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The Zhangguangcai Range is located in the junction zone of the Palaeo‐Asian and Palaeo‐Pacific tectonic regimes; Mesozoic igneous rocks in this area are considered to have been formed in an active continental margin, which is related to the western subduction of the Palaeo‐Pacific Plate beneath the Eurasian continent. However, the nature of the mantle wedge and related melting mechanism remains unclear. This paper reports zircon U–Pb data, whole‐rock geochemistry, and zircon Lu–Hf isotope for a Late‐Triassic high‐Mg andesite in the southern part of the Zhangguangcai Range. Zircons from the andesite yield a concordant 206Pb/238U age of 218.6 ± 3.3 Ma, which is contemporary with the diorite in the study area. The Lengshan high‐Mg andesite is characterized by moderate SiO2 (57.30–60.15 wt.%), high Mg# (61–67), Al2O3 (15.05–17.35 wt.%), (La/Yb)N (16.9–22.4), and variable Na2O/K2O (1.06–1.59). Its insignificant Eu negative anomalies (Eu/Eu* = 0.88–0.99) and high Sr/Y (68.4–96.4) may prove the existence of garnet or amphibole in the residual melt, where feldspar is more or less absent. The andesite is enriched in Rb, Ba and depleted in Nb, Ta, Ti, and other high‐field‐strength elements, with Nb/Ta ratios of 14.6–17.2, U/Th ratios of 0.28–0.31. In combination with its depleted zircon Lu–Hf isotopic compositions (e.g., εHf(t) = −0.48 to +13.1), it is proposed that the high‐Mg andesite formed by hydrous melting of the mantle wedge, which was metasomatized by slab‐derived adakitic melts. The subsequent assimilation of ancient crust results in the formation of some zircons with negative Eu*/Eu anomalies (0.05–0.1) and εHf(t) values (−13.8 to −18.5), which is approved by the relative evolved whole‐rock Sr–Nd isotopic compositions. [ABSTRACT FROM AUTHOR]

This paper presents new zircon U–Pb ages and Hf isotope data, and whole‐rock major and trace element geochemical data of Permian igneous rocks from the eastern Songnen Massif (SM) and the western Jiamusi Massif (JM), NE China, to constrain their tectonic evolution. Zircon U–Pb dating indicates that Permian magmatism within the eastern SM can be subdivided into two stages: early Permian (ca. 293 Ma) and middle to late Permian (272–257 Ma). The early Permian igneous rocks comprise a bimodal association of rhyolites, basaltic andesites, and gabbros. The middle to late Permian igneous rocks are dominated by gabbro–diorites, monzodiorites, quartz diorites, monzonites, quartz monzonites, granodiorites, monzogranites, syenogranites, and alkali feldspar granites, along with minor bodies of A‐type quartz trachytes. The Permian felsic magmas originated mainly from partial melting of a relatively juvenile lower crust, whereas the coeval mafic rocks were probably derived from partial melting of a relatively depleted lithospheric mantle that was modified by fossil subduction‐related fluids. The igneous rock associations and their geochemical features, together with data from coeval sedimentary and volcanosedimentary successions, indicate that Permian magmatism within the eastern Songnen and western Jiamusi massifs formed in an extensional environment, similar to a back‐arc setting, related to westward subduction of a Palaeo‐oceanic plate beneath the eastern margin of the Jiamusi Massif. We find no evidence for double‐sided subduction of the Mudanjiang oceanic plate during the Permian. [ABSTRACT FROM AUTHOR]

The Central Asian Orogenic Belt (CAOB) is the largest accretionary orogenic belt in the world and its formation involved a complicated process of arc–continent collision. Large‐scale Mesozoic volcanic activity in the Great Xing'an Range (GXAR) in northeastern China, which constitutes part of the eastern CAOB, has received much recent research attention. However, the petrogenesis and formation mechanism of the late Mesozoic igneous rocks remain enigmatic. This paper investigates the geochronology, petrogenesis, and formation mechanism of late Mesozoic magmatic rocks in the Kelihe area of the GXAR based on zircon U–Pb dating, petrology, and geochemistry. Late Mesozoic magmatism in the Kelihe area occurred during the Late Jurassic (165–155 Ma) and Early Cretaceous (130–120 Ma). These igneous rocks generated by this magmatism are characterized by high SiO2 (69.97–75.49 wt%) and low MgO (0.11–0.68 wt%), Cr (10–30 ppm), Co (0.2–2.6 ppm), and Ni (0.5–1.6 ppm) contents. Trace elements show enrichment in Rb, Th, U, Zr, and K, and depletion in Ba, P, Nb, and Ti. These features indicate that the rocks were derived from partial melting of the crust. Furthermore, the rhyolites have high Na2O (5.02–5.44 wt%) and K2O (3.94–4.88 wt%) contents, similar to those of melts formed by the partial melting of basaltic crust. Combining the present results with the findings of previous studies, it is inferred that the Mesozoic igneous rocks formed in a post‐collisional extensional setting related to lithospheric thinning and asthenospheric upwelling after the closure of the Mongol–Okhotsk Ocean. [ABSTRACT FROM AUTHOR]

This paper reports in situ U–Pb ages and Hf isotopic data on detrital zircons from Palaeozoic strata in central‐eastern Jilin Province, NE China, with the aim of constraining the timing of final closure of the Paleo‐Asian Ocean and the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt (CAOB). Zircons from Middle to Late Permian Fanjiatun and Yangjiagou formations in central Jilin Province are characterized by four major groups of age populations (2.5–2.3 Ga, 1.9–1.7 Ga, 1.3–1.0 Ga, and Late Palaeozoic ages). The Paleo‐Mesoproterozoic and Cambrian zircons have positive εHf(t) values, suggesting that the source was mainly locally derived from the CAOB, whereas a lesser amount of Archean zircons with positive εHf(t) values, indicating that source from the North China Craton (NCC). The Phanerozoic zircons have both positive and negative εHf(t) values indicates that material from bidirectional provenances in the CAOB and the NCC. However, Late Permian Kaishantun Formation in eastern Jilin Province contain a single group of Phanerozoic zircons with positive εHf(t) values, distinct from known igneous zircons in the NCC, suggesting a local source. These observations, along with the results of previous studies on Middle–Late Permian igneous rocks in Jilin Province, indicate that the eastern segment of the Paleo‐Asian Ocean underwent the initial closure in central Jilin Province during the Middle Permian and the final closure in eastern Jilin Province in the Late Permian–Early Triassic. The detrital zircon geochronological data clearly record two stages of tectonic evolution and the scissor‐like closure model of the Paleo‐Asian Ocean in the eastern segment of the CAOB. [ABSTRACT FROM AUTHOR]

The Jiapigou gold ore belt is located in the northeastern corner of the wedge‐shaped North China Craton and is hosted by Neoarchean basement gneiss and amphibolite, along with late Palaeozoic and Mesozoic granitoids. In this paper, whole‐rock major and trace element geochemistry together with zircon U–Pb ages and Lu–Hf isotope compositions are reported for Late Permian to Triassic igneous rocks from the gold belt. The dominant population of zircons in all these rocks shows oscillatory growth zoning in CL images, and relatively high Th/U ratios (0.10–5.23) that are indicative of a magmatic origin. Zircon U–Pb data indicate that the igneous rocks formed during two major phases: ca. 252 Ma and ca. 230–213 Ma. Geochemically, the Late Permian (ca. 252 Ma) diorites are high‐K calc‐alkaline in composition and low total Fe2O3, MgO, and CaO contents, and represented by enrichment in LILEs relative to HFSEs and HREEs, all of which are indicative of a postcollision high‐K calc‐alkaline granite affinity. In contrast, the Late Triassic (ca. 230–213 Ma) igneous rocks are mainly quartz syenite porphyries, felsites, and granodiorites, and are variable medium‐ to high‐K calc‐alkaline series and exhibit a negative Eu anomaly with A‐type affinities, indicating an extensional environment. In addition, in situ Hf isotopic analyses of zircons from four dated samples reveal that they have εHf(t) values of −3.0 to +2.2, with two‐stage model (TDM2) ages range from 964 to 1,210 Ma, indicating that they probably originated from the partial melting of a dominantly Mesoproterozoic to Neoproterozoic crustal source. On the basis of the geochemical data and regional geological investigations, we further propose that the Jiapigou gold ore belt in the Late Permian was formed in a postcollisional tectonic setting, whereas an extensional tectonic setting in the Late Triassic that caused lithospheric thinning during a postorogenic event. [ABSTRACT FROM AUTHOR]

The Lesser Xing'an–Zhangguangcai Range is located in the eastern part of the Central Asian Orogenic Belt (CAOB). Early Mesozoic igneous rocks in this area can place constraints on the crustal growth mechanism in the Northeastern China. This paper reports a suite of Late Triassic high‐Mg diorites and mafic dikes from the southern Lesser Xing'an–Zhangguangcai Range. The mafic dikes have younger zircon U–Pb ages of 195 ± 2 Ma. They display intermediate SiO2 (50.58% to 58.20%) and high Na2O/K2O ratios of 1.90 to 3.20, low A/CNK ratios of 0.75 to 0.84, low (87Sr/86Sr)i ratios of 0.7045 to 0.7046, and high εNd(t) values of +3.1 to +3.5. Most zircons in the mafic dikes exhibit positive εHf(t) values from +8.6 to +16.0, with single‐stage Hf model ages ranging from 0.2 to 0.5 Ga in combination with their enrichment in LREE and LILEs and depletion in HFSEs. They are considered to be formed by melting of metasomatized subarc lithosphere mantle. The diorite and quartz diorite have older zircon U–Pb ages of 200 ± 3 and 202 ± 2 Ma, respectively. They have SiO2 = 54.45% to 61.18%, Al2O3 = 17.16% to 19.10%, TiO2 = 0.74% to 1.13%, and Mg# = 46.6 to 49.5, and they also display moderately depleted Sr–Nd (εNd(t) = +2.3 to +4.3) and zircon Lu–Hf (εHf(t) = +8.6 to +16.0) isotopic compositions. These features suggest that they were formed by melting of juvenile arc crust in active continental margin. Considering the occurrence of the contemporaneous and latter igneous rocks in the Zhangguangcai Range, we argue that the diorite, quartz diorite, and mafic dikes from the Lengshan area were also related to the westward subduction of Palaeo‐Pacific Plate (Izanagi Plate) beneath the Eurasian Plate. The strike‐like fault along the eastern margin of the Songneng–Zhuangguangcai Block may play an important role in the genesis of diorite melt. [ABSTRACT FROM AUTHOR]

Large‐scale magmatic activity and associated mineralization in South China are linked to the subduction of the palaeo‐Pacific Plate, although specific processes have remained controversial including the timing of subduction initiation and lithospheric extension. We present new geochemical data and zircon U–Pb and Lu–Hf isotope measurements on volcanic rocks, granites and mafic dikes from coastal south‐eastern China along the Eurasian continental margin. The biotite monzogranites show I–type granitoid affinity and fractional crystallization with zircon εHf(t) values ranging from −10.15 to +0.50, suggesting magma derivation from the melting of lower crust with the addition of juvenile crustal or mantle components. The biotite granites are typical of highly fractionated A‐type granites with εHf(t) values ranging from −3.63 to +1.35, indicating magma hybridization between anatectic granitic and mantle‐derived mafic magmas. The diabase dikes have zircon εHf(t) values ranging from −2.99 to +1.71, with high La/Nb and La/Ta ratios. This suggests derivation from partial melting of a lithospheric mantle metasomatized by fluid from a subducting–slab, with contributions of depleted asthenospheric mantle components. Our data, combined with those from previous studies, suggest that the shallow subduction of the palaeo–Pacific Plate beneath the Eurasian continent had begun by ca. ~170 Ma at least and the subduction orientation changed to oblique with respect to the continental margin. Steepening of the subduction angle likely caused a slab rollback during the Early Cretaceous, resulting in a tectonic transition from compression to extension in South China at ca. 145 Ma. [ABSTRACT FROM AUTHOR]

During the Late Ordovician, abundant siliceous rocks interlayered with K‐bentonites were widely distributed in the Wufeng Formation in the north‐western part of the Sichuan Basin, South China. In order to analyse the material provenance, redox condition, sedimentary environment, and their formation, here we present mineralogical and geochemical investigations on siliceous rocks samples collected from three sections. The presence of massive radiolarian tests, high Si/Si + Al + Fe + Ca ratios (0.87–0.99) and Al–Fe–Mn diagram plotting at nonhydrothermal area, reflects that the deposition of the siliceous rocks was simultaneous, effected by biogenic and terrigenous origin. The TiO2–Zr, La/Th–Hf, and La/Yb‐∑REE bivariate diagrams indicate that the provenance of Late Ordovician siliceous rocks was primarily from felsic igneous rocks. According to the palaeoredox indicators (V/(V + Ni), V/Cr, V/Sc, U/Th, and Ni/Co) and the size of framboidal pyrite, it is considered that the water column conditions of the Late Ordovician siliceous rocks were likely to be anoxic in all three sections. The application of parameters for relatively immobile elements allowed us to establish a continental margin for most samples from the three sections. Finally, we propose that the deposition of siliceous rocks was related to the accretion of the Cathaysia Block to the Yangtze Block. During the Late Ordovician, huge amounts of volcanic ash were released by intensified volcanic eruptions and fell into the ocean, triggering the proliferation of radiolarians. The abundant radiolarians and the persistent continental detritus constituted the major components of siliceous rocks in the Upper Yangtze Block. [ABSTRACT FROM AUTHOR]

The Lesser Xing'an Range in NE China is an important gold district. However, the age and genesis of Early Cretaceous magmatic rocks that are coeval with gold mineralization remain obscure. A suite of Early Cretaceous igneous rocks in a newly discovered gold deposit at Yongxin was conducted zircon U–Pb dating and Hf isotope and bulk‐rock geochemistry and Sr–Nd–Pb isotope analyses. A dacite of the Guanghua Formation and an andesite of the Longjiang Formation have zircon U–Pb ages of 111.7 ± 1.5 Ma and 119.7 ± 1.9 Ma, respectively. The dacite has zircon εHf(t) values of 5.4 to 12.0 and depleted bulk‐rock Sr–Nd–Pb isotopes ((87Sr/86Sr)i = 0.7049 to 0.7056, εNd(t) = 1.2 to 2.5, (206Pb/204Pb)i = 18.202 to 18.320). The andesite has zircon εHf(t) values of 5.6 to 13.6, (87Sr/86Sr)i of 0.7049 to 0.7051, εNd(t) of 1.0 to 1.6, and (206Pb/204Pb)i of 18.199 to 18.297. The ~120 Ma diorite porphyry and granite porphyry have zircon εHf(t) values of 3.7 to 10.0 and 3.6 to 10.2, respectively. These two units show large variations of 87Rb/86Sr ratios (<1) and similar Sr–Nd–Pb isotopes compositions. All rock units are enriched in light rare earth elements and large‐ion lithophile elements and depleted in high‐field‐strength elements. The formation of Yongxin Early Cretaceous igneous rocks was related to variable degrees of partial melting from Jurassic basalt in the lower crust with significant contribution from ancient continental materials. The low Sr/Y ratios (2–24) and negative correlations between Sr, Eu/Eu, and SiO2 indicate that magmas of the Early Cretaceous igneous rocks at Yongxin have low water content and thus have low potentiality for porphyry copper mineralization. [ABSTRACT FROM AUTHOR]

Early Paleoproterozoic rocks occur sporadically in the Sulu ultrahigh‐pressure (UHP) belt. The tectonic affinity and evolution of these rocks are still disputed. Two magmatic events (Early Paleoproterozoic and Neoproterozoic) and two metamorphic events (Late Paleoproterozoic and Triassic) were revealed by the zircon U–Pb ages and trace elements from the Weihai gneisses, which provide a key clue to understand the evolution of the Sulu orogen. The Early Paleoproterozoic zircons occur as residual zircons or zircon‐inherited cores in the two gneisses. They generally show oscillation zoning and enriched HREE patterns. The weighted mean age of the upper intercept age of these zircons is ~2.46 Ga, suggesting that the protolith of the ancient gneisses formed at ~2.46 Ga. The Late Paleoproterozoic zircons occur as metamorphic zircon core or mantle domains in the two gneisses and a quartzite. They generally show planar zoning or no zoning, with relative lower Th/U ratios. These zircons yield metamorphic ages of 1.8–1.84 Ga, which are consistent with the age of the Paleoproterozoic ultrahigh‐temperature metamorphism of the northern Sulu orogenic belt. The Neoproterozoic zircons occur as magmatic cores or mantles in the zircon grains of the two gneisses and their wall rocks. They show typical oscillatory zoning and enriched HREE patterns, yielding magmatic ages of ca. 740–787 Ma. The Neoproterozoic igneous rocks are the dominant basement rocks in the Sulu orogenic belt. Triassic UHP metamorphism has been well studied in the Sulu orogenic belt. Two Triassic age groups were also recognized here: 228–229 and 208 Ma, respectively. The Triassic zircons occur as metamorphic rims of the two ancient gneisses and their wall rocks. These two age ranges correspond to the time of subduction and exhumation of the the South China Craton (SCC) during the Triassic orogeny. This study provides solid evidence that the Weihai ancient gneisses have a strong affinity with the Yangtze Block. The protoliths of them are Paleoproterozoic (ca. 2.46 Ga) magmatic rocks. They were subsequently suffered from ca. 1.8‐ to 1.84‐Ga metamorphism, new crustal materials overgrowth during ca. 740‐ to 787‐Ma magmatism, and then experienced Triassic continental deep subduction and exhumation process to build the Sulu orogenic belt. [ABSTRACT FROM AUTHOR]

The Ulugqat Basin is located at the juncture of the Tarim Basin, the western Tianshan Orogen of the Central Asian Orogenic Belt, and the Pamir salient of the Tethys domain. A comprehensive provenance study using sedimentology, petrology, and detrital zircon U–Pb geochronology was carried out on the clastic rocks of the fifth member of the Lower Cretaceous Kezilesu Group from the Ulugqat Basin, aiming to better understand the nature of its relationships with the neighbouring tectonic units as well as the formation of sandstone‐hosted Zn–Pb mineralization. The fifth member consists of conglomerate, gravelly sandstone, sandstone, and mudstone interbeds, and is interpreted as alluvial fan–braid river–braid river delta sediments. The conglomerate and gravelly sandstone contain different kinds of lithic fragments, including phyllite, quartzite, chert, chalcedony, and some felsic igneous rocks, with low compositional maturities. The detrital zircon U–Pb ages of sandstone from the uppermost part of the fifth member range widely from 229.7 to 2,984.9 Ma, concentratedly distributed in five groups: 230–300, 390–480, 750–880, 1,600–2,200, and 2,300–3,000 Ma. The identified palaeocurrent directions, heavy mineral assemblages, specific provenance indicators, and distributions of detrital zircon U–Pb ages all indicate that these clastic rocks are probably sourced from the South Tianshan Orogen to the north, rather than the Pamir salient, probably involving the Proterozoic Aksu metamorphic rocks, Palaeozoic sedimentary rocks, Late Carboniferous–Early Permian alkali granite, and some mafic/ultramafic rocks of ophiolitic mélange. This interpretation is consistent with a late Early Cretaceous uplifting of the South Tianshan Orogen according to previous low‐temperature thermochronological data sets. The thick deposition of these Lower Cretaceous clastic rocks and associated uplifting of the South Tianshan Orogen are interpreted to be related to the coeval collision of the Karakoram–Lhasa Block with the southern Asian margin. [ABSTRACT FROM AUTHOR]

In this study, we present new U–Pb zircon ages and whole‐rock major and trace element data for the late Carboniferous–Middle Jurassic intrusive rocks in the Helong area, NE China. These data constrain the timing of tectonic transition from the Paleo‐Asian oceanic regime to the circum‐Pacific regime. U–Pb zircon dating indicates that the late Carboniferous–Middle Jurassic magmatic events in the Helong area can be subdivided into late Carboniferous, middle Permian, Early–Middle Triassic, Late Triassic, Early Jurassic, and early Middle Jurassic. The late Carboniferous granodiorites and middle Permian monzogranites belong to the calc‐alkaline series and have an affinity to I‐type granitoids, suggesting that they formed in a typical Andean‐type continental arc setting due to the southward subduction of the Paleo‐Asian oceanic plate beneath the NCC. The Middle Triassic granodiorites and monzogranites in the Helong area exhibit an affinity to adakitic rocks with their parental magma derived by the partial melting of thickened lower continental crust. The Late Triassic I‐type monzogranites and coeval ultramafic–mafic rocks constitute a bimodal igneous rock association, together with coeval A‐type granites and rhyolites, signifying an extensional environment. Combined with the absence of 240‐ to 225‐Ma sedimentation, the study area experienced a change from Early–Middle Triassic compression to Late Triassic extension related to the final closure of the Paleo‐Asian Ocean. The Early–early Middle Jurassic gabbros, diorites, granodiorites, and monzogranites are calc‐alkaline in nature and enriched in LREE and LILE but depleted in HREE and HFSE. Combined with the spatial variations in K contents of Early Jurassic igneous rocks in NE China from the continental margin to intracontinental region, and the presence of an Early Jurassic accretionary complex, we suggest that Early–early Middle Jurassic magmatism in the Helong area formed in an active continental margin setting related to the subduction of the Paleo‐Pacific Plate beneath Eurasia. We conclude that the tectonic transition from the Paleo‐Asian oceanic regime to the circum‐Pacific regime occurred in the Late Triassic–Early Jurassic. [ABSTRACT FROM AUTHOR]

The Jiamusi Block is an important tectonic unit in the Chinese segment of the CAOB. Its eastern margin became an active continental margin in the period of Late Carboniferous. However, the tectonic affinity of this section has not been resolved yet. The Early Permian andesites within the Erlongshan Formation in the eastern Jiamusi Block provide a critical record for the active continental margin setting. Precise LA‐ICP‐MS U–Pb zircon dating on four andesite samples gave ages of 280 ± 3 Ma, 282 ± 3 Ma, 286 ± 4, and 284 ± 2 Ma, respectively, defining an Early Permian age for the crystallization of the andesites. The andesites have medium‐K and calc‐alkaline compositions, with variable SiO2 (54.70–57.46 wt%), TiO2 (0.87–1.12 wt%), TFe2O3 (6.52–8.13 wt%), MgO (2.62–3.33 wt%), Al2O3 (15.96–17.83 wt%), Na2O (3.28–4.10 wt%), and K2O (1.16–1.95 wt%) contents. They are relatively enriched in LREEs ((La/Yb)N = 5.0–7.1) and LILEs (e.g., Ba, Th, Sr, and U), deleted in HREEs and HFSEs (e.g., Nb, Ta, Zr, and Y) and have weak or no Eu anomalies (Eu/Eu* = 0.87–1.02). These geochemical features indicate that the andesites within the Erlongshan Formation originated from an active continental margin setting, and their magma source was produced by partial melting of a mantle material that had been metasomatized by subduction‐related melts and subsequently underwent the removal of mafic minerals and accumulation of plagioclase. Integrated with previous studies on the igneous and sedimentary rocks, we thus propose that the Jiamusi Block was in an active continental margin setting in the period of the Late Carboniferous to Early Permian (310–280 Ma), and it is more likely related to the subduction of the Mongol‐Okhotsk Ocean. [ABSTRACT FROM AUTHOR]

The Sadaigoumen Mo deposit is a typical porphyry‐type deposit which is located in the northern margin of the North China Craton (NCC), China. Mineralization of the deposit mainly occurs as finely disseminated within the host granites. To get a better understanding of the ore‐forming process of the deposit and the genetic link between mineralization and host igneous rocks, we report LA‐ICP‐MS zircon U–Pb and whole‐rock major and trace elements data from the magmatic rocks which are exposed in the mining area. LA‐ICP‐MS U–Pb analyses yield weighed mean ages of 239.5 ± 0.58 Ma for alkali‐feldspar granites and 1872.8 ± 5.1 Ma for porphyritic granodiorite. The porphyritic granodiorite, which was previously considered to be part of the Hongqiyingzi Group, is redefined as Palaeoproterozoic highly fractionated I‐type granites: (1) They have high contents of SiO2 (69.57–72.21 wt.%) and Al2O3 (13.24–13.90 wt.%) and high Na2O + K2O (up to 7.1 wt.%) and FeOT/MgO values (6.7 to 7.7), and (2) significant depletion of Eu, Sr, Ba, P, and Ti elements; (3) compared with typical A‐type granites, they have lower Ga (around 20.5 ppm) and 10000 × Ga/Al values (around 2.8); the Triassic alkali‐feldspar granite samples also show highly fractionated I‐type geochemical signatures with high Na2O + K2O (8.40–8.50 wt.%), FeO*/MgO (12.67–13.49), and Ga/Al (2.58–2.81) ratios. The higher ∑REE values (>199.69 ppm) and depletions of Nb, Ta, and Ba make it different from typical A‐type granites. By comparative analysis of geochemical data, we believed that the ca. 1872.8 Ma porphyritic granodiorite formed in a tectonic environment resembling that of magmatic arc granites and the ca. 239.5 Ma alkali‐feldspar granite formed in syn‐collisional settings which is related to closure of Palaeo‐Asian Ocean. Our new data, combined with previous studies, allow us to speculate that the Triassic alkali‐feldspar granite is directly related to the Mo mineralization in this area. [ABSTRACT FROM AUTHOR]

Many data have been reported from the Early Palaeozoic subduction complex belt and accretionary arc to the south of the Solonker‐Xar Moron‐Changchun‐Yanji Suture (SXCYS) zone. However, as the suture is covered to the east by the Mesozoic–Cenozoic Songliao Basin, there have yet been no related reports about the Early Palaeozoic igneous rocks in this area. The authors discovered an Early Palaeozoic granitoid intrusion in the Fangjiatun area, northern Liaoning, and performed petrologic, geochemical, zircon U–Pb dating and Hf isotopic analyses on it. Zircon SHRIMP U–Pb dating results show that the intrusion formed at 437–432 Ma, that is, in the late stage of the Early Silurian. Petrogeochemical analysis indicates that the intrusion records 63.14%–66.45% SiO2, with Na2O/K2O ratios of 1.01–6.12 and magnesian index (Mg#) values of 32.42–40.82. The REEs show a certain degree of LREE/HREE fractionation and slightly lower ΣREE contents. The trace elements are relatively enriched in Rb, Ba, Th, K, and Sr (large‐ion lithophile elements [LILEs]) and depleted in Nb, Ta, P, and Ti (high‐field‐strength elements [HFSEs]), displaying continental magmatic arc characteristics. The rocks have high Sr mass fractions, low Y and Yb mass fractions, and high Sr/Y ratios, which are consistent with the geochemical signatures of typical adakites. Zircon Hf isotopic analyses indicate that their εHf(t) values range from 0.29–6.56, reflecting the relatively depleted signatures of the source area. Based on its occurrence location and emplacement time, the intrusion is interpreted to have been produced by tectonic thermal events during the subduction of the Palaeo‐Asian oceanic crust beneath the northern margin of the North China Craton (NCC), thus reflecting the existence of an Early Palaeozoic continental marginal accretionary arc in the eastern segment of the NCC along the south of the SXCYS and provide new evidence for the tectonic evolution of the northern margin of the NCC in the Early Palaeozoic. [ABSTRACT FROM AUTHOR]

We present zircon U–Pb and Hf isotopic and whole‐rock geochemical data for late Paleozoic igneous rocks in the central Great Xing'an Range, northeast China, to constrain the late Paleozoic amalgamation history of the united Xing'an–Erguna and Songnen–Zhangguangcai Range massifs. Based on zircon U–Pb dating, we ascertain three main stages of magmatic events: Late Devonian (381–364 Ma), early Carboniferous (360–341 Ma), and late early Carboniferous–early Permian (328–271 Ma). Late Devonian rhyolites originated from partial melting of Meso‐proterozoic accreted lower crust. The crust‐derived rhyolites and coeval mantle‐derived basalts constitute a bimodal volcanic association in the west. Early Carboniferous igneous rocks include syenogranites, monzogranites, gabbro diorites, and gabbros. The granitoids are derived from partial melting of Meso‐proterozoic accreted lower crust. The gabbros and gabbro diorites show the spatial variation in zircon εHf(t) values (−0.53 to +0.84 in the east and +12.3 to +13.5 in the west), which imply that they were mainly derived from metasomatized mantle wedge and asthenosphere mantle, respectively. These characteristics indicate that northwest‐towards high‐angle subduction of the Paleo‐Asian Ocean plate beneath the united Xing'an–Erguna Massif induced arc magmatism in the east and back‐arc magmatism (similar to back‐arc rift) in the west during the Late Devonian to early Carboniferous. Late early Carboniferous–early Permian sub‐alkaline and alkaline igneous rocks are characterized by multiple sources, such as the depleted mantle, juvenile lower crust, and thickening lower crust. Their temporal variations in geochemical characteristics imply that the central Great Xing'an Range was situated under a transitional setting from syn‐collisional to post‐collisional during the late early Carboniferous to early Permian. Using the combined insight from lithofacies palaeogeography and regional magmatisms, we suggest amalgamation of the united Xing'an–Erguna and Songnen–Zhangguangcai Range massifs occurred during the late early Carboniferous to late Carboniferous. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]