The Jinying gold deposit is located in southern Jilin Province in northeast China and is representative of the large Early Cretaceous gold deposits in this area. To better understand ore genesis of this deposit, a multi-isotope integrated analysis of U–Pb–Rb–Sr–He–Ar–S has been carried out. Laser ablation inductively coupled plasma–mass spectrometry (LA–ICP–MS) dating of zircons from the granodiorite porphyry and dioritic porphyrite in the study area yields ages of 172.1 ± 1.2 Ma and 122.5 ± 0.8 Ma, suggesting that corresponding intrusion occurred in the Middle Jurassic and the Early Cretaceous. Rb–Sr dating of the pyrite yields an isochron age of 120 ± 3 Ma, suggesting that gold mineralization occurred in the Early Cretaceous. The fluid inclusions in pyrite yield 3He/4He ratios clustered within a small range from 0.08 to 0.13 Ra, 40Ar/36Ar ratios between 331.6 and 351.3, and mantle He in the range of 1.0–1.6%, indicating that the ore-forming fluids originated from a mixed crustal and mantle source. The in situ S isotopic values of pyrite vary between + 0.1 ‰ and + 2.8 ‰, suggesting that the ore-related sulphur came from the deep magmatic source. Combined with the geological history of the study area, it can be concluded that the gold mineralization was possibly related to the extensional setting associated with the rollback of the Palaeo-Pacific Plate.

The Harihada–Chegendalai ophiolitic mélange, which is located between the Bainaimiao arc and the North China Craton, holds significant clues regarding the tectonic setting of the southern margin of the Central Asian Orogenic Belt. The ophiolitic mélange is mainly composed of gabbroic and serpentinized ultramafic rocks. Here, zircon U–Pb dating, in situ zircon Hf isotopic, whole-rock geochemical and in situ mineral chemical data from the ophiolitic mélange are reported. The zircons in the gabbroic rocks yielded concordia U–Pb ages of 450–448 Ma and exhibited slightly positive ϵHf(t) values (0.87–4.34). The geochemical characteristics of the gabbroic rocks indicate that they were generated from a mantle wedge metasomatized by subduction-derived melts from sediments with continental crust contamination, in a fore-arc tectonic setting. These rocks also experienced the accumulation of plagioclase. The geochemical characteristics of the ultramafic rocks and their Cr-spinels indicate that they may constitute part of residual mantle that has experienced a high degree of partial melting and has interacted with fluids/melts released from the subducted slab in the same fore-arc tectonic setting. The ophiolitic mélange may therefore have formed in this fore-arc tectonic setting, resulting from the northward subduction of the South Bainaimiao Ocean beneath the Bainaimiao arc during Late Ordovician time, prior to the collision between the Bainaimiao arc and the North China Craton during the Silurian to Carboniferous periods.

The medium-sized Ergu Fe–Zn polymetallic skarn deposit is located in the central Lesser Xing’an Range, NE China. The ore bodies are mainly hosted in the contact zone between granodiorite intrusions and lower Cambrian dolomitic crystalline limestones or skarns. To reveal the magmatic influence on the mineralization, resource potential and metallogenic geodynamic process of this deposit, a systematic study of the geology, petrology, zircon U–Pb dating, element geochemistry, amphibole geochemistry and Sr–Nd–Pb–Hf isotopes of the Ergu deposit intrusives was conducted. The results show the following: (1) The major rock types in the mine area are medium-grained granodiorite and porphyritic granite, and the rock related to mineralization is medium-grained granodiorite. Zircon U–Pb dating suggests that the granodiorite and porphyritic granite formed at 181.9–183.8 Ma and 182.7 Ma, respectively. Thus, an Early Jurassic magmatic event led to the formation of the Ergu deposit. (2) The granodiorite and porphyritic granite are high-K calc-alkaline I-type granites that formed by comagmatic evolution with varying degrees of fractional crystallization and were likely derived from partial melting of the lower crust. The Ergu deposit occurred in an active continental-margin tectonic setting. (3) The high water content (5.69 wt % H2O), high oxygen fugacity (ΔFMQ = +1.75 to +1.82) and intermediate-plutonic emplacement (3.13 km) of the granodioritic magma are key factors in the formation of the Ergu deposit. The porphyry granite is characterized by high water content (>4 wt % H2O), reduced oxygen fugacity (ΔFMQ = −0.47) and shallow emplacement (<3 km).

Situated between the South China Block and the Simao Block, the Ailaoshan Belt is a significant component of the Jinshajiang–Ailaoshan tectonic-magmatic-metallogenic belt of southwestern China. The formation of the Ailaoshan Belt is closely related to the evolution of the Palaeo-Tethys Ocean. In this study, we constrain ages of sedimentation in the Jinchang Au–Ni deposit in the Ailaoshan Belt, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb ages of the youngest populations of detrital zircons separated from a chert layer and two uncomfortably overlying meta-sandstones. The combined data of the meta-sandstone samples from the Yiwanshui Formation yielded a concordant age of 250.8 ± 0.6 Ma (mean square weighted deviation (MSWD), 2.8; n = 26). The chert sample from the Jinchangyan Formation yielded a concordant age of 347.0 ± 1.5 Ma (MSWD, 2.8; n = 16). Detrital zircons from the meta-sandstone are characterized by low rare earth element contents (∑REE) and low Y, and high U and U/Yb ratio, suggesting a continental crustal origin. Zircons in the meta-sandstones were derived mainly from pre-collision subduction zone magmatic rocks related to the closure of the Palaeo-Tethys Ocean. In contrast, detrital zircons from the chert contain relatively high ∑REE and Y, and low U and U/Yb ratio, suggesting an oceanic crust origin. Zircons in the chert bed were derived mainly from ophiolites related to seafloor spreading in a branch of the Palaeo-Tethys Ocean.

Most skarns are found near the pluton or in lithologies containing at least some limestone. However, recent research has shown that neither a pluton nor limestone is necessarily required to form a skarn deposit. The newly discovered Bagenheigeqier Pb–Zn skarn deposit is located in NE China. The skarn and Pb–Zn orebodies occur in volcanic lithologies of the Baiyin’gaolao Formation and are controlled by NE–SW-trending faults. The nearest pluton is a granite porphyry, at a distance of 20–250 m from the orebodies. Five paragenetic stages at Bagenheigeqier are recognized: (I) skarn; (II) oxide; (III) early sulphide; (IV) late sulphide; and (V) late quartz–calcite. The fluid inclusions from stages II to V homogenized at temperatures of 402–452, 360–408, 274–319 and 167–212°C, respectively. The hydrogen and oxygen isotope compositions (δ18OH2O, –12.4‰ to +9.3‰; δDH2O, –156.5‰ to –99.1‰) indicate that the ore-fluids were primarily of magmatic origin, with the proportion of meteoric water increasing during the progression of ore formation. Sulphur isotope values (δ34SVCDT, 1.4–5.5‰), lead isotope values (206Pb/204Pb, 18.184–18.717; 207Pb/204Pb, 15.520–15.875; 208Pb/204Pb, 37.991–38.379) and the initial 187Os/188Os ratios of the pyrite (0.307 ± 0.06) suggest that the ore metals were derived from the granite porphyry and Baiyin’gaolao Formation. Re–Os dating of pyrite intergrown with galena and sphalerite yielded a well-constrained isochron age of 151.2 ± 4.7 Ma, which is coeval with the laser ablation – inductively coupled plasma – mass spectrometry zircon U–Pb age of 154 ± 1 Ma for the granite porphyry. The deposit was therefore formed during Late Jurassic time.

We present detailed petrography, geochemistry and zircon U–Pb–Hf isotopes of the Mante Aobao granite porphyry in East Ujimqin Banner, Inner Mongolia, with the aim of determining its age and petrogenesis, important for understanding the early Palaeozoic tectonic evolution of the Xing’an–Mongolian Orogenic Belt. The Mante Aobao granite porphyry consists of plagioclase, quartz and minor biotite, but without amphibole. Zircon U–Pb analyses yield ages of 450 ± 1 Ma and 445 ± 2 Ma for the granite porphyry, indicating that it formed during Late Ordovician time. The granite porphyry is metaluminous to slightly peraluminous (aluminous saturation index A/CNK = 0.98–1.11) with high SiO2, K2O and Na2O concentrations and differentiation index (DI = 85–90). Chondrite-normalized rare earth element (REE) patterns display enrichment of light REEs (LREEs) with high ratios of (La/Yb)N and negative Eu anomalies. In the mantle-normalized multi-element variation diagrams, all samples are characterized by depletions of high-field-strength elements (HFSEs; Nb, Ta and Ti) and enrichments of large-ion lithophiles (LILEs; Rb, Th, U and K). These geochemical features indicate that the granite porphyry is a highly fractionated I-type granite and formed in a subduction-related setting. Zircon grains have positive εHf(t) values of +9.2 to +11.2, and TDM2(Hf) ages of 691–821 Ma, suggesting that the granite porphyry was generated by partial melting of Neoproterozoic juvenile crust with involvement of fractional crystallization during magmatic evolution. It is likely that underplating of mantle-derived magmas during Late Ordovician time provided the necessary heat to partially melt this juvenile crust. Combined with the regional geological data, we infer that the Mante Aobao granite porphyry was emplaced in an active continental margin setting that was probably related to the northwards subduction of the Paleo-Asian Plate beneath the South Mongolian Terrane along the Sonid Zuoqi–Xilinhot axis.

The East Kunlun Orogen (EKO) is the NW part of the Central China Orogenic Belt, which records the evolutionary history of the Proto- and Palaeo-Tethys Oceans from the Cambrian to the Triassic. An Early Palaeozoic eclogite belt has been recognized in recent years, which extends discontinuously for ∼500 km as three eclogite-bearing terranes. In this study, we report an integrated study of zircon grains from mica-schists accompanying the eclogites, in terms of mineral inclusions, U–Pb age systematics and P–T conditions. The presence of coesite is identified, as inclusions within the metamorphic domain of zircons, which provides unambiguous evidence for subducted terrigenous clastic rocks of the Proto-Tethys Ocean exhumed from coesite-forming depths. U–Pb dating of the metamorphic zircons yields a concordia age of 426.5 ± 0.88 Ma, which is likely to be the time of ultrahigh-pressure metamorphism in the Kehete terrane. P–T calculations suggest that metapelite may have experienced a clockwise P–T path with peak P/T conditions of 685 ± 41 °C and >28 kbar, and equilibrated at 482–566 °C and 5.6–8.9 kbar during subsequent exhumation. The high-pressure – ultrahigh-pressure (HP-UHP) metamorphic belt within the EKO may have formed by collision between the Qaidam Block and the South Kunlun Block, as a consequence of the closure of the Proto-Tethys Ocean.

Multistage magmatic thermal events occurred in the Yardoi Dome and contain important information on the tectonomagmatic processes. The dome has played a crucial role in understanding the collisional evolution of the Tethyan Himalayan. We present new geochronological and geochemical data for muscovite-granite exposed in the Liemai area, Eastern Tethyan Himalayan Belt. Liemai muscovite-granite is strongly peraluminous, with A/CNK values characterized by evolved geochemical composition with high contents of SiO2-enriched large-ion lithophile elements, and is depleted of high-field-strength elements. These geochemical features indicate that granites possibly derived from partial melting of metasedimentary rocks and plagioclase fractional crystallization probably played a critical role in production of peraluminous granitic melts. Zircon U–Pb dating from muscovite-granite yielded ages of approximately 48.5 ± 1.1 Ma, representing its crystallization ages. This age is the oldest age of Tethyan Himalayan leucogranite from the Yardoi Dome and adjacent areas. However, the inherited zircon cores have ages of 135.7–3339.2 Ma. The εHf(t) values of all zircons vary from –6.4 to –2.3 and have varying Hf-isotope crustal model ages of 731–839 Ma. The geochemical and isotopic compositions indicate that magma of the Liemai granite can most likely be interpreted as products of the break-off related to thermal perturbation along the break-off window associated with the subduction of Neo-Tethyan slab. These magmas were derived mainly from the anatexis of ancient crustal materials under contraction and thickening conditions due to subduction of the Indian continent beneath southeastern Tibet.

In this paper we present new petrological and whole-rock geochemical data for the Palaeoproterozoic metasedimentary rocks in the upper part of the Ji'an Group within the Jiao–Liao–Ji Belt, China, as well as zircon U–Pb age dates and in situ Lu–Hf isotope data. The new data improve our understanding of the original nature of the metasedimentary rocks, further providing insights into their tectonic setting and the evolutionary history of the northern segment of the Jiao–Liao–Ji Belt. The zircons can be divided into two groups, viz., one of magmatic origin and the other of metamorphic origin. Zircon U–Pb dating gave mean or statistical peak ages for the magmatic zircons at 2035, 2082, 2178, 2343–2421, 2451–2545, 2643–2814 and 2923–3446 Ma, and mean peak ages for the metamorphic zircons at 1855 and 1912 Ma, which indicate a maximum depositional age of 2.03 Ga and two-stage metamorphic events at c. 1.91 and 1.85 Ga for the metasedimentary rocks. Geochemical data show that (1) the protoliths of these rocks were mainly sandstones, greywackes and claystones, together with some shales; (2) the main sources of the sedimentary material were Palaeoproterozoic granites and acid volcanic rocks, with minor contributions from Archaean granitic rocks; and (3) the sediments were deposited in an active continental margin setting. Moreover, along the northeastern margin of the Eastern Block of the North China Craton there is evidence of ancient crustal materials as old as 3.76 Ga, and multiple crustal growth events at 3.23–3.05, 2.80–2.65, 2.54–2.45 and 2.28–2.08 Ga.

The Datong pluton, the largest early Palaeozoic granitoid in the Western Kunlun Orogenic Belt (WKOB) in NW China, is a typical appinite-granite complex. It consists of diorites, quartz diorites, monzodiorites, quartz monzodiorites, monzonites, quartz monzonites, syenites, granodiorites and monzogranites. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating yielded crystallization ages of 459 ± 3 Ma for the quartz monzonites and 452 ± 5 Ma for the monzogranites (Late Ordovician). The rocks possess a wide range of SiO2 (56.0–73.4 wt %), MgO (0.17–4.55 wt %) and Mg no. (25–60), with high K2O (2.83–5.29 wt %) contents, exhibiting high-K calc-alkaline to shoshonitic traits. They are characterized by enrichments in large-ion lithophile elements (LILEs) and light rare Earth elements (LREEs), as well as depletions in high-field-strength elements (HFSEs). The rocks have initial 87Sr/86Sr ratios of 0.7086–0.7185, negative εNd(t) values of –3.72 to –1.79 and εHf(t) values vary from –1.6 to +4.7. These features are modelled to show that they were most likely derived from an enriched lithospheric mantle source and that fractional crystallization with minor crustal contamination was involved in their petrogenetic process. Considering the distribution and chronology of the Palaeozoic intrusions – such as Kegang, Bulong, Qiukesu, Yierba, North Kudi, Dongbake, Buya, Ayilixi and Warengzilafu granitoid plutons with ages of c. 420–530 Ma – in conjunction with the Palaeozoic metamorphic overprinting in the WKOB, we propose a divergent double-subduction model to explain the destruction of the Proto-Tethys Ocean and suggest that the Datong pluton was likely emplaced in a post-collisional setting following the termination of subduction in response to slab break-off.

A Neoproterozoic granite (Western Huhetaoergai granite) from the Northern Alxa region, southern Central Asia Orogenic Belt (CAOB) is first recognized by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb zircon dating (889±8 Ma). It is a highly fractionated potassium-rich calc-alkaline pluton with low εNd(t) (−2.6 to −1.1) and high (87Sr/86Sr)t (0.727305–0.735626), and is probably derived from a mantle source and assimilated crustal rocks with very high 87Sr/86Sr. Regional geology implies that it may reflect the existence of a microcontinent, and the formation of the Western Huhetaoergai granite is related to the assembly of Rodinia.

Cretaceous granites are widespread in the North Dabie orogen, Central China, but their emplacement sequence and mechanism are poorly known. The Tiantangzhai Complex in the North Dabie Complex is the largest Cretaceous granitic suite consisting of six individual intrusions. In this study, zircon U–Pb ages are used to constrain the crystallization and protolith ages of these intrusions. The Shigujian granite is a syn-tectonic intrusion with an age of 141 Ma. This granite was emplaced under a compressional regime. Oscillatory rims of zircons have yielded two peaks at 137±1 Ma and 125±1 Ma. The 137±1 Ma peak represents the beginning of orogenic extension and tectonic collapse, whereas the 125±1 Ma peak represents widespread granitic magmatism. Zircon cores have yielded concordant ages between 812 and 804 Ma, which indicate a crystallization age for the protolith. The Tiantangzhai granites show relatively high Sr contents and high La/Yb and Sr/Y ratios. The Shigujian granite has positive Eu anomalies resulting from partial melting of a plagioclase-rich source in an over-thickened crust. Correspondingly, in situ Lu–Hf analyses from zircons yield high negative εHf(t) values from −24.8 to −26.6, with two-stage Hf model ages from 2748±34 to 2864±40 Ma, suggesting that the magmas were dominantly derived from partial melting of middle to lower crustal rocks. The Dabie orogen underwent pervasive NW–SE extension at the beginning of the early Cretaceous associated with subduction of the Palaeo-Pacific plate beneath eastern China.