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The Qinling Orogenic Belt (QOB), formed by the subduction and collision between the North China Block (NCB) and the South China Block (SCB), is a key area for exploring the tectonic process and timing of integration between the two blocks. A range of tectonic models have been proposed with regard to the subduction and collision of the QOB, but controversy in the timing and integration process still remain debatable, especially in the late Palaeozoic orogeny. The South Qinling Belt (SQB) is located between the Shangdan and Mianlue sutures, widely dispersed sediments outcropped in the SQB provide natural ground for the detrital zircon study, that could trace the sedimentary provenance and continental crustal evolution history, thus provide important evidence for the late Palaeozoic evolutionary processes in the QOB. In this study, we applied a detailed geochronological U‐Pb zircon dating of the Silurian, Devonian and Permian sedimentary rocks from the SQB. The result of the U‐Pb isotopic data shows distinct age populations at 439–474 Ma of the Silurian samples, ca. 400–490 Ma of the Devonian samples and 260–310 Ma of the Permian samples, respectively. By comparing the regional geochronological data, we sum up that the Silurian detrital zircons are mainly derived from the SQB and the northern margin of SCB (N‐SCB), the Devonian detrital zircon age populations are dominated by the North Qinling Belt (NQB) and SQB and the Permian sediments mainly stemmed from the southern margin of the North China Block (S‐NCB) and the NQB. A mutual age population of the Devonian sediments at ca. 400–490 Ma from the NQB constrains the closure of the Shangdan Ocean between the NCB and the SCB before the middle Devonian times. Ca. 260 ~ 380 Ma age population of the Permian sediments show similarities with the age data from the northern margin of the NCB, indicating an uplift event of NQB before the late Permian, and further constrains the closure of Mianlue ocean later than Permian times. [ABSTRACT FROM AUTHOR]

Achieving a reliable closure time of a back‐arc ocean is an essential aspect in studies on detailed tectonic processes of an active continental margin and arc–continent collision. This is particularly the case for the northern Qinling Orogen, which records the accretion of the North Qinling Arc (NQA) onto the North China Block (NCB) after the Erlangping back‐arc ocean closure. Sedimentological, petrological and geochronological signatures from the Ordovician successions in the southern Ordos reveal a tectonic transition from passive continental margin to peripheral foreland in the southern NCB at the beginning of Katian. Sedimentological and geochronological investigations reveal an abrupt shift of accelerating basin subsidence and deepening at the earliest Katian, separating ca. 300‐m‐thick shallow‐marine carbonate shelf assemblages from overlying ca. 2000‐m‐thick deep‐water carbonate slope and turbidite associations. Zircon age spectra of the Katian turbidites are characterized by early‐Palaeozoic and Neoproterozoic age clusters, which are different from those of the Middle Ordovician quartz arenites sourced merely from the NCB basement. Instead, these age patterns match well with those of the coeval successions in the northern NQA, indicating a spatially linked abyssal deposystem. Stratigraphic architecture deciphers a typical foreland basin geometry, involving, from south to north, northward‐propagating turbiditic wedge, northward‐backstepping carbonate slope and progressively shoaling carbonate platform, embodying foredeep, forebulge and backbulge, respectively. These characteristics of basin‐fill evolution reflect the northward migration of the flexural wave as a dynamic response to the northward expansion of the thickened NQA thrust wedge. Together with the other geological and geochronological data, our new insights indicate a southward subduction polarity of the Erlangping back‐arc oceanic crust followed by its termination at ca. 450 Ma, which was earlier than that of the main Proto‐Tethyan Shangdan Ocean between the NCB and South China Block. Our new data provide an updated view of the complex history of the Proto‐Tethys closure during the Gondwana assembly. [ABSTRACT FROM AUTHOR]

In this study, we conducted sandstone petrography analyses and determined detrital zircon U–Pb ages and Hf isotopes for sandstones collected at different stratigraphic levels of the lowest strata of the Laiyang Group. All results nearly point to an evolutionary trend for the source regions of the strata. The detrital zircon U–Pb results reveal multiple age groups at 140–123 Ma, 810–700 Ma, and 2,500–1,750 Ma, but variable age proportions for two sandstones (19LY‐01Z and ‐05Z) collected at lowermost and middle levels of strata, respectively, but only one unimodal age mode at ca. 1,850 Ma for the uppermost sandstone 19LY‐09Z. Provenance analysis illustrates that the lower strata likely include two source regions, including the Jiaobei Terrane and the Sulu orogen, whereas the upper strata appeared to have one dominant source region (i.e., Jiaobei Terrane). Framework modes of sandstones display that lower samples contain more metamorphic lithic fragments, which corresponds to the recycled orogenic field in the Q‐F‐L diagram, while middle‐upper samples are enriched in feldspars but deficient in lithics and plot in the basement uplift field of the Q‐F‐L diagram. This compositional variation reflects an evolution of the source regions from the Sulu Orogen to the Jiaobei Terrane, completely consistent with the observation of an increase in the amount of detrital zircons sourced from the Jiaobei Terrane, but decreasing detrital zircons from the Sulu Orogen in an upward order. This shift in the provenance of sediments reflects two tectonic events including exhumation of the Sulu Orogen to the surface before sedimentation of the Laiyang Group, and a rapid uplift of the Jiaobei Terrane after ca. 125 Ma following removal of lithospheric mantle. [ABSTRACT FROM AUTHOR]

New detrital U–Pb zircon ages from the Sanandaj–Sirjan metamorphic zone in the Zagros orogenic belt allow discussion of models of the late Neoproterozoic to early Palaeozoic plate tectonic evolution and position of the Iranian microcontinent within a global framework. A total of 194 valid age values from 362 zircon grains were obtained from three garnet-micaschist samples. The most abundant detrital zircon population included Ediacaran ages, with the main age peak at 0.60 Ga. Other significant age peaks are at c. 0.64–0.78 Ga, 0.80–0.91 Ga, 0.94–1.1 Ga, 1.8–2.0 Ga and 2.1–2.5 Ga. The various Palaeozoic zircon age peaks could be explained by sediment supply from sources within the Iranian microcontinent. However, Precambrian ages were found, implying a non-Iranian provenance or recycling of upper Ediacaran–Palaeozoic clastic rocks. Trace-element geochemical fingerprints show that most detrital zircons were sourced from continental magmatic settings. In this study, the late Grenvillian age population at c. 0.94–1.1 Ga is used to unravel the palaeogeographic origin of the Sanandaj–Sirjan metamorphic zone. This Grenvillian detrital age population relates to the 'Gondwana superfan' sediments, as found in many Gondwana-derived terranes within the European Variscides and Turkish terranes, but also to units further east, e.g. in the South China block. Biogeographic evidence proves that the Iranian microcontinent developed on the same North Gondwana margin extending from the South China block via Iran further to the west. [ABSTRACT FROM AUTHOR]

The Neoproterozoic Zhoutan Group, located at the conjunction area between the Yangtze and the Cathaysia Blocks, preserves an important record of the Neoproterozoic sedimentary system of the South China Block. However, its accurate depositional age, provenance, and tectonic affinity remain poorly studied. Here, we report new LA-ICP-MS detrital zircon U–Pb age data of four meta-sedimentary samples from the Zhoutan Group in the Nancheng area for complemental decipherment of its sedimentary and tectonic histories. Concordant detrital zircon ages reveal proportions of 54% latest Mesoproterozoic to early Neoproterozoic (ca. 1050–820 Ma), 24% early Paleoproterozoic (ca. 2500–2150 Ma), and 22% late Paleoproterozoic to early Mesoproterozoic (ca. 2000–1500 Ma) populations. Youngest detrital zircon age clusters exhibit a consistent weighted mean age of ca. 827 Ma, suggesting the maximum Tonian depositional age of the Zhoutan Group. Provenance interpretations reveal that the detritus of investigated samples were mainly sourced from the proximal Jiangnan Orogen with some additionally derived from the Cathaysia Block, the interior Yangtze Block, and/or extraneous terranes. In addition, the appearance of some later early Palaeozoic-aged (ca. 437 Ma) metamorphic rims and grains suggest that the Zhoutan Group has locally experienced an intense metamorphism during the early Palaeozoic (Silurian) time, which has been consistently recorded by the Neoproterozoic meta-strata in the Cathaysia Block. These new data, together with those from previous studies, indicate that the Zhoutan Group belongs to the early Neoproterozoic sedimentary successions between the Yangtze and the Cathaysia Blocks. Subsequently, it might be thrusted onto the present side of the Cathaysia Block during later tectonic processes and was affected by locally metamorphism during the Silurian time. Thus, such observations suggest that the potential border between the Yangtze and the Cathaysia Blocks should be to the north of the current position of the Zhoutan Group. [ABSTRACT FROM AUTHOR]

The earliest record of Himalayan detritus in the Himalayan foreland and the erosion sequence of different lithotectonic units of the Himalaya are critical for reconstructing collision and crustal deformation of the orogenic belt. In this study, bulk‐rock major, trace and rare earth elements of 19 fine‐grained clastic sedimentary rock samples from Eocene to Pliocene strata of the Bengal Basin were examined to study their provenance and erosion of the Himalaya. Combining with previous detrital zircon age data from the Bengal Basin, Nepal foreland basin, and South Tibet, we suggest that detritus from the uplifted Tethyan Himalayan Sequences and the Gangdese Arc had not been carried into the Himalayan foreland at least before Late Miocene, and that the Bengal Basin was in a passive continental margin setting from Eocene to Early Miocene, receiving detritus from a felsic sedimentary rock source. The earliest Himalayan detritus recorded in the Eocene strata of Bengal Basin were probably derived from the antecedent sedimentary cover of the Greater Himalayan crystalline rocks. We assume that the lack of Cretaceous Gangdese detritus in the Himalayan foreland from Eocene to Middle Miocene is due to a geomorphic barrier between the Tethyan Himalaya and the Himalayan foreland. Detritus from the Greater Himalayan crystalline rocks were first recorded in the Middle–Late Miocene Boka Bil Formation of the Bengal Basin, which is consistent with the uplift and exhumation time of the Greater Himalayan Sequences. [ABSTRACT FROM AUTHOR]

The Late Palaeozoic dynamic setting of the Ordos Basin in the southwestern North China Craton (SW‐NCC) is poorly constrained due to limited understanding on the source‐to‐sink relation. This study presents integrated provenance clues from the Permian strata in the southwestern Ordos Basin to trace the sources and to discuss the tectonic setting of the basin in the SW‐NCC. The reconstructed palaeocurrent directions of these Permian sediments generally point to the northeast and suggest the dominant sedimentary influx from the southwest. Modal composition analysis shows the Permian deposits have an overwhelming derivation from mixed sources containing orogeny, continental block, and magmatic arc. Zircons from the lower section yield major age clusters of ~300–270 Ma and ~2,500–1,700 Ma. While, zircon age spectra for the upper section are marked by the abundance of ~1,000–800 Ma and ~500–400 Ma ages, and the lack of Permian populations. Sources of the lower section were interpreted to be the arc terrane along the southern border of SW‐NCC, in contrast, sources of the upper part were attributed to the Central Qilian Block. Zircons of ~300–270 Ma indicate significant magmatic activities in a rapidly uplifting continental arc, yielding an additional clue for the subduction and the existence of the Mianlue Ocean in the northeastern Palaeo‐Tethys. The changes in provenance and depositional rate at the Middle Permian indicate the rapid subsidence along with the intensive uplift of the continental basement in the SW‐NCC. These signatures likely infer that the back‐arc basin may have evolved into a compressional setting at that time. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Triassic detritus in the northwestern Ordos were mostly sourced from the Alxa Massif. • Post-collision related basin formed in the northwestern Ordos at Middle-Late Triassic. • The Alxa Massif was the western extension of the North China Craton during Triassic. Abstract The Helanshan Tectonic Belt is situated among the Qilian Orogenic Belt to the southwest, the Alxa Massif to the west and the Ordos Block to the east. The Helanshan Tectonic Belt has received increasing attention since it was argued as the plate boundary separating the Alxa Massif from the Ordos Block, and hence Alxa Massif was isolated from the North China Craton during Triassic. The Middle to Upper Triassic strata in the northwestern Ordos and the Helanshan Tectonic Belt witnessed the tectonic evolutionary processes between the Alxa Massif and the Ordos Basin, hence are pivotal to understand the relationship between the Alxa Massif and the North China Craton. In this work, integrated paleocurrent orientation, gravel component, sandstone modal composition and detrital zircon U–Pb isotopic analyses were applied to trace the source area and reconstruct the source-to-sink relations between the Alxa Massif and Ordos Basin. The southeast orientated paleocurrent directions suggest detritus in the northwestern Ordos were mostly sourced from the northwest. Clastic compositions reveal a mixed orogeny provenance, including magmatic arc and continental block sources. Detrital zircons from four sandstones in the Helanshan Tectonic Belt yields four major LA-ICPMS U-Pb age groups of 2600–2200 Ma, 2000–1700 Ma, 480–400 Ma and 350–200 Ma, suggesting multiple-sourced provenance. Comparing to the magmatic records in the Alxa Massif and the Qilian Orogenic Belt, the Triassic detritus in the Helanshan Tectonic Belt were mainly from the Alxa Massif with additional supplements from the Qilian Orogenic Belt, which finally debouched to the lacustrine in the interior Ordos Basin to the southeast. Triassic basin evolution of the northwestern Ordos was further associated with post-collision in the Alxa Massif after the closure of the Paleo-Asian Ocean. [ABSTRACT FROM AUTHOR]

• The Quanji Group was mainly deposited in a rift basin during ∼1780–1600 Ma. • The Quanji Group was sourced from the basement of Olongbuluke Terrane. • The Olongbuluke Terrane has a close tectonic affinity to the North China Craton. The late Paleoproterozoic tectonic processes of the Olongbuluke Terrane in the northern Qaidam of northwestern China remain unclear due to rare contemporaneous metamorphic and magmatic records. The sedimentary succession of the Quanji Group preserves detailed geological information of erosion, transportation and deposition, which is pivotal for constraining the late Paleoproterozoic tectonics of the Olongbuluke Terrane. The Quanji Group comprises conglomerate-sandstone of nearshore facies and mudstone-dolomite of tidal flat facies in the lower and upper sections, respectively, displaying an upward fining and transgression sequence. Together with featured sedimentary structures, the facies assemblage and vertical sequence suggest that the Olongbuluke Terrane has experienced a basin evolution of initial rifting, rifting climax and passive continental margin during ∼1780–1640 Ma. Four samples collected from the low to top positions within the profiles yield quite similar detrital zircon age patterns with two distinct clusters of 2510–2216 Ma and 2062–1728 Ma. These detrital zircon ages coincide with those of magmatism–metamorphism in the basement of Olongbuluke Terrane, suggesting the detritus were sourced from the Olongbuluke Terrane itself. The zircons with ages of 2510–2216 Ma display εHf (t) ratios from −2.29 to +6.81 and corresponding T DM2 ages of ∼3.1 to 2.5 Ga, suggesting they were originated from reworking of the Meso- to Neoarchean juvenile crust with mantle inputs or mantle derived rocks. In comparison, the zircons with ages of 2062–1728 Ma exhibit εHf (t) ratios ranging from −17.4 to −0.1 and T DM2 ages of ∼3.6 to 2.5 Ga, indicating their origin in partial melting of the Paleo- to Neoarchean crust. The two sets of zircons display T DM2 ages with three peaks of ∼2.9 Ga, ∼2.7 Ga and ∼2.5 Ga. Comparing with those of the other main blocks all over the world, all the above detrital zircon U-Pb ages and T DM2 ages together with the late Paleoproterozoic tectono-stratigraphic processes suggest that the Olongbuluke Terrane has a Precambrian tectonic affinity close to the western North China Craton. [ABSTRACT FROM AUTHOR]

• The QOB had a close tectonic affinity to the SCB from Mesoproterozoic to Early Neoproterozoic. • The Hf isotopic variation of the detrital zircons was associated with the exterior and interior orogens. • The change of tectonic setting was attributed to the transition from Columbia to Rodinia. The Qilian Orogenic Belt (QOB) in Northwest China consists of three distinct terranes: North Qilian, Central Qilian, and South Qilian, which have experienced complex rifting and converging. Here, we present new U-Pb ages and Hf isotopes of detrital zircons from the Neoproterozoic and Mesoproterozoic sedimentary rocks in the QOB to constrain the tectonic affinity of the different terranes and provide new evidence to the transition from Columbia to Rodinia. Two Mesoproterozoic zircon samples from the North and the Central Qilian display similar age spectra with a dominant population varying from 1.21 Ga to 1.78 Ga. The population show two age peaks at ~1.5 Ga and ~1.75 Ga and have same range of ε Hf (t) values from −9.1 to +9.8. Except for this population, the rest zircons yield Paleoproterozoic or even older ages with a peak at ~2.45 Ga. These results suggest that the three terranes were once of a united block in the late Mesoproterozoic. The two Neoproterozoic samples from the Central Qilian and the South Qilian both have a main population of ages at 0.85–1.0 Ga and a minor population peaked at ~2.45 Ga. Their zircon ε Hf (t) values indicated that the source rocks of the main population were dominantly composed of recycled crustal materials. Because of the comparable and homogeneous age patterns and Hf isotopic compositions of Proterozoic detrital zircons, the QOB has a close relationship to South China from Mesoproterozoic to Early Neoproterozoic. Our zircon ages and Hf isotopic data indicate that the juvenile components increased at 1.6–1.2 Ga, which response to an exterior orogen that newly-formed crust has replaced the lower crust possibly triggered by slab retreat or upwelling of asthenosphere materials related to the breakup of Columbia. In contrast, the abundant addition of the reworking materials at 1.2–0.8 Ga reacts to an interior orogen characteristic because continental collision was involved in the convergent of Rodinia. This changing, therefore, was a response to the transition from breakup of Columbia to the assembly of Rodinia. [ABSTRACT FROM AUTHOR]

The Koralpe-Wölz nappe system as part of the Upper Austroalpine nappes is generally characterized by medium to high grade (amphibolite and eclogite facies) Eo-Alpine metamorphism contemporaneous or subsequent to Alpine nappe stacking. In addition, the investigated units related to the Koralpe-Wölz nappe system were affected by Permian high-temperature – low-pressure metamorphism, basically related to lithospheric thinning subsequent to the Variscan orogeny. While the metamorphic conditions and the timing of the metamorphic events are well constrained, very little is known about the protoliths ages of the widely distributed metasediments. They comprise huge masses of micaschists and paragneisses with intercalations of marbles, quartzites, amphibolites and eclogites. In this study we present first data from U/Pb dating of detrital zircons measured on samples of several complexes of the Koralpe-Wölz nappe system. Additionally, we give an outlook on the samples which are already sampled and in progress at present. These age data will give information about potential provenance areas, maximum ages of sediment deposition and hints on the sedimentary environment. Zircon age spectra of the Koralpe Complex show a main peak of Ordovician and Carboniferous values. The maximum deposition age of the sedimentary precursor is defined by the youngest zircon detrital age of 301 ± 15 Ma. However, the youngest zircon ages determined from this unit are in the range of 250 to 285 Ma. These zircons formed during the Permian upper amphibolite facies imprint and confirm ages measured on magmatic garnet from Permian pegmatites (Thöni 2002). A micaschist from the Saualpe Complex is dominated by zircons with ages of around 90 Ma. These ages are contemporaneous with the Eo-Alpine tectonometamorphic event. The zircon age distribution in metasediments from the Rappold Complex is dominated by Cadomian ages. Youngest ages are in the range of 330 to 380 Ma indicating the upper age limit for the sedimentation of this unit. The available detrital zircon data indicate different provenance areas for the metasediments of the Koralpe Complex and Saualpe Complex with respect to the Rappold Complex. They indicate a late Carboniferous depositional age for parts of the Koralpe Complex which is surprisingly young. An enlarged data set including the samples in progress will help to reconstruct the Carboniferous paleogeographic arrangement of the Austroalpine basement units in the future. [ABSTRACT FROM AUTHOR]