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Whether the Yangtze Block was involved in the global late Mesoproterozoic orogeny remains contentious. The Mesoproterozoic Huodiya Group exposed in the Hannan‐Micangshan Massif on the northwestern margin of the Yangtze Block could provide sufficient evidence to further clarify the regional tectonic affinity. However, quantitative insights into the depositional age, provenance and basin tectonic setting of the Huodiya Group still lack comprehensively constraining. This study presents a combined analysis of zircon U–Pb dating for meta‐sedimentary rocks of the Shangliang Formation of the upper Huodiya Group and intruded gabbroic dykes. Intergraded dating results constrain the late Mesoproterozoic maximum depositional age at ca. 1050 Ma. Ca. 900 Ma formation age for the intruded gabbroic dyke, plus the minimum formation age of the overlying Xixiang Group at ca. 950 Ma, further suggests its deposition should be prior to ca. 950–900 Ma. Concordant detrital zircon ages define pronounced age clusters of ca. 2229–1741 and 2950–2388 Ma and few age populations of ca. 3232–3082 and 1069–1033 Ma, consistent with the tectonothermal events in proximal domains at the northwestern and northern Yangtze Block. Detrital zircon age distribution patterns and cumulative curves, coupled with the stable carbonate platform and shallow‐marine facies sedimentation, suggest a passive continental margin setting for the Huodiya Group on the Yangtze Block margin at the late Mesoproterozoic. Comparative insights into the contemporaneous passive continental margin from north to southwest argue against the existence of a late Mesoproterozoic orogeny along the exterior periphery of the Yangtze Block. [ABSTRACT FROM AUTHOR]

The ductile shear deformation of Precambrian basement rocks in Wuyishan provides a crucial perspective on intraplate orogeny in the South China Block (SCB). This study focuses on the Longquan‐Badu ductile shear zone in southeastern Zhejiang, employing field observations, thin section analysis, quartz electron backscatter diffraction (EBSD), zircon U–Pb dating and 40Ar/39Ar geochronology. Two distinct phases of deformation, referred to as D1 and D2, have been identified. D1 is primarily characterized by a WNW–ESE striking foliation within a NE‐plunging lineation, indicating top‐to‐SSW shearing. The paragneiss within the Badu complex that experienced D1 deformation has been dated to 247–239 Ma through zircon U–Pb analysis, corresponding to the prevalent high‐pressure metamorphic age in the region. This correlation suggests that the D1 deformation event coincided with crustal thickening during the Early Triassic. D2 deformation exhibits folds, foliation, S‐C fabrics and mylonitic microstructures and is mainly characterized by striking NNE–SSW with steeply dip, demonstrating a dominant dextral strike–slip component. Quartz c‐axis orientations in mylonitic rocks indicate deformation temperatures between 350°C and 550°C with asymmetric girdle patterns suggesting simultaneous basal and prism slip. The plateau ages of muscovite from mylonitic rocks obtained through 40Ar/39Ar dating are approximately ~228 Ma implying that the D2 deformation occurred under retrograde amphibolite to greenschist facies metamorphic conditions during Middle Triassic. Collectively these data along with regional geological evidence signify two distinct intracontinental orogenic processes occurring in eastern SCB. Considering Early Mesozoic tectonothermal events in Cathaysia Block, it can be inferred that intraplate orogeny in Wuyishan resulted from plate‐margin collisions between SCB and peripheral plates following scissors closure of Palaeo‐Tethys from east to west. [ABSTRACT FROM AUTHOR]

The Feidong Complex, located on the northeastern margin of the Yangtze Craton, exposes Precambrian basement rocks and is the subject of debate regarding its tectonic affinity. In this study, we conducted in situ U–Pb dating and Hf isotope analyses of zircons from basement rocks within the Feidong Complex. The results reveal crystallisation ages of ca. 2.45, 2.0 and 0.8 Ga for the granitic gneiss, amphibole biotite plagiogneiss and mylonitised monzonitic granite, respectively. The basement rocks with ages of ca. 2.45 and 2.0 Ga exhibit negative zircon εHf(t) values (−10.48 to −0.13) and older two‐stage model ages (TDM2 = 2974 to 3296 Ma). We compared the zircon U–Pb ages and Hf isotopic characteristics of the basement rocks from the Feidong Complex with those of the southern margin of the North China Craton and the northern margin of the Yangtze Craton. Additionally, we also compared the metamorphic grades of rocks between the Feidong Complex and Susong Complex of the Dabie orogenic belt. We found that the Feidong Complex and the northern margin of Yangtze Craton share comparable zircon U–Pb ages and Hf isotopic characteristics. However, the metamorphic grades of the Feidong Complex were distinct from those of the Susong Complex. In particular, the basement rocks with an age of ca. 2.45 Ga formed within a subduction setting; those with an age of ca. 2.0 Ga formed during the subduction and collision associated with the assembly of the Columbia supercontinent; and those with an age of ca. 0.8 Ga experienced extensional processes before the breakup of the Rodinia supercontinent. [ABSTRACT FROM AUTHOR]

The Tongbai complex plays an important role in the understanding of the tectonic evolution of the Tongbai‐Dabie orogenic belt. By detailed structural analysis, new zircon U–Pb dating, zircon Lu–Hf analysis and whole‐rock elements for the rocks in the Tongbai complex and the wrapped shear zones, we suggested that the Tongbai complex was derived from the partial melting of the basement of Yangtze Block and experienced a uniform orogen‐parallel extension with a top‐to‐NW shearing at 142–133 Ma. The migmatites yield a migmatization age of 116 ± 2 Ma and are identical to the metamorphic age of 115–111 Ma from the L and LS tectonites in the Tongbai complex. The late Early Cretaceous migmatization may give rise to the severance of the uniform top‐to‐NW shear zone and lead to an antiform folding of the Tongbai complex. The similar deformation and migmatization of the complexes in both the Tongbai and Dabie orogenic belts suggest that the Tongbai‐Dabie orogenic belt is likely to have a similar tectonic transformation from orogen‐parallel to orogen‐perpendicular extension in the Early Cretaceous, namely a uniform orogen‐parallel extension of the ductile lithosphere during the early Early Cretaceous and a widespread migmatization during the late Early Cretaceous. [ABSTRACT FROM AUTHOR]

The northeastern periphery of the Qaidam Basin is a crucial region for comprehending the northeastward growth of the Tibetan Plateau, as it documents Late Cenozoic crustal deformation that elucidates the plateau's growth process. In this study, we reconstruct three stages of crustal deformation in the northeastern periphery of the Qaidam Basin during the Late Cenozoic based on interpretation of growth strata from five seismic profiles, structural mapping of the typical superimposed folds and detailed detrital zircon analysis within the study area. (1) During the Early Miocene to Late Miocene period (23–8.6 Ma), there was NW–SE extensional deformation in the northeast margin of the Qaidam Basin, which exerted control over the deposition of the Youshashan Formation. (2) The NW–SE shortening occurred during the Late Miocene period (8.6–8.1 Ma), subsequent to the deposition of the Youshashan Formation and preceding the deposition of the Shizigou Formation, resulting in a parallel unconformity between these two geological units. (3) The intense shortening of the NE–SW direction occurred during the Late Miocene and Pliocene epochs (8.1–2.5 Ma). The timing of this deformation aligns with the sedimentary age of the Shizigou Formation, suggesting that the initial deformation age may represent the onset of NE extrusion from the Tibetan Plateau towards the northeast margin of the Qaidam Basin. The present study not only delineates a Late Cenozoic structural dome resulting from two‐stage crustal shortening in the northeastern periphery of the Tibetan Plateau, but also provides a crucial evidence for reconstructing the Late Cenozoic intracontinental deformation process in this region. [ABSTRACT FROM AUTHOR]

The North Qinling Orogenic Belt (NQB) records the pivotal geological information for understanding the Palaeozoic evolution of the Qinling Orogenic Belt (QOB). Previous studies mainly focused on the subduction–collision process along the Shangdan suture zone before the Early Devonian. However, as the significant interim period between the Early Palaeozoic and Mesozoic orogeny, the Late Palaeozoic tectonic evolution of the NQB remains poorly understood. Fortunately, the Carboniferous magmatic rocks discovered this time provide substantial geological evidence for revealing the Late Palaeozoic tectonic history of the Qinling Orogenic Belt. This paper will provide a detailed analysis of zircon U–Pb ages, geochemical characteristics and Sr‐Nd‐Hf isotopic compositions of Carboniferous rocks. The Carboniferous magmatic rocks are categorized as highly differentiated S‐type granite and monzodiorite, formed at 350 ± 2.4 Ma and 353 ± 5.2 Ma, respectively. The granite shows weak peraluminous (A/CNK = 1.02–1.11) and shoshonite nature. Based on the isotopic composition and trace element characteristics, we propose that the Qinling Group paragneiss is the primary source of the Carboniferous granite. Monzodiorite is characterized by enriched LREEs and LILEs (Ba, K and Pb), depleted HFSEs (Th, Nb, Ta and Ti) and enriched Sr‐Nd isotopic composition. Monzodiorite magma source region consists of continental crustal material and lithospheric metasomatized mantle. Carboniferous magmatic rocks are the product of an extensional tectonic setting, which indicates the NQB tectonic regimes transition from compression to extension during the Carboniferous. [ABSTRACT FROM AUTHOR]

The Jiamusi Block is a crucial geological unit joining multiple tectonic regimes, including the Late Palaeozoic Palaeo‐Asian Ocean and the superposition of the Early Mesozoic Palaeo‐Pacific tectonic domain. However, the duration of the Palaeo‐Pacific Plate subduction beneath the Jiamusi Block has long been controversial. In this paper, we focus on clastic rocks from the Nanshuangyashan and Yunshan formations on the east margin of the Jiamusi Block and use the modal analysis of sandstones and detrital zircon U–Pb dating to trace the subduction history of the Palaeo‐Pacific Plate. Our analysis results suggest that the two groups of samples are characterized by a high content of monocrystalline quartz and a low content of lithic and feldspar, indicating that the sedimentary provenances were stable continental blocks and magmatic arcs. The detrital zircon ages of the Nanshuangyashan Formation have a major peak at ca. 245 Ma and two secondary peaks at ca. 470 and 228 Ma, respectively. The Yunshan Formation has a major peak at ca. 494 Ma and a secondary peak at ca. 265 Ma. The provenances of the Nanshuangyashan Formation were attributed to the Jiamusi Block, Khanka Block, and a Late Triassic magmatic arc. Similarly, the provenances of the Yunshan Formation were attributed to the Jiamusi and Khanka blocks. Detrital zircon analysis results show that the eastern margin of the Jiamusi Block was in the same back‐arc basin settings in the Late Triassic and the Late Jurassic. Thus, we propose that the eastern margin of the Jiamusi Block had been affected by the Palaeo‐Pacific Plate subduction in the Late Triassic and had continued to the Late Jurassic. [ABSTRACT FROM AUTHOR]

The Geo‐chronology of the Mesozoic sequences from the northern Ordos Basin provides an excellent window for understanding the source‐to‐sink analysis and tectonic settings. In this study, nine groups of detrital zircon U–Pb ages from the Middle Triassic to Lower Cretaceous strata of the northern Ordos Basin are presented. Three dominant age groups are revealed through the kernal density estimation: ca. 2,300 ~ 2,500 Ma (Siderian), ca. 2,050 ~ 1,800 Ma (Orosirian), and ca. 358.9 ~ 298.9 Ma (Carboniferous). Significant differences are distinguished according to multidimensional scaling analysis and cumulative distribution function. The Middle Triassic sample is the closest to the Yin Mts and the upper Triassic and lower Jurassic samples have significant similarities with the Jining area. The samples YA‐1 and ZL‐1 from the Middle Jurassic sequences are the closest to the Daqing Mts (DQS) and Wula Mts (WLS), respectively. The sample ZL‐1 is the second closest to the DQS. The sample YJ‐1 from the Lower Cretaceous sequences has apparent affinities with multiple resources, including the DQS, WLS and samples EM‐1 and AD‐1, while the sample LH‐1 only resembles the sample YA‐1. Overall, the northern Ordos Basin experienced three stages of transformations in the source areas: (a) Southward migration during the Middle Triassic and the Early Jurassic; (b) Westward migration during the Early Jurassic and latest Middle Jurassic; (c) Southward migration during the latest Middle Jurassic, and multiple resources and recycled sediments for the Cretaceous sequences. The transition to the North China Craton's (NCC) extensional tectonic setting was closely related to the transformation from the Palaeo‐Asian Ocean's closure to the Palaeo‐Pacific Plate's subduction during the Early Jurassic. The multiple resources and recycled resources for the Lower Cretaceous sequences were related to the destruction of the NCC. [ABSTRACT FROM AUTHOR]

The Kalatag area contains many intrusive rocks of Late Ordovician to Permian age and hosts polymetallic deposits that are associated with magmatism. It is a key area for revealing the nature and genesis of the Palaeozoic rocks in East Tianshan. The intrusive rocks of different periods preserve useful information regarding the tectonomagmatic history of the Kalatag area. Zircon U–Pb geochronological, Hf isotopic, Sr–Nd isotopic, and whole‐rock geochemical analyses are reported for the intrusions from the Meiling ore district, Yudai ore district, and Kalatag pluton to reveal their petrogenesis and geodynamic setting. The LA–ICP–MS zircon U–Pb analyses suggest that the quartz diorite from the Kalatag pluton formed at 420–432 Ma, and the quartz diorite porphyry from the Yudai ore district formed at 436–439 Ma. The zircons from the quartz diorite and quartz diorite porphyry mainly yield high εHf(t) values (12.2–16.2) and very young Hf model ages (TDM = 0.41–0.56 Ga; TDMC = 0.49–0.56 Ga), which are consistent with a depleted mantle origin. The geochemical characteristics of the granites and quartz diorites from the Kalatag pluton and diorite porphyry from the Meiling ore district exhibit typical subduction‐related features such as enrichment in LILEs and LREEs and depletion in HFSEs. These diorites have moderate Mg# (30–47), positive εNd(t) values (4.2–5.6), and young Nd model ages (0.62–0.83 Ga), which are consistent with a depleted mantle origin that is accompanied by limited crustal assimilation. Based on the regional geology and geochemical evidence and previous studies, the Ordovician–Carboniferous rocks from the Kalatag area are considered to have formed in an island‐arc setting and were probably formed by a subduction event. [ABSTRACT FROM AUTHOR]

The Lohit Plutonic Complex (LPC) represents Trans‐Himalayan magmatic rocks in the easternmost sector of the Himalayan Orogen. It is divided into leucogranite‐granodiorite‐diorite dominant suite in the NE and the gabbro‐diorite‐granodiorite‐granite–trondhjemite suite in the SE by the Walong Thrust. U–Pb geochronological analyses of euhedral zircon grains from different magmatic phases of LPC reveal episodic magmatism. Zircon U–Pb age of 153.4 ± 1.4 Ma of a garnetiferous granite gneiss suggest that the crustal sourced magmatism was active in Arunachal Trans‐Himalaya during the late Jurassic. U–Pb ages of subduction induced magmatic rocks of LPC range between 117 ± 0.6 Ma and 49.5 ± 0.3 Ma. A significant contribution in crustal recycling during the Oligocene–Miocene is evident from crustally derived leucogranites having U–Pb ages ranging from 35.6 ± 0.3 Ma to 30 ± 0.3 Ma. A comparison of the crystallization ages of the Western Trans‐Himalayan units with those of eastern Trans‐Himalayan units reveals an earlier onset of Tethyan arc magmatism in the eastern sector. The most prominent phase in the eastern sector is during the Late Cretaceous while western and central sector show major activity during the Palaeocene–Eocene. [ABSTRACT FROM AUTHOR]

The Early Pennsylvanian land plant community is characterized by widespread forests consisting of lycopsids, ferns, and seeds fern in swampy wetlands. The contemporaneous palynological assemblages are mainly composed of spores of Lycospora spp., Densosporites spp., and Laevigatosporites spp. and monosaccate prepollen of Florinites spp. Taeniate bisaccate pollen appeared for the first time during the Early Pennsylvanian but never prevailed in the coeval palynological assemblages. Here, we report a taeniate bisaccate pollen‐dominated palynological assemblage from the Jiamuhe Formation of Well Ke 85 in the Zhongguai Uplift, northwestern Junggar Basin, Xinjiang. Nineteen miospore species belonging to 14 genera were identified from the assemblage. Based on their relative abundance, one assemblage is nominated informally as Calamospora breviradiata–Lunatisporites tersus (BT) assemblage. SIMS U–Pb geochronological analysis of zircons from two volcanic ash beds from the basal and upper parts of the formation yields weighted mean 206Pb/238U dates of 316.3 ± 2.2 Ma (MSWD = 1.2, n = 19) and 316.5 ± 2.8 Ma (MSWD = 0.85, n = 20) in an ascending order. A Bashkirian age is thus assigned to the BT assemblage. Our combined palynological and geochronological investigations reveal an early stage of the rise of conifers in the Kazakhstan Plate and offer a rare glimpse into the Early Pennsylvanian land vegetation in the subtropical area at the northern hemisphere. [ABSTRACT FROM AUTHOR]

A study of heavy mineral assemblages, rutile compositions, and detrital zircon age populations in Namurian to Westphalian sandstones in North Wales, deposited in the southwestern part of the Pennine Basin of the United Kingdom, has revealed considerable complexity in their provenance history. The Pendleian to Marsdenian Cefn‐y‐fedw Sandstone Formation, which is known to have been derived from the Wales–Brabant Massif (WBM) to the south on the basis of palaeocurrent and petrographic information, has a heavy mineral assemblage characteristic of this southerly provenance, and includes Late Neoproterozoic zircons apparently of local WBM origin. However, the formation is dominated by zircons that were most probably recycled from sandstones of northern origin from the Caledonian Belt that had been previously deposited over the massif during Late Devonian times, and, as such, has a comparable history to the sedimentologically‐equivalent Morridge Formation of the English Midlands. Heavy mineral analysis shows that sandstones in the Brigantian Minera Formation and Yeadonian part of the Bowland Shale Formation are of similar southern provenance. The Yeadonian Gwespyr Sandstone, previously interpreted as having a northern origin, similar to the time‐equivalent Rough Rock, has variations in heavy mineral analysis and zircon spectrum that suggest a complex provenance history and includes sand bodies with northern, western, and southern origins. [ABSTRACT FROM AUTHOR]

As a record of oceanic subduction, an accretionary complex plays a key role in the reconstruction of plate tectonic history. The Kekesentao ophiolitic mélange between the Chinese Altai orogen to the north and the Kazakhstan collage to the south played an important role in the subduction–accretion of the Chinese Altai in the Palaeozoic. This article provides new structural field relations, and petrographic, geochemical, and geochronologic data for the Kekesentao ophiolitic mélange, and detrital zircon analyses of turbidites that are imbricated with the mélange. The Kekesentao mélange consists of ultramafic rocks, meta‐gabbros, pillow basalts, cherts, and imbricated trench turbidites, tuffaceous sandstones and quartz schists (ocean plate stratigraphy). The mélange shows a 'block in matrix' structure in the field, and the general imbricated dip of the thrust system is to the N‐NE, indicating southward accretion. Pillow basalts and meta‐gabbros have a typical N‐MORB geochemical signature, and the U–Pb zircon age of a meta‐gabbro, interpreted as the age of pre‐subduction oceanic crust, is Early Devonian (399–393 Ma). The upper time limit of accretion of the mélange is constrained by a Late Devonian (361 Ma) intrusive granitic pluton. Detrital zircon ages of surrounding turbidites range from 369 to 3,114 Ma, which is typical of magmatic 540–460 Ma zircons from the Chinese Altai, suggesting that the Chinese Altai arc was the source of zircons in the mélange. The Kekesentao ophiolite was accreted to the accretionary complex before the Late Devonian. Our analysis of structures, ocean plate stratigraphy, and zircon isotopic provenance of the Kekesentao ophiolitic mélange and turbidites provides a robust conclusion that southward growth of the accretionary complex in the Kekesentao area of the Chinese Altai was semi‐continuous from the Early Palaeozoic to Devonian. [ABSTRACT FROM AUTHOR]

The South Altyn Block (SAB), located along the southern margin of the Altyn Tagh in Qaidam Basin, has a significant relationship with the tectonics of the Qaidam Basin basement. This study presents the petrological features, geochemical compositions, and zircon U–Pb and Hf isotope data of four granitic plutons from the eastern segment of the SAB to constrain the petrogenesis and tectonic setting of this region during the Palaeozoic. Basing on previous U–Pb dating results, the zircon U–Pb analysis in this study suggests that Palaeozoic magmatic events can be subdivided into four episodes: Late Cambrian (approximately 502 Ma), Late Ordovician (approximately 444 Ma), Early Devonian, and Middle Permian (approximately 271 Ma). The Palaeozoic granitoids were derived mainly from Neoproterozoic juvenile crustal components, with minor palaeoproterozoic ancient materials. The S‐ and I‐type granitoids in Late Cambrian indicate a compressional tectonic environment with respect to subduction, and A‐type granitoids suggest post‐collision regime. The Late Ordovician granodiorites of A‐type imply typical magmatism within a post‐collision extensional setting. Ascribing to the subduction of Palaeo‐Tethys Ocean during the Devonian, S‐type granites were emplaced in the Early Devonian accompanied with the crust thickening. The Middle Permian magmatic events include a series of S‐type granitoids, demonstrating the setting of oceanic subduction along with the closure of the Palaeo‐Tethys Ocean. [ABSTRACT FROM AUTHOR]

The Sanshilipu monzogranites is located in the northern margin of the South Qinling Block, with an outcrop of about 10 km2, and as an intrusion into Palaeozoic Danfeng ophiolitic mélange. The samples consist mainly of plagioclase, K‐feldspar, quartz, biotite, and minor titanite, apatite, magnetite, with contents of SiO2 (61.73–68.49%), Al2O3 (14.58–16.61%), K2O + Na2O (5.79–8.87%), MgO (1.07–2.91%), and low TiO2 (0.55–0.83%), similar to those of I‐type granite. They also show high concentrations of LREE, Pb, and Sr, slightly negative Eu, but low HREE, Nb, Ta, and Y. High Sr and Sr/Y, low Y characteristics are similar to those of adakite. High precision LA‐ICP‐MS U–Pb dating and trace element analysis of zircon in the Sanshilipu granite yielded a concordant age of 205 ± 1 Ma. This age is apparently younger than the closure age of the Mian‐Lue Ocean (242–221 Ma). We propose that the Sanshilipu monzogranites formed by magma mixing of thickened lower crust and limited mantle‐derived mafic magma during post‐collision of the South China and North China blocks. [ABSTRACT FROM AUTHOR]

To detect the exhumation history of the southwestern South China Block (SCB), we performed fission track (FT) analysis on zircon and apatite grains in granitoid and sedimentary samples. From east to west, the study area includes the Yunkai Massif, Lingshan granitic belt, Shiwandashan Basin, and eastern margin of the Youjiang Basin. The granite sample of the Yunkai Massif has two peaks of 75 and 92 Ma for zircon FT dating. The Lingshan granitic belt samples yield zircon FT central ages from 135 to 132 Ma. The Permian bauxite samples of the Youjiang Basin yield zircon FT central ages from 109 to 93 Ma and display age peaks at ~97–93 Ma. The Yunkai Massif granite sample has two peaks at 74 and 104 Ma for apatite FT dating, while the Lingshan granitic belt sample has two peaks at 81 and 111 Ma. The cooling paths of the Yunkai Massif sample started with an Early Cretaceous (~120–100 Ma) cooling event that brought the granitoids into the apatite partial annealing zone (PAZ). Through comparative studies, we suggest that the southwestern SCB underwent three periods of crustal uplift during ~135–132, ~111–92, and ~ 81–74 Ma, respectively, which is consistent with the regional stratigraphic unconformity and crustal extension. Only the Yunkai Massif and Lingshan granitic belt were uplifted during ~135–132 Ma. During ~111–92 Ma, the southwestern SCB experienced crustal uplift, and the basal conglomerate began to deposit in the Shiwandashan Basin. Late Cretaceous uplifted occurred during ~81–74 Ma, and the Yunkai Massif was uplifted throughout the Cretaceous. From 97 to 92 Ma, the Permian bauxite deposits in the Youjiang Basin were uplifted, which provided the basis of the later transformation to Quaternary bauxite. [ABSTRACT FROM AUTHOR]

As an important part of the Central Asian Orogenic Belt (CAOB), Chinese western Tianshan contains voluminous Late Palaeozoic volcanic rocks. Here, we present geochronological, geochemical, and in situ Lu–Hf isotopic data from the Atengtao sanukitic high‐Mg andesites (HMAs) of the western Yili Block. LA‐ICP‐MS zircon U–Pb analyses indicate that the Atengtao high‐Mg andesites were generated in the Early Carboniferous (346 ± 2 Ma). All the studied rock samples are characterized by high MgO (3.30–5.45 wt.%), SiO2 (53.25–60.10 wt.%), Cr (90.3–157 ppm), and Ni (31.0–46.7 ppm) contents, with geochemical characteristics analogous to those of sanukitoids of the Setouchi Volcanic Belt (SVB), SW Japan, and Bieluagaxi area, West Junggar. The Atengtao sanukitic HMAs are enriched in LILE and LREE but depleted in HFSE, similar to those of typical arc‐related magmatic rocks. They are also characterized by high Nb (11.4–15.8 ppm) concentrations, high Th/La (0.3) and Th/Yb (2.6–4.0) ratios, and varying zircon εHf(t) values (−2.3 to +4.3). These features are suggested to result from the partial melting of a relatively enriched mantle wedge metasomatized by subducting oceanic slab‐derived sediments. Considering the occurrence of sanukitic HMAs, combined with the contemporaneous special rock assemblages (such as slab‐derived adakite, Nb‐enrich basalt, A‐type granite/rhyolite, and bimodal volcanic rocks) found in the western part of Yili Block, we propose that the generation of the Carboniferous sanukitic HMAs in Atengtao Mountain were most likely related to the slab break‐off following the southern Tianshan Ocean slab northward subduction beneath the Yili–Central Tianshan Block. This mechanism not only produces intense magmatism with compositional diversity but also gives rise to a local extension in the western part of Yili Block. The slab break‐off model may play an important role in the crustal growth of the CAOB in Phanerozoic time. [ABSTRACT FROM AUTHOR]

The Salem Mafic–Ultramafic Complex occurs within the northern part of Cauvery Suture Zone (CSZ), Southern Granulite Terrane (SGT), India. The complex occurs as semicircular to elongated linear body with a thick mantle section and comparatively well‐developed crustal section comprising different lithological units, also referred to as the Chalk Hills of Salem. The major rock types in the complex comprise ultramafic cumulates of dunite, peridotite, wherlite, pyroxenite, and hornblendite, mafic and felsic intrusions of gabbros and amphibolites, and quartzo–feldspathic alkaline rocks together with several ultrapotassic dykes. Geochemical studies of amphibolites from this complex indicate tholeiitic parent magma with enrichment of LIL elements (Rb, Ba, Th, and Sr) and are relatively more enriched than N‐MORB as compared with arc‐related rocks. The enrichment of LIL elements over the HFS elements and with distinct Nb, Ta, and Ti depletion relative to other HFS elements suggest the involvement of subduction‐related components in the depleted mantle source and that the magmatism occurred in an oceanic convergent realm. The mineral chemistry of dunite and peridotite shows high content of forsterite (86.9–92.2) in olivine and high Cr# value (80.85–98.73) for spinel. The tectonic discrimination plots of spinel and olivine mineral chemistry together with clinopyroxene chemistry of amphibolites reveal arc signature typical of Alaskan type of complex. The U–Pb zircon analysis of quartz monzonite intrusion within the hornblendite from the complex yielded a weighted mean age of 819 ± 2.4 Ma, suggesting that the complex formed during the Neoproterozoic and can be correlated to the Alaskan‐type complexes described from the Arabian–Nubian Shield. [ABSTRACT FROM AUTHOR]

Xishan coalfield, Shanxi, is located in the northwest of the Qinshui Basin, central North China. It is notable for its varieties of coal rank ranging from high volatile bituminous coals to anthracite as well as having abundant coalbed methane resources. Zircon fission track (ZFT) analyses were carried out on the zircons in 2 Upper Carboniferous and 5 Lower‐Middle Permian sandstones, and vitrinite reflectance of Late Carboniferous and Early Permian coals were measured to determine the timing of thermal events and maximum paleo‐temperatures, which were responsible for coal maturation and coalbed methane generation. Maximum paleo‐temperatures calculated from vitrinite reflectance values reached to about 232 and 223 °C in Late Carboniferous and Early Permian coals, respectively, and the estimated paleo‐temperature gradient was 11.84 °C/100 m, representing an intensive abnormal thermal event. Results of the ZFT dating indicated that 5 samples failed the χ2‐test and 2 samples passed the test. The decomposition results of the 5 samples divided their age populations into 3 periods: (a) older ages (537, 584, and 802 Ma) than sandstones ages, (b) close to or slightly older than their depositional ages (289, 301, and 331 Ma), and (c) younger than the depositional ages (181–215). The 2 samples that passed χ2‐test yield the central ages of 168 ± 7 Ma and 190 ± 8 Ma, respectively, younger than the deposition age. The close to or older ages than the sandstones depositional ages represent the tectonothermal events occurring in their source areas; the younger ages indicate the existence of the postdepositional tectonothermal event. The agreement of the partly annealing temperature zone (210–300 °C) of zircon fission tracks with the calculated maximum paleo‐temperatures from vitrinite reflectance suggests a Late Triassic‐Early Jurassic abnormal thermal event with the formation time of the present coal rank being 181–215 Ma, rather than a unique intrusion at 95–135 Ma on the western margin of coalfield as previously believed. Combined with other ZFT ages regionally, this abnormal event also occurred in the southern as well as the northern parts of the Qinshui Basin. The Late Triassic‐Early Jurassic intensive extension in the North China Craton is the geodynamic setting of this tectonothermal event. [ABSTRACT FROM AUTHOR]

We conducted zircon U–Pb dating and geochemical analyses for the Qianjinchang (QJC) pluton in the Xi Ujimqi, Northeast China, with an aim to determine their ages, petrogenesis, and sources. The QJC pluton consists of coarse/medium‐grained biotite monzogranite in the core and fine‐grained biotite granodiorite in the rim; those rocks intrude into quartz diorite but are intruded by minor intrusive phases, including small biotite syenogranite, diorite bodies, late diorite, granodiorite, granite, and pegmatite dykes. Our new laser ablation inductively coupled plasma mass spectrometry zircon U–Pb data indicate that the QJC composite pluton composed of 2 phases of magmatic activities, with the ages of 301~313 Ma for the quartz diorite, 283 ± 1 Ma for the biotite granodiorite, 280 ± 1 Ma for the biotite syenogranite, and 280 ± 2 Ma for the diorite dyke. Hf isotopic analyses for the quartz diorite sample show εHf (t) = 3.75 to 11.72, with 2‐stage Hf model age (TDM2) ranging 568–1,078 Ma. The biotite syenogranite sample also shows a depleted εHf (t) = 4.47 to 8.71, with TDM2 ranging 745–1,015 Ma, suggesting the major involvement of juvenile crustal components. The various εHf values of the QJC pluton indicate a hybrid magma source of juvenile material with old crustal component, and the TDM2 values increase from the Carboniferous to Permian, which suggests an increasing proportion of old continental material during this period. Petrological and geochemical characteristics of the biotite granodiorite and biotite monzogranite samples suggest that they are S‐type granites and derived from partial melting of the clay‐poor, plagioclase‐rich psammitic source, produced at low‐medium pressure. The biotite syenogranite sample belongs to alkaline and shoshonitic series and probably formed by a hybridization process between basaltic magma and old continental components. Combined with previous studies on the contemporaneous magma‐tectonic activities in the Xilinhot microcontinent, we suggest that the QJC pluton formed in a postcollisional setting. [ABSTRACT FROM AUTHOR]

The Heihe–Nenjiang–Hegenshan suture zone has long been accepted as the major tectonic boundary between the Xing'an and Songliao blocks and extends through the Great Xing'an Range in NE China, but its location of the northern segment between the Moguqi and Nenjiang areas and its timing remain unclear. We address these issues by presenting zircon LA‐ICP‐MS U–Pb ages, Lu‐Hf isotopes, bulk‐rock major, and trace elemental data for mylonitized rhyolites collected from the Moergenhe Formation in the Nenjiang area and for gabbros of the Moguqi area, respectively. The mylonitized rhyolites, which display an arc‐related geochemical affinity with enrichment in Th and U, and depletion of Nb, Ta, and Ti, and gently right‐tilted rare earth element (REE) patterns (light REE [LREE]/heavy REE [HREE] =4.53–7.60), as well as the εHf (t) values (+6.4 to +11.8) of analyzed zircons, indicate an origin by partial melting of potentially young lower continental crust of a subducting slab. The zircon LA‐ICP‐MS U–Pb data show the formation age of the mylonitized rhyolites is 352.4 Ma. The analyzed gabbros with an emplacement age of 352.6 Ma have high concentrations of Th and U, slightly enriched LREE patterns and relative low LREE/HREE ratios (4.3 to 4.6). These features, together with their high positive εHf (t) values (+7.7 to +15.2), suggest that they were likely derived from the partial melting of a depleted mantle source that was metasomatized by subduction‐related fluids. Combined with the geochemical features of the coeval igneous rocks from the northern Great Xing'an Range, these results reveal that the existence of an early Carboniferous NE‐trending magmatic arc (ca. 350–330 Ma), extending along the west of the Heihe–Nenjiang–Hegenshan suture zone, gives more constraints on the amalgamation of the Xing'an and Songliao blocks along the Nenjiang–Moguqi areas and indicates that the amalgamation should have terminated by at least the end of the early Carboniferous. [ABSTRACT FROM AUTHOR]

The Keketale is the largest Pb–Zn deposit in the volcano‐sedimentary Maizi Basin of the South Altay Orogenic Belt (AOB), Northwest China. The stratabound orebodies are hosted in a suite of meta‐sedimentary rocks intercalated with volcanic rocks of the Lower Devonian Kangbutiebao Formation. The massive and banded ores representing the main mineralization stage are relatively well‐preserved in the ore district. This paper reports systematic geochronological results including the zircon laser ablation–multiple collector–inductively coupled plasma–mass spectrometry (LA‐MC‐ICP‐MS) U–Pb analyses on two meta‐felsic volcanic rocks from the Kangbutiebao Formation and Rb–Sr isotope dating on seven sphalerite samples from the main mineralization stage, together with some sulphur isotopic data to constrain the mineralization age and the genesis of the deposit. Rb–Sr isotope dating yield an isochron age of 398.2 ± 3.3 Ma generally synchronous with the zircon (LA‐MC‐ICP‐MS) U–Pb analyses of a meta‐rhyolite and a meta‐dacite from the strata (410.5 ± 1.3 Ma and 394.8 ± 1.9 Ma, respectively). The δ34S values of seven pyrite samples in the main massive and banded ores vary from −12.4‰ to −6.2‰, indicating that the main ore‐forming sulphur of the deposit was derived from bacterial reduction of seawater sulphate. By integrating the field, chronological, and isotopic evidences, we conclude that the Keketale Pb–Zn deposit is a VMS‐type deposit. Combining our results with the isotopic geochronology in the South AOB, we argue that the South AOB has undergone three mineralization episodes: the syndepositional mineralization (412–387 Ma), the subvolcanic hydrothermal‐related mineralization (382–379 Ma), and the epigenetic mineralization that is genetically linked to regional metamorphism and deformation (260–204 Ma). The Keketale Pb–Zn deposit is a product of the Devonian seafloor hydrothermal exhalation system in the South AOB. [ABSTRACT FROM AUTHOR]

Adakite‐like volcanic rocks in the Moguqi area of the central Great Xing'an Range of NE China consist of trachyandesites and trachydacites. These rocks yield LA–ICP–MS U–Pb zircon ages of 229.5–232.6 Ma. These adakite‐like rocks are high in Sr (459–1960 ppm) and MgO (1.2–4.3%), low in Y (11.4–23.70 ppm) and Yb (0.88–2.07 ppm), and have high Sr/Y ratios (37.17–146.31) and high Mg# values (0.43–0.58). These characteristics are similar to those of rocks derived from slab melting. However, the existence of Early Triassic stable continental sedimentary rocks of the Laolongtou Formation does not favour this mode of formation. The zircon εHf(t) values of the samples range from +8.09 to +13.29, indicating the primary magmas were generated by partial melting of juvenile crust. Analysis of geophysical data, combined with the previously published history of the Hegenshan–Heihe Suture in this region and the southward subduction of Mongol–Okhotsk oceanic plate, suggests that the Late Triassic adakite‐like volcanic rocks in the Xing'an Massif formed from the partial melting of delaminated thickened crust in an extensional setting. This occurred after orogenesis involving the Xing'an Massif and the Songnen Massif and was influenced by southward subduction of the Mongol–Okhotsk oceanic plate. [ABSTRACT FROM AUTHOR]

The tectonic affinity of the Ama Drime Massif in central Himalaya remains a subject of debate. We provide evidences of the metamorphic conditions and new geochronological data for orthogneiss and paragneiss in the Riwu area, eastern side of Ama Drime Massif. The peak P-T conditions for garnet gneiss is 13-14 kbar and 750-765 °C using phase equilibria modelling. The zircon U-Pb dating results reveal that the orthogneiss has a crystallization age of 1,848 ± 12 Ma and zircon rims age of 1,767 ± 18 Ma. Three major age peaks characterize all detrital zircons from the paragneisses: 975, 1,161, and 1,749 Ma. These new data integrated with previous literature data indicate that (a) the Ama Drime Massif might be ascribed to the Greater Himalayan Series; and (b) the Himalayan terrane may have been located closer to both the India and Lhasa terranes during the amalgamation of the supercontinent Columbia. [ABSTRACT FROM AUTHOR]

The Penglaitan section, as the Global Stratotype Section for the Guadalupian-Lopingian boundary (GLB), displays continuous deposition with a complete succession of pelagic conodont zones across the GLB. However, there is no reliable radiometric age from the Penglaitan section itself to constrain the GLB. Here, we report SIMS zircon U-Pb ages from two bentonite layers (Bed 7c) in the Penglaitan Global Stratotype Section near the GLB. The sample PL-62-1 yields a weighted mean 238U/206Pb age of 257.1 ± 2.2 Ma, and the sample PL-62-2 yields a weighted mean 206Pb/238U age of 257.0 ± 4.2 Ma. Therefore, we consider 257.0-257.1Ma as the age of deposition of Bed 7c (the end of the C. postbitteri postbitteri conodont Zone, ca. 86 cm above the GLB), and, considering the depositional rate of chert, we suggest 258.6Ma as the age of the GLB. [ABSTRACT FROM AUTHOR]

The Attic-Cycladic Crystalline Belt in the central Aegean region represents a major tectono-stratigraphic unit of the Hellenides. The essential geological, magmatic and tectono-metamorphic features are well documented. Unresolved questions concern the time of sediment accumulation and litho- and/or tectono-stratigraphic relationships across the study area. In order to address this issue we have studied siliciclastic metasedimentary rocks from Andros Island, northern Cyclades. The sampling strategy aimed at covering the complete age range recorded by the Andros metamorphic succession. Detrital zircon U-Pb dating of nine samples indicates maximum depositional ages of c. 260 Ma for the topmost part of the metamorphic succession and of c. 160-140 Ma for rock sequences below a prominent serpentinite belt that is interpreted to outline a major tectonic contact. These age constraints are in accordance with interpretations suggesting that the metamorphic rocks of Andros represent different tectonic subunits (Makrotantalon Unit and Lower Unit) that are separated by a thrust fault. Modification of the internal structure of the Lower Unit by tectonic stacking can currently not be ascertained. The new data for the Lower Unit corroborate the importance of Late Jurassic-Early Cretaceous sediment accumulation for the larger study area. In contrast to some of the neighbouring islands, no evidence for transfer of Late Cretaceous ( c. 80 Ma) material into the Andros sedimentary environment was found. The most striking feature of the zircon populations of the Lower Unit is a remarkable age cluster at 250-200 Ma that documents the importance of Triassic igneous sediment sources. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]