide a critical record of the first major episode of lithospheric-scale extension and magmatism in NE China during Mesozoic time. Our U–Pb zircon dating reveals that the Linglong granites were emplaced during 161–158 Ma, shortly after the inception of a shallow subduction of the Palaeo-Pacific plate beneath East Asia during Middle Jurassic time. These granites have high alkali contents (K2O + Na2O = 8–9 wt%), low MgO and Mg no. values and variable Cr–Ni abundances. Their relatively high Ba and Sr concentrations, relatively low heavy rare Earth element (HREE) and strongly fractionated REE patterns characterize them as high Ba–Sr granites. The negative whole-rock εNd(t) values ranging from −22.4 to −10.9 and wide-ranging zircon εHf(t) values of −39.1 to −1.5 suggest that magmas of the Linglong granites were produced by partial melting of a garnet-amphibolite-bearing lower crust of the Jiaobei Terrane and by re-melting of the Triassic ultrahigh-pressure (UHP) metamorphic rocks and alkaline suites of the Sulu Terrane. The occurrence in the granitic rocks of inherited zircons of the Neoarchaean, Palaeoproterozoic, Neoproterozoic, Palaeozoic and Triassic ages suggests that magmas of the Linglong granites interacted with the ancient crust in these terranes during their ascent. Asthenospheric upwelling, induced by the steepening and rapid rollback of the Palaeo-Pacific slab during Late Jurassic time, provided the heat source for the inferred lower crustal melting. Trench migration and thermal weakening of the crust caused extensional deformation and thinning in the eastern part of the NCC.

The link between lithosphere thinning and formation of world-class gold deposits is well established in the Jiaodong Peninsula within the eastern North China Craton (NCC). However, the timing of initiation and duration of the lithospheric thinning process as well as the depth of formation of the mineralization remain uncertain. Since these parameters are fundamental to formulate exploration strategies, in this study we perform fission track (FT) analysis on zircon and apatite grains in Late Mesozoic granitoid samples from the Jiaodong Peninsula and provide new constraints for the mode and duration of lithospheric evolution and mineralization depth. The zircon FT ages range from 64.3 to 90.9 Ma and those of apatite show a range of 32.8–50.9 Ma. The data collectively display age peaks at ~60–80 and ~30–50 Ma. Reverse modelling of the apatite FT results indicates rapid crustal uplift during ~30–80 Ma in the Jiaodong Peninsula. This period coincides with the timing of maximal sedimentation in the neighboring basins and voluminous basaltic eruptions in the eastern NCC. We suggest that the Jiaodong Peninsula has experienced two stages of crust uplift in the Late Cretaceous and Paleogene as a consequence of the continuing lithosphere thinning, together with the surrounding basins, forming the horst–graben system in the eastern NCC. The Late Mesozoic granitoids are the main wall rocks for gold deposits in Jiaodong, and thus the crust denudation history gathered from the FT data suggest that the gold mineralization formed at depths of c. 6–11 km.

The Archaean Jiaodong Terrane is located in the southern segment of the Palaeoproterozoic Jiao-Liao-Ji Belt, which separates the Eastern Block of the North China Craton into the Longgang and Langrim blocks. Controversy has long surrounded the issue of whether the Jiaodong Terrane is part of the North China Craton or an exotic terrane. This study presents new zircon U–Pb ages for the major lithologies of the Jiaodong Terrane, and the results indicate that the terrane underwent two main magmatic events at ~2.89 Ga and 2.62–2.56 Ga and two metamorphic events at ~2.5 Ga and 1.9–1.8 Ga. These ages are consistent with those of other metamorphic complexes in the Eastern Block, suggesting that the Jiaodong Terrane was part of the Neoarchaean basement of the Eastern Block, which was reworked at 1.9–1.8 Ga in association with the development of the Palaeoproterozoic Jiao-Liao-Ji Belt.

Amphibolites and metapelites exposed in the Zanhuang metamorphic complex situated in the south-middle section of the Trans-North China Orogen (TNCO) underwent upper-amphibolite-facies metamorphism and record clockwise P–T paths including retrograde isothermal decompression. High-resolution zircon U–Pb geochronological analyses indicate that the metamorphic peak occurred during ~ 1840–1860 Ma, which is in accordance with the ubiquitous metamorphic ages of ~ 1850 Ma retrieved by miscellaneous geochronologic methods throughout the metamorphic terranes of the northern TNCO, confirming that the south-middle section of the TNCO was involved in the amalgamation of the Eastern and Western Blocks of the North China Craton during the Palaeoproterozoic.

The most important crustal growth on Earth occurred at ~2.7 Ga, but the North China Craton (NCC) is characterized by prevalent development of ~2.5 Ga juvenile crust, with relatively rare records of ~2.7 Ga crustal growth. The Fuping Complex in the middle segment of the Trans-North China Orogen (TNCO) between the Eastern and Western blocks of the NCC is composed mainly of ~2.5 Ga Fuping tonalitic–trondhjemitic–granodioritic (TTG) gneisses and Longquanguan augen gneisses, ~2.1 Ga Nanying granitic gneisses and the Wanzi supracrustal rocks. Previous studies have suggested one major phase of crustal growth at ~2.5 Ga, possible intracrustal recycling at ~2.1 Ga and the presence of older rocks in the Fuping Complex, but there has been no record of ~2.7 Ga crustal growth. The Fuping TTG gneisses are dominated by stromatic migmatite, and new U–Pb dating of magmatic zircons from two stromatic migmatite samples yielded three different ages: (1) 2.75 Ga, which is the oldest age obtained from the Fuping TTG gneisses, (2) 2.54 Ga, which just falls in the published zircon U–Pb age range of 2.53 to 2.47 Ga for the Fuping TTG gneisses, and (3) 2.11 Ga, which is almost the same as the age of the Nanying granitic gneisses. Therefore, there are two generations of TTG gneisses in the Fuping Complex. Importantly, both of the 2.75 and 2.54 Ga zircons have the highest εHf(t) values, almost equal to the contemporaneous depleted mantle. This indicates high contributions of juvenile material to the two generations of TTG gneisses. In contrast, the 2.11 Ga zircons have apparently low εHf(t) values of −0.47 to +2.04, just falling in between 2.55 and 2.75 Ga continental crust values. This strongly suggests the reworking of the two generations of TTG gneisses at 2.1 Ga. Zircon U–Pb and Hf isotopes convincingly reveal two major phases of crustal growth in the Fuping Complex at ~2.7 and ~2.5 Ga, the same as in the northern and southern segments of the TNCO, and also confirm one major phase of intracrustal recycling at ~2.1 Ga, which may be responsible for the Nanying granitic gneisses.

Zircon U–Pb dating, whole-rock major oxide, trace element and Sr–Nd isotopic data are presented for the Late Mesozoic mafic intrusive rocks from Yiwulüshan of western Liaoning along the eastern segment of the Yanshan belt, North China craton, with two episodes of magmatism documented. Middle Jurassic hornblende-rich gabbros show enrichment of large ion lithophile elements and light REE, and prominent depletion in high field strength elements, and possess moderately enriched isotopic compositions with (87Sr/86Sr)i ranging from 0.7056 to 0.7065 and ɛNd(t) from −5.0 to −7.1. These features suggest that the gabbros were derived from an amphibole-bearing harzburgitic lithospheric mantle source metasomatized recently by slab-derived fluids. By contrast, Early Cretaceous mafic dykes are gabbroic dioritic to dioritic in composition, with comparable trace element characteristics to continental crust and depleted isotopic signatures ((87Sr/86Sr)i = 0.7048–0.7055, ɛNd(t) = 0 to −3.0). They probably originated from partial melting of a relatively fertile asthenospheric mantle in the spinel stability field, with subsequent lower crustal assimilation and fractional crystallization. These two contrasting mafic intrusive suites, together with multiple Mesozoic mafic volcanic rocks from western Liaoning, documented a localized lithospheric thinning process, mainly through prolonged hydro-weakening or melt–rock interaction and triggered by gravitational collapse, possibly within an evolved post-collisional to within-plate extensional regime.

Two types of metasedimentary rocks occur in the Trans-North China Orogen of the North China Craton. One type consists of highly metamorphosed supracrustal rocks with protoliths of mature cratonic shale, called khondalites, as found in the Lüliang Complex; rocks of the other type are also highly metamorphosed but less mature, as represented by the Wanzi supracrustal assemblage in the Fuping Complex. U–Pb isotopic data for detrital zircons from khondalites show a provenance dominated by 1.9–2.1 Ga Palaeoproterozoic rocks. These detrital zircons display a wide range of εHf values from −16.0 to +9.2 and give Hf isotopic model ages mostly around 2.3 Ga. The high positive εHf values approach those for the depleted mantle at 2.1 Ga, highlighting a juvenile crustal growth event in Palaeoproterozoic times. Hf isotopic data also imply that c. 2.6 Ga old crustal material was involved in the Palaeoproterozoic magmatic event. These data are similar to those for the khondalitic rocks from the interior of the Western Block of the North China Craton, suggesting a common provenance. In contrast, other metasedimentary rocks in the Trans-North China Orogen, such as the Wanzi supracrustal assemblage in the Fuping Complex, have a source region with both Palaeoproterozoic and Archaean rocks. Their detrital zircon Hf isotopic data indicate reworking of old crustal material and a lack of significant juvenile Palaeoproterozoic magmatic input. These rocks are similar to the coevally deposited meta-sedimentary rocks in the interior of the Eastern Block. We propose that the Lüliang khondalites were deposited on the eastern margin of the Western Block in a passive continental margin environment and were thrust eastward later during collision with the Eastern Block. Other metasedimentary rocks in the Trans-North China Orogen were deposited on the western margin of the Eastern Block in a continental arc environment. Our data support the eastward subduction model for the Palaeoproterozoic tectonic evolution of the North China Craton.

The Gangjia granite stock is a garnet-bearing muscovite leucogranitic body emplaced in Yiwulüshan in Western Liaoning Province at the eastern segment of the Yanshan orogenic belt, North China craton. The SHRIMP U–Pb zircon age is 153±5 Ma. The Gangjia granites are peraluminous with A/CNK of more than 1.14, and exhibit a tetrad effect in their REE distribution patterns, as well as non-charge-and-radius-controlled trace element behaviour. This is in contrast to the LREE-enriched patterns of the host Lüshan monzogranites. These geochemical characteristics, together with low Th/U ratios in zircon, suggest that the parental magmas for the Gangjia granites have experienced extensive magmatic differentiation, including interaction between residual melt and a coexisting high-temperature aqueous fluid. Their similar ϵNd(t), model ages, compatible age patterns and common volcanic arc signature in source materials between the Gangjia granites and the host Lüshan monzogranites indicate their comagmatic relationship. These unusual peraluminous leucogranites, coupled with the voluminous adakitic granites hosting them, represent typical post-orogenic magmatism developed under an intra-continental extensional tectonic regime. At the very end of the prolonged Jurassic magmatic evolution in Western Liaoning, extensive fractionation of most probably ferromagnesian phases and plagioclase from a calc-alkaline magma parental to the host Lüshan pluton, with overprint of the magmatic hydrothermal fluid, produced highly evolved peraluminous parental magmas for the Gangjia granites.