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[Display omitted] • Grenville-age terrane is identified in the Qilian orogen. • The Precambrian basement of the Qilian orogen is divided into four distinct mega-sequences. • ∼475 Ma metamorphism was related to the subduction of the Proto-Tethys Ocean. The Qilian orogen at the northeastern margin of the Tibetan Plateau records a complete history from continental breakup to oceanic basin evolution and back to continental collision during the Neoproterozoic to Paleozoic interval. The Qilian Ocean, as a branch of the Proto-Tethys Ocean, was connected to the Iapetus Ocean but is lesser known than its two more famous counterparts. This paper presents zircon U-Pb and biotite-muscovite 40Ar/39Ar isotope data from the Yemananshan Complex in the western Central Qilian belt to assess the age and provenance of late Mesoproterozoic-early Paleozoic successions in the Qilian orogen. The results indicate the Central Qilian belt is characterized by Late Mesoproterozoic-early Neoproterozoic orogenesis with magmatism from 1200 Ma to 900 Ma and clastic metasedimentary rocks deposited between 1050 and 920 Ma. Statistical analysis of detrital zircon data and auxiliary temporal information from the Qilian orogen affirms the notion that sedimentation occurred in four distinct megasequences: (1) 1950–1850 Ma, the oldest known strata, (2) 1250–920 Ma, during Grenvillian-Sveconorwegian orogenesis, (3) 840–760 Ma, the disintegration of Rodinia, and (4) 650–550 Ma, which is typical of the orogenic belts that sutured the Gondwana continental blocks. Metamorphic zircon and 40Ar/39Ar isotope data indicate early Paleozoic metamorphism at ca. 475 Ma, which overlaps with magmatic activity associated with arc-back-arc basin development in the Central Qilian belt, which was associated with subduction of the Proto-Tethys in eastern Gondwana. [ABSTRACT FROM AUTHOR]

[Display omitted] • Permian zircon U-Pb age spectra are different from those of Silurian and Devonian. • The Silurian-Devonian detritus was from the proximal igneous rocks. • Increased ca. 430 Ma zircons indicates the onset of foreland stage. • The Permian detritus was from the basement of the Cathaysia Block. • Foreland basin was replaced by intraplate basin in Late Paleozoic. Integrated analysis of zircon U-Pb dating, in-situ Lu-Hf and whole-rock geochemical data was performed on Silurian-Permian siliciclastic rocks from the Lower Yangtze region (LYZ), northeastern South China Block, to understand the tectono-sedimentary evolution during the Paleozoic. These rocks have a high chemical index of alteration (CIA = 71.3–91.8) and variable index of compositional variability (ICV = 0.2–3.5), indicating intensive weathering. The high Zr/Sc ratios (12.1–75.3) indicate that their sources contain recycled old sediments. The Silurian and Devonian samples contained abundant detrital zircons with ages of 1.0–0.8 Ga and 460–420 Ma. However, the Permian samples show bimodal age spectra with peaks at ∼ 1800 Ma and 280–260 Ma. Integrated with published geochronological data, the proportion of the 460–420 Ma zircons drastically increased from the Early to Mid-Silurian and decreased in the Early Carboniferous, indicating two tectonic transformations, respectively. Based on these variations and relative paleogeographic data, we suggest three evolution stages with different provenances for the LYZ: (1) from Cambrian to Ordovician, the LYZ region inherited the Cryogenian tectonic framework of South China Block, receiving detritus from East Gondwana. (2) from Silurian to Devonian widespread uplift in South China Block led to the development of an isolated foreland basin with independent sedimentary sources and (3) from Carboniferous to Permian, subduction of the Paleo-Pacific plate exposed the Paleoproterozoic basement of the Cathaysia Block, providing detritus for the LYZ intraplate basin. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ca. 311 Ma granite was derived from biotite dehydration melting of metagreywacke. • The ca. 283 Ma granite experienced extreme differentiation and melt–fluid interaction. • The granitic rocks record the tectonic transition from syn- to post-collision (ca. 320–280 Ma). • Hf isotopic mapping reveals significant crustal reworking. Peraluminous granitoids can provide crucial insights into crustal reworking. Here we report a geochemical study of two Late Paleozoic peraluminous granitic plutons in the South Tianshan Belt, NW China, to constrain their crustal reworking history. Zircon U-Pb analyses yield ages of 311 ± 4 Ma for the garnet-bearing biotite granite and 283 ± 4 Ma for the garnet-bearing muscovite granite. The garnet-bearing biotite granites exhibit peraluminous affinity (ASI = 1.04–1.11), high CaO/Na 2 O, low Rb/Sr, and negative ε Nd (t) (−8.7 to –7.5) and zircon ε Hf (t) (–8.4 to –0.8) values with ancient crustal model ages, which suggest they were derived from dehydration melting of metagraywacke. The garnet-bearing muscovite granites, containing manganese garnet, show high SiO 2 (72.3–76.8 wt%) and strongly peraluminous (ASI = 1.14–1.22), high Rb/Sr (37.8–128.9), low Zr/Hf (16.61–31.80) and Nb/Ta (3.05–5.71), and exhibit tetrad REE patterns (TE 1 , 3 = 1.05–1.27), which can be ascribed to high-degree fractional crystallization accompanied by the interaction with fluids. They show negative ε Nd (t) values (–8.6 to –6.6) and variable zircon ε Hf (t) values (–4.9 to +2.7), implying ancient crustal with minor juvenile crustal sources. In combination with the occurrence of peraluminous magmatic rocks of the South Tianshan Belt, we propose that the peraluminous magmatic rocks were formed by the partial melting of ancient crustal rocks from the passive continental margin of the Tarim Craton, which represents an important crustal reworking event in the Central Asian Orogenic Belt. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ordovician to Triassic maximum depositional ages are determined from Sibumasu in NW Thailand. • 1200–900 Ma, 650–500 Ma and 2500–2460 Ma populations are present in all 8 NW Thai detrital samples. • Hf signatures change provenance from Gondwana in Ordovician-Permian to Indosinian in Triassic. • Our comparison with published detrital data is inconsistent with composite Sibumasu models. The evolution of the Sibumasu Terrane forms a principal component in the history of the Tethys Oceans with the northward movement of Gondwana-derived terranes creating the Asian continent that we recognise today. While there are various reconstructions for the palaeoposition of the Sibumasu Terrane during the Proterozoic and Paleozoic, the terrane is commonly placed outboard of the northwest Australian margin in the Gondwanan supercontinent. In this study, U–Pb and Lu–Hf isotopic information has been collected from detrital zircons of Paleozoic and Mesozoic sedimentary rocks obtained from the Sibumasu Terrane in northwest Thailand. This is the first zircon Hf analysis from these sedimentary sequences. These new data are statistically and visually compared with data from Sibumasu, Indochina, Sukhothai, West Burma and Tethyan Himalayas terranes along with the terranes of China, India and Western Australia. Our detrital data are consistent with other published data indicating consistent sources across the Sibumasu Terrane, inconsistent with composite terrane reconstructions. However, temporally, the detrital ages change from older Paleozoic sedimentary sequences (sourcing zircons from Neoproterozoic and older "Gondwanan" sources) to latest Permian-Triassic sedimentary units with Indosinian zircon sources. This change is consistently reflected in this study through both the U–Pb ages and Hf signatures with Proterozoic age peaks characteristic of Gondwana and younger Indosinian sources being consistent with granitoids emplaced through the amalgamation of Thailand. The temporal changes in the isotopic systems reflect the movement of the Sibumasu Terrane from the northwest Australian margin of Gondwana to its collision with the terranes of present-day Asia. [ABSTRACT FROM AUTHOR]