The Dongco ophiolite in central Tibet represents an ideal profile of a Meso-Tethyan oceanic plateau lithosphere. In this paper, we presented petrological, geochronological, geochemical, Hf-Nd-Os isotopic and Pt-group elemental data for its primary igneous units, in an attempt to constrain the architecture and building process of oceanic plateau. The oceanic plateau basalts erupted over the Middle Jurassic (similar to 167 Ma) normal mid-oceanic ridge basalt (N-MORB)-like oceanic lithosphere dominantly composed of ultramafic and mafic plutons (epsilon(Nd)(t) = 6.5-9.5; epsilon(Hf)(t) = 15-21), at the Early Cretaceous (similar to 125 Ma). The absence of MORB-type basalt in the Dongco ophiolite, as well as the presence of diabase dikes intruding the mantle peridotite and cumulate gabbro, indicates the base of the oceanic plateau formed under an ultraslow spreading setting. The plateau basalts have positive epsilon(Nd)(t) values (3.8-5.1), geochemically with distinct ocean-island basalt (OIB) affinity, and represent plume melts that were estimated to form at a depth over 160 km (1600 degrees C potential temperature). Wehrlites at the bottom of the OIBs, isotopically consistent with the OIBs, have highly siderophile element (HSE) compositions similar to Hawaii picrite and tholeiitic basalt with suprachondritic Os isotopic compositions (Os-87/Os-188 = 0.1306-0.1329), signifying the plume melt cumulates based on modeling. The harzburgites are geochemically heterogeneous due to the plume melt-rock interaction. Type 1 harzburgites, mantle residues, have abyssal peridotite-like HSE compositions with subchondritic Os-187/Os-188 ratios (0.1182-0.1204) and ancient Re depletion model ages (1.0-1.3 Ga), indicating a complex depletion history. Type 2 harzburgites are characterized by fractionated Ir-group Pt group element compositions, higher subchondritic Os-187/Os-188 ratios (0.1211-0.1251) and younger Re depletion model ages (0.3-0.9 Ga), likely a percolation effect of plume melts with radiogenic Os isotopic compositions.

The Grand South China continent represents a Neoproterozoic tectonic assemblage formed by the accretion of the Precambrian Cathaysia, Shennong-Qinling, and Songpan-Ganzi continental blocks onto the Yangtze craton. Its eastern margin extends northward from Cathaysia via South Korea and Japan into the Bureya-Jiamusi-Khanka block, collectively preserving definitive evidence of Ediacaran - Cambrian Pan-African orogeny that correlates temporally and tectonically with the Ross - Delamerian orogen of East Gondwana. This tectonic configuration positioned the Grand South China continent within East Gondwana, culminating in the formation of the Terra Australis - Cathaysia orogenic system along southern Gondwana margin throughout the Ediacaran to Cambrian transition. This composite continent remained largely coherent throughout the Paleozoic before experiencing progressive fragmentation during subsequent tectonic events, including Yidun arc rifting during terminal Permian Emeishan LIP eruption, Nansha block separation during late Cenozoic South China Sea opening, and Song Da block displacement along the Red River fault system associated with Cenozoic Indochina extrusion. During the Triassic North China - South China collision, the Yangtze margin underthrust beneath the North China craton, triggering intense crustal shortening across the Tanlu fault during the early Mesozoic. The underthrusting and subsequent delamination of the Yangtze craton beneath North China substantially contributed to eastern North China destruction, with partial melting of Yangtze lithosphere driving widespread regional magmatism. The late Permian approach of Songpan-Ganzi promontory toward East Asia initiated westward escape and rifting of central Chinese and Indochina crustal blocks, which potentially unified before their early Paleozoic collision with North China to form the Qinling ultrahigh-pressure orogenic belt. Concurrently, the Bureya-Jiamusi-Khanka collision induced oroclinal deformation in the eastern Central Asian Orogen Belt and diachronous amalgamation of the Songliao and Xing'an blocks with the North China craton.

Lithospheric shortening can be described by one of two end-member modes: lithosphere indentation and lithospheric mantle subduction. Deciphering the difference between these modes is critical to interpret past and present orogens, and to predict their structural architecture at depth. To this goal, it is important to establish how observable upper crustal proxies reflect deep lithospheric kinematics and dynamics. Over the past few decades, geological and geophysical data have provided valuable constraints on the northern margin of the Tibetan Plateau. This margin is defined by the Qilian Shan thrust belt, which has developed in response to the far-field convergence between Indian and Eurasian plates. The primary mechanism for this development is the southward subduction of the Asian lithospheric mantle beneath the plateau. Here, we conducted numerical modeling to simulate the kinematics and upper-crust response to southward lithospheric mantle subduction. Our results show that lithospheric mantle subduction can result in upper crustal deformation that matches records in the Qilian Shan, including the broad width and architecture of the bivergent orogenic wedge, timing of fault initiation and evolution, seismicity and fault activity, topography, and geomorphology, where pure-shear shortening alone does not generate similar upper-crust proxies. The geometry of the subducting lithosphere impacts the width and asymmetry of the bivergent orogenic wedge. Our results demonstrate how records of crustal strain can be used to better interpret the deep structural architecture of orogenic wedges past and present.

The evolution of the Bangong Meso-Tethys Ocean is a hot topic, not only because the Lhasa-Qiangtang collision, following its closure possibly during the Late Cretaceous, resulted in the initial elevation of the Tibetan Plateau, but also because world-class Cu-Au polymetallic deposits discovered in central Tibet are closely related to the subduction of the Bangong Meso-Tethys Ocean. However, many fundamental aspects regarding the Bangong Meso-Tethys Ocean are still intensely debated. Here, we conducted a study on the Jiangco composite pluton of diorite porphyry (DP) and quartz monzonite porphyry (QMP) that was emplaced in the accreted Early Jurassic oceanic plateau on the southern margin of the Qiangtang block of central Tibet. Our research thus probes into how the Bangong Meso-Tethys oceanic plateau interacted with the southern Qiangtang margin and how the Bangong Meso-Tethys subduction zone evolved during and after its accretion to the continental margin in the Late Mesozoic. The DP samples were dated at similar to 170 Ma by the zircon U-Pb method and show low K and Rb but high Na and Fe contents. They have low Nb and Y contents and show a positive correlation between the P2O5 contents and SiO2 contents, exhibiting distinct S-type granite characteristics. Their high Zr contents of 194-282 ppm and intermediate (Nb/Zr)(PM) ratios of 0.95-1.17 (averaging 1.1) are consistent with the magmatic rocks emplaced in a crust-thickened orogen. Their high initial Sr-87/Sr-86 (0.7104-0.7105) and low epsilon(Nd)(t) (-13 to -12) and zircon epsilon(Hf)(t) (-12 to -8) values suggest a derivation from crustal sources. Therefore, we argue that they were produced by partial melting of the thickened southern Qiangtang lower continental crust in an accretionary orogeny triggered by the subduction of the similar to 185 Ma Meso-Tethys oceanic plateau. The QMP samples have zircon U-Pb ages of 113-116 Ma. They exhibit a distinct calc-alkaline affinity and are depleted in Nb and Ta but enriched in large-ion lithophile elements (LILEs), Th and Pb, indicative of a continental arc environment. They have a broad epsilon(Hf)(t) range (-3.1 to 2.2) but low epsilon(Nd)(t) (-4.4 to -3.8) values, demonstrating strong Nd-Hf decoupling (Delta epsilon(Hf)(t) = 2.1 to 8.1). They were produced most likely by partial melting of m & eacute;lange diapir raised from the Bangong Meso-Tethys subduction channel. These results indicate that the southern margin of the Qiangtang block underwent significant crustal thickening during the Middle Jurassic accretionary orogeny and switched to normal oceanic subduction during the late Early Cretaceous.

Mainland China has the most complex continental tectonics on Earth, making it one of the ideal laboratories for probing the tectonics and evolution of the Earth. However, no consensus has been reached regarding the basement tectonic architectures and evolution of mainland China. This paper focuses on the interpretation of aeromagnetic and seismic refraction data, closely incorporating available surface geological data, borehole data, and seismic data to trace the likely occurrences of oceanic plateau slices in the basement architecture of mainland China. We suggest that the highly positive aeromagnetic anomalies and thick high-velocity lower crustal layer indicate that the Junggar basin is floored by an oceanic plateau. The Tarim basin can be divided into a southeastern oceanic plateau block with strongly positive aeromagnetic anomalies and a northwestern passive continental margin block with weak aeromagnetic anomalies. Both blocks got amalgamated together during the late Paleoproterozoic, and the irregular, promiscuous aeromagnetic anomalies within the northwestern block are spatially consistent with and attributed genetically to the Tarim Large Igneous Province (LIP). The lower crust of the Qaidam basin is characterized by large P-wave velocity, suggesting that the basin is floored by an Early Paleozoic oceanic plateau, and the deep-seated subduction of the oceanic plateau could be responsible for the ultrahigh-pressure (UHP) metamorphism in the northern Qaidam margin during the Early Paleozoic. The western North China craton could be an assembly of multiple oceanic plateau fragments along irregular continental margins during the Paleoproterozoic. An intraplate suture (Miaowan suture) divides the Yangtze craton kernel to the east and the Shennong terrane to the west; both were amalgamated during the Neoproterozoic. The Yangtze craton kernel could be floored by an oceanic plateau basement characterized by large P-wave velocity and strongly positive aeromagnetic anomalies. All these oceanic plateau basements exhibit strong rigidity to resist later tectonic deformation and generally remain intact.

Subduction of the Bangong-Nujiang Meso-Tethys not only bred world-class Cu - Au polymetallic deposits in central Tibet but also created the initial elevation of the Tibetan Plateau during the Late Cretaceous following its final closure. Consequently, the Meso-Tethys carry critical codes for the evolution of Tethyan realm and the development of the Tibetan Plateau but some fundamental aspects still remain poorly explored. Here we proposed an embryonic intra-oceanic subduction event in the Bangong-Nujiang Meso-Tethys during the Late Jurassic based on investigations of adakitic granodiorites intruded within the Dongco ophiolite suite, central Tibet. These granodiorites were dated at 150-156 Ma by zircon U-Pb isotopes and geochemically display an affinity with high-silica adakite (Sr/Y = 24-47; La/Yb = 6-16), specifically marked by high SiO2, Al2O3 and Na2O contents but low MgO, CaO + Na2O contents as well as extremely low Yb and Y contents. They have (87Sr/86Sr)i ratios varying from 0.7061 to 0.7069, epsilon Nd(t) values of -0.83 to 0.50, and epsilon Hf(t) values of 3.3 to 8.9 (with one exception at -5.0), showing a distinct Nd-Hf isotopic decoupling (Delta epsilon Hf(t) = 2.1-7.6; Delta epsilon Hf(t) = epsilon Hf(t)- 1.55 x epsilon Nd(t)-1.21). Geochemical modeling indicates that they were derived from partial melting of subducted Meso-Tethyan oceanic crust and moderate amounts of sediments. Residual plagioclases in the source region likely resulted in relatively lower Sr and La contents than typical high-silica adakite. Combined with previous studies, we suggest that the Dongco granodiorites formed in the early stage of an intra-oceanic subduction zone in the Bangong-Nujiang Meso-Tethys where subsidence of colder lithosphere inductively commenced along an active transform fault bounded by younger lithosphere during the Late Jurassic. This embryonic intra-oceanic subduction possibly occurred locally and was very short-lived.

The fine siliciclastic rocks of the Early Permian Shoushangou Formation in West Ujimqin Banner, central Inner Mongolia are a hot spot for Late Paleozoic oil and gas exploration and hold key implications for the tectonic evolution during the closure of the Paleo-Asian Ocean (PAO). Therefore, the sedimentary characteristics of the Shoushangou Formation in West Ujimqin Banner, along with the geochemical and Sm-Nd isotopic characteristics of the clastic rock samples in Well MXD1, were investigated to privde additional constraints on its provenance and tectonic background. The mudstones contain large proportions of quartz, feldspars and igneous debris, and the CIAcorr (0.52-0.66), the A-CN-K plot and the lack of Ce anomalies in REE show a weakly weathered provenance and the chemically unaltered parent rocks, suggestive of the proximal deposition and rapid burial. Slip-roll beddings, gravity flow, Bouma sequences and the (trace) fossil assemblages in the profile indicate that the Shoushangou Formation is mainly a shallow- (semi-)abyssal submarine fan and the lithological information indicates the presence of microfaces including main and lesser water supply channels, interchannels, lobes, natural levees. Furthermore, a narrow continental shelf above the submarine fan and the concentrated zircon age population of the Shoushangou formation suggest that the tectonic background is most likely a retroarc basin. The Al2O3/TiO2 ratio (19-24, average 22), the multivariable principal element source identification diagram and the plots of Th/Sc vs. Zr/Sc and Co/Th vs. La/Sc indicate that the source is mainly felsic, with a minor proportion of intermediate rocks. Trace elemental characteristics (e.g., Th, Zr, Sc, Co, Nd, and REE) deomonstrate that the tectonic setting of the Shoushangou Formation is confined by continental arcs. The whole rock Sm-Nd isotopic spectra of the Carboniferous and Permian strata indicate that the Baolidao arc is the main source of central Inner Mongolia. Additionally, the comparison of the Nd model ages and the zircon U-Pb ages of the Baolidao arc and other entities in the Central Asian Orogenic Belt (CAOB) is in support of a prolonged subduction of the PAO since similar to 510 Ma, suggesting that the Baolidao arc was developed from the southern continental arc of the original South Mongolia microcontinent. Accordingly, it is suggested that the Shoushangou Formation was deposited in a retro-arc basin which was strongly influenced by the steep subduction of the PAO and the results collectively suggest that the PAO terminated no earlier than the middle to late Permian.

The formation of most jadeitites and other jadeite‐rich rocks (jadeitoids) during subduction is thought to occur by precipitation (P‐type) or metasomatism (R‐type) by infiltration of Na‐Al‐Si‐rich aqueous fluids because of the compositional similarity of the rocks to inferred subduction fluids. Whether these rocks can form by isochemical metamorphism (I‐type) during subduction is still hotly debated. A characteristic of I‐type jadeitoid is that it exhibits a similar prograde metamorphic record as associated eclogite, in contrast to P‐ and R‐type jadeitite and jadeitoids that are typically enclosed in serpentinite derived from the mantle wedge and either lack a prograde metamorphic history (R‐type and P‐type) or probably experience a prograde history (R‐type) that is difficult to discern owing to the high variance of the jadeite‐dominated assemblages and alteration by subduction fluids. The recently discovered Baqing (eastern‐central Tibet) jadeitoid is enclosed by quartzo‐feldspathic schist and has a peak metamorphic assemblage of almandine + jadeite/omphacite + phengite/paragonite + rutile + quartz, similar to eclogite. Abundant mineral inclusions in almandine, especially rutile inclusions with increasing Zr contents from the core to rim of almandine, provide an opportunity to further decode the jadeitoid‐forming processes. In this study, pseudosections and Zr‐in‐rutile thermometry, together with conventional geothermobarometers, were employed to decipher the metamorphic history of Baqing jadeitoids. Two analysed Baqing jadeitoids exhibit a similar clockwise P–T path, starting from early metamorphic conditions of 5–7 kbar, 350–440°C, to different peak conditions (27–29 kbar, 730–760°C, or 20–23 kbar, 670–710°C), followed by relatively consistent retrograde metamorphic conditions of 6–7 kbar, 530–600°C. This result indicates a similar subduction history to the Baqing eclogite. In addition, the Baqing jadeitoids show similar geochemical characteristics to some Na‐rich, K‐depleted and Ca‐depleted sedimentary rocks or plagiogranite. Therefore, we propose an isochemical genesis for the Baqing jadeitoid, rather than a metasomatic origin.

As the front of the northeastward-growth region of the Qinghai-Tibetan Plateau since the Cenozoic, arcuate fold-and-thrust belts are the main features of local tectonic deformation. However, the formation mechanism of these arcuate structures is still an open question. We present 3D finite-element models with elasto-plastic rheology to understand the formation-evolution of arcuate folds here comprising real regional fault-zones including the Haiyuan, Xiang Shan-Tianjing Shan, Yantong Shan, and Niushou Shan faults since similar to 10 Ma. The reference-model equivalent-plastic-strain (EPS) concentration zones develop outwardly-NE in spatio-temporal sequence, with development geometry and timing in good agreement with the geologic fault-zone structures. Our reference-model-based sensitivity analysis suggest that the horizontal northeastward compression of the region being bounded by a frictional vicinity (rigid Alxa and Ordos blocks hindering the advancement) have the dominant control on the formation and evolution of these arcuate fold-and-thrust belts perpendicular to the contraction axis. In contrast, the likely-small rotations imprinted by the Ordos and Alxa blocks and the minor shearing of the Qinghai-Tibetan Plateau, have only secondary effects. An additional, generic sensitivity analysis reveals that the folds' horizontal curvature per unit horizontal shortening-displacement increases with the friction on the bounding vicinity, and this result could be considered for other scenarios of Earth and other planets. Historical regional earthquakes of M > 6 are mostly located in the simulated EPS concentration zones: the 1920 Haiyuan and 1709 Zhongwei earthquakes occurred on the Haiyuan and Xiang Shan-Tianjing Shan faults, respectively, well correlated with our model high-EPS concentration zones.

The Permian Tarim large igneous province (LIP), which contains both large volumes of basalt and silicic volcanic sequences, has been intensively studied in the past decades, but some issues still remain controversial, including the petrogenesis of each component in the LIP, their interrelationships, and the geodynamic processes that produced them. In the Halahatang area of the northern Tarim Basin, a well-developed eruptive suite composed of basalt and trachy-andesite has been penetrated by numerous boreholes, which provide us an opportunity to better understand these issues. In this paper, we carried out an integrated study on the eruptive suite, including petrography, geochronology and geochemistry. The results indicate that the eruptive suite formed at around-290 Ma, generally synchronous with the main episode of magmatism within the Permian Tarim LIP. The basalts have similar compositions to typical oceanic island basalts (OIBs), which have alkaline, high-Ti and sodic compositions and show enrichments in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs). Whole-rock Sr-Nd isotopes are slightly enriched, with eNd(t) and (87Sr/86Sr)i values from-4.5 to-3.4 and 0.7065 to 0.7086, respectively. The trachy-andesites are alkaline, metaluminous and ferroan, and display highly enriched LREEs and LILEs. High Ga/Al ratios and Zr + Nb + Ce + Y values constrain their A-type affinity and A1-type nature. They have eNd(t) values from-8.2 to-4.5 and (87Sr/86Sr)i values from 0.7083 to 0.7189, more enriched than those of the basalts. Based on these results, we proposed that the different compo-nents in the igneous suite have close petrogenetic relationships. The alkali basalts may have been formed by mantle plume-derived melts coupled with somewhat assimilation of continental crust, while the trachy-andesites were products of variable fractionation of the basaltic magmas involving more conti-nental crustal components in the magma evolution. In combination with the existing results in Tarim, we further suggested that the alkali basalt and trachy-andesite suite may have been generated via a crust-mantle interaction process related to the Permian mantle plume activity.(c) 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

When impinging on the lithosphere in spreading ridges or intra-plate settings, the asthenospheric mantle can significantly influence plate tectonics. However, the active role of the asthenospheric mantle on subducting slabs remains poorly understood. The main reason for this dispute is the lack of typical geochemical mafic rocks in the subduction zone. In this paper, we first report the Early Jurassic (187 Ma) Yurongguo Nb-enriched basalts in the western segment of the Bangong-Nujiang suture zone. These samples show typical Nb-enriched basaltic features with high Na2O, TiO2, Nb (>7 ppm), high Nb/Th (average =11.05), Nb/La (average = 1.37) and Nb/U (average = 72.98) ratios. Unlike the adakite-related Nb-enriched basalts, the Yurongguo Nb-enriched basalts formed from the mixture of magmas derived from upwelling asthenosphere (20-30%) and depleted mantle (70-80%) in the spinel lherzolite region (<70 km). We conclude the Yurongguo Nb-enriched basalts were formed in the fore-arc basin setting with the influence of slab rollback, which occurred under the intra-oceanic subduction. Two southward intra-oceanic subductions may exist in the western part of the Bangong-Nujiang Tethyan Ocean in the Jurassic. The Early Jurassic (200-180 Ma) intra-oceanic subduction formed the fore-arc basin, probably accompanied by asthenospheric mantle activity at the same time, followed closely by flat subduction due to the oceanic plateau. After a period of geological stabilization, the Late Jurassic (170-150 Ma) was the period when the spreading of the little ocean basin ceased, and the second intra-oceanic subduction occurred. We proposed an oceanic plateau-subducted oceanic slab interaction and overriding intra-oceanic subduction model for the MesoTethyan subduction in the western Tibetan Plateau.

In this paper, we present an integrated study of petrology, zircon U–Pb geochronology, whole-rock geochemistry, and zircon Lu–Hf isotopes for the basic–intermediate dykes in the western Gonghe basin, northeastern Qinghai–Tibetan Plateau. LA–MC–ICP–MS zircon U–Pb dating indicates that these dykes were emplaced in the Middle Triassic (240 ± 1.6 Ma). Geochemically, these basic–intermediate dykes are characterized by enrichments in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs; e.g. K, Rb, and Pb), coupled with depletions in high-field-strength elements (HFSEs; e.g. Nb, Ta, and Ti). These geochemical features, along with the relatively low zircon εHf values (−7.2 to 1.6), suggest that these mafic dykes were originated from enriched mantle metasomatized by subduction-related fluids in a back-arc extensional environment. Literature investigations indicate that Middle Triassic mafic dykes are widespread in central China and are geochemically of arc affinities. Therefore, a regional back-arc extensional event occurred in central China during Middle Triassic time, which was likely caused by rollback of the subducting Kunlun–Animaqin Paleo-Tethyan slab.

We present zircon U-Pb ages, whole-rock geochemistry, and Sr-Nd-Pb isotopes for the newly discovered granites on North Island, Xisha Islands, at the northwestern margin of the South China Sea. These peraluminous granites yield a crystallization age of ca. 254 Ma, and are characterized by high SiO2 contents (71.28-78.36 wt%), K2O/ Na2O ratios (0.9-1.8, average = 1.3), and Fe numbers (0.73-0.96, average = 0.87). The granites are enriched in light rare earth and large-ion lithophile elements, depleted in high-field strength elements, and have marked negative Eu anomalies. These features and high (87Sr/86Sr)i ratios of 0.7090-0.7113 and negative epsilon Nd(t) values of-6.5 to-2.1 indicate that the granitic magmas were derived by partial melting of crustal rocks with some contributions from mantle-derived melts. The magmas underwent crustal assimilation and fractional crystalli-zation during magma ascent. These new and literature data suggest the Southeast Asian margin was strongly influenced by the closure of the eastern Paleo-Tethyan Ocean and subsequent post-orogenic extension during the latest Permian-Early Triassic. This inference is consistent with a diachronous, clockwise collision between the Indochina and South China blocks.

This is the dataset for the paper "Contrasting Collision-induced Far-field Orogenesis Controlled by Thermo–rheological Properties of the Composite Terrane" that has been submitted to "Geophysical Research Letters".

The role of the Meso-Tethyan oceanic plateau in the growth of the Tibetan Plateau is debated. In this paper, we report coexistence of large-scale mid-ocean ridge basalt (MORB)-like and enormous ocean island basalt (OIB)type mafic rocks from the Dongco ophiolitic rocks of the Bangong-Nujiang Suture Zone. The MORB-like rocks host tholeiitic geochemical characterizes, and have supra-subduction zone affinity such as enrichments in large ion lithophile elements (LILEs), depletions in high field strength elements, high epsilon(Nd)(t) values (+6.5 to +9.5) and low initial Sr-87/Sr-86 ratios (0.7033-0.7050). The OIB-type rocks have an alkaline affinity and are characterized by enrichments in LILEs and light rare earth elements, strongly negative Sr anomalies, variable epsilon(Nd)(t) values of 3.7 to +7.3, and low initial Sr-87/Sr-86 ratios ranging from 0.7034 to 0.7050. Metamorphic zircons from amphibolites in the sole of the ophiolitic rocks yielded U-Pb ages of 104-100 Ma. Detrital zircons from the upper Cretaceous sandstone of the Abushan Formation (K(2)ab) yielded young U-Pb ages of 100-86 Ma. Considering the regional geology, we suggest that the Dongco MORB-like rocks were derived from a depleted mantle source and formed from an intra-oceanic subduction-related setting, representing remnants of normal oceanic crust, whereas the OIB-type rocks were derived from an enriched mantle source representing remnants of a Meso-Tethyan oceanic plateau. Our preferred hypothesis is that the Meso-Tethyan oceanic plateau experienced a phase of accretion at 104-100 Ma, which probably increased local subduction erosion of the upper plate and providing provenance for the deposition of the K(2)ab sandstone. The maximum depositional ages of K(2)ab sandstone constraint the minimum ages for closure of the Bangong-Nujiang Tethys Ocean most likely at 100-86 Ma.

The Tarim basin not only is one of the main targets for hydrocarbon exploration in China, but also hosts the Early Permian LIP, thereby providing an ideal laboratory to investigate how the LIP eruptions interact with the petroleum system in the volcanic-affected basins. Six major second-order domes were identified in the first-order dome that involves the entire Tarim LIP, based on seismic probing and lithofacies and stratigraphic observations in boreholes and the stratigraphic sections. These second-order domes are characterized by abundant Permian basaltic dykes and volcanic craters, indicative of the origin from the LIP eruption. They also are the sites of the almost all Paleozoic oil and gas reservoirs in the Tarim basin. Dating on authigenic illites collected from 20 Silurian bituminous and oil-saturated sandstone samples in the Tarim basin, along with literature data, indicates that hydrocarbon charge and emplacement in the Paleozoic reservoirs prevalently occurred during 300-255 Ma, approximately concurrent with the eruption of the Tarim LIP lavas (300-262 Ma). Therefore, we propose that the LIP eruption not only created the second-order domes that provided space for the oil and gas charge but also triggered the rapid release of hydrocarbon through the volcanic vents, thereby controlling the formation of Paleozoic oil and gas fields in the Tarim basin. (c) 2021 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

timely and essential to exchange new ideas in the international community and provoke 34 and promote studies in this field.In the collection of this Research Topic, 11 contributions were published, with a 36 focus on the recent advances in sedimentary geochemistry and isotopes at whole-rock 37 and/or single mineral scale and their applications to tectonic and environmental published practice examples on a regional scale that can be tracked and referred to by 43 researchers in the same field.The collection covers the following several major themes.

Late Mesozoic uplift of the Gangdese arc occurred prior to the India-Asia collision and was important in the evolution of the Tibetan plateau, but the geodynamic mechanisms that drove this process are unclear. In this paper, we report geochronological, petrological, geochemical, and Sr-Nd-Hf isotopic data for intermediate-acidic igneous rocks from the western Gangdese arc. These igneous rocks were emplaced at 87-67 Ma and are characterized by enrichments in light rare earth and large-ion lithophile elements, depletions in high-field-strength elements, high (Sr-87/Sr-86)(i) ratios (0.7074-0.7116), and low epsilon(Nd)(t) (-7.5 to -4.1) and epsilon(Hf)(t) values (-16 to 0.8). These magmas were most likely derived by high-temperature (960-1200 degrees C) partial melting of the thickened crustal materials, with minor mantle input, related to post-orogenic lithospheric delamination. The increasing epsilon(Nd)(t) and epsilon(Hf)(t) values and decreasing initial Sr isotope ratios from the ca. 87 Ma diorites to ca. 67 Ma diorites and rhyolites indicate an increasing mantle contribution as delamination proceeded. Estimated pressure conditions for the high-Sr/Y gabbroic diorites indicates the magmas were derived from crust at pressures of up to 19 kbar (i.e., a depth of similar to 66 km). Therefore, the western Gangdese arc had been thickened during the Late Cretaceous, possibly due to the flat-slab subduction of Neo-Tethyan oceanic lithosphere and coeval collision of the Qiangtang-Lhasa terranes.

SUMMARY The propagation of Tibetan Plateau high-elevation towards the Asian interior remains poorly understood. We conduct a series of 2-D viscoelastic plastic finite element models addressing the development of the Liupan Shan fold-and-thrust belt with multiple detachments in the NE Tibetan Plateau. We focus on the spatio–temporal relations of the Liupan Shan fold-and-thrust belt and dynamic mechanisms of growth in the NE margin of Tibetan Plateau during the late Cenozoic. Our models, consisting of a seismically-constrained two-layer-crust (of variable thicknesses) plus lithospheric mantle consider tectonic horizontal contraction and the influence of elastoplastic materials, including Model 1 (only the upper crust is elastoplastic), Model 2 (both the upper crust and the middle part of the lower crust are elastoplastic) and Model 3 (the whole lithosphere is elastoplastic). The results show that Model 1 can only reflect the properties of shallow detachment layer. Models 2 and 3 can better reflect the properties of multidetachment layers and approximately represent the process of fold-and-thrust belt formation and evolution; thus suggesting the importance of plastic rheology in the deep crust. In addition, Model 3 suggests that the pre-existing fault near the Moho below Liupan Shan is activated during the evolution process of ∼8 Ma. In summary, the results embody that the initiation and evolution of the fold-and-thrust belt depend on detachment structures: the deep and shallow detachments control the evolution of surface deformation and fold-and-thrust belt altogether. The simulated surface deformation is generally consistent with actual surface elevation distribution. Moreover, the growth of the Liupan Shan range may represent an expansion of the NE Tibetan Plateau toward the Ordos basin vicinity. Additionally, the tectonically driven uplift of Liupan Shan area supports the general crustal shortening tectonic mechanism of the Tibetan Plateau.