As the world's highest and largest plateau, the uplift of the Tibetan Plateau profoundly reconfigured Asian physiography, reorganized atmospheric circulation, and drove long-term changes in surface environments and biodiversity, serving as a unique natural laboratory for investigating coupled geological-climatic-ecological processes. Integrated Earth-system research on the Tibetan Plateau therefore provides robust scientific foundations for addressing global challenges such as climate-change adaptation and mitigation, ecosystem conservation, and sustainable resource management. The Tibetan Plateau exhibits pronounced geological heterogeneity, comprising an assemblage of amalgamated terranes that have progressively amalgamated over the past similar to 300 Myr through successive subduction of intervening oceanic basins along suture zones. These multiple subduction and collision events resulted in the formation of heterogeneous lithosphere and variable histories of crustal deformation and surface elevation change across the Tibetan Plateau. Quantitative paleoaltimetry has become the most robust approach for reconstructing the timing, magnitude, and spatial pattern of plateau growth. Mostly applied quantitative paleoaltimetries include hydrogen and oxygen isotope paleoaltimetry, clumped-isotope thermometry, nearest living relative techniques and coexistence approach based on plant and animal fossils and palynology, moist enthalpy and biomolecular proxies. Over the past three decades, extensive paleoaltimetric reconstructions of the Tibetan Plateau have been carried out by integrating diverse proxies with paleoclimate simulations, targeting major orogenic belts (e.g., Himalaya, Gangdese, Central Watershed, Kunlun) and intermontane basins (e.g., Central Tibetan Valley, Yarlung Tsangpo Valley, Hoh Xil Basin, Qaidam Basin). With that, the scientific consensus regarding the uplift of the plateau has evolved from an early paradigm of uniform (monolithic) uplift to a more refined framework emphasizing differential and spatiotemporally variable uplift processes. Present research supports an uplift scenario in which initially discrete orogenic belts progressively coalesced into a uniform high plateau. Following Neo-Tethys subduction and the onset of India-Asia collision at similar to 65 Ma, the Gangdese and Central Watershed Mountain attained elevations above similar to 4,500 m prior to similar to 50 Ma, while the intermontane Central Tibetan Valley between them remained at a relatively low elevation of similar to 1,700 m, producing a "two mountain ranges sandwiching a low elevation basin" topography. Between similar to 45 and 25 Ma, progressive lithospheric removal and isostatic readjustment drove uplift of eastern Tibetan Plateau and the Central Tibetan Valley to elevations exceeding similar to 3,000 m, producing the earliest high-altitude plateau topography. A Mediterranean-like climate emerged in eastern Tibetan Plateau-characterized by warm and dry summer and cool and wet spring-autumn-and promoted the development of biodiversity hotspots in the Hengduan Mountains represented by the Relu and Markam Basins. By the Miocene, rapid uplift of the Himalaya and northern Tibetan Plateau brought those regions to near-modern elevations and completed the formation of the present-day plateau. During this period, the South and East Asian monsoon systems stabilized into near-modern regimes, promoting the emergence of montane monsoon forests akin to contemporary ecosystems. As a result, intensified precipitation and headwater formation rendered the plateau the source region for Asia's major rivers and contributed to the development of fertile ecosystems in downstream basins, especially in modern South China. Despite these advances, ongoing research on the uplift of the Tibetan Plateau and its interactions among multiple Earth-system spheres remains limited by sparse paleoaltimetric data and mismatches between proxy reconstructions and model simulations. Future priorities include developing high-resolution regional Earth-system models, integrating proxies with simulations for systematic cross-validation, and advancing next-generation paleoaltimetric techniques to clarify the mechanistic linkages between tectonic evolution and climate change. These efforts constitute critical steps for understanding the Tibetan Plateau's Earth system and its implications for regional resources and environments.

The North Qilian Orogenic Belt (NQOB) preserves key fragments of Precambrian continental crust along the northern margin of the Proto-Tethyan system. One such fragment is the Beidahe Block (BDHB) that forms the focus of this study. To resolve the crustal architecture, provenance, and tectonic affinity of the BDHB, we present zircon U-Pb and Lu-Hf data from Paleoproterozoic-Neoproterozoic metasedimentary and magmatic rocks in the western NQOB. Detrital zircon spectra from the Beidahe and Zhulongguan Groups yield maximum depositional ages of ca. 1.4 Ga and 728 Ma, respectively, and display major clusters at 2.45 Ga, 1.7-1.6 Ga, 1.55-1.30 Ga, and 0.95-0.74 Ga, indicating mixed sediment input from Archean-Paleoproterozoic basement and Mesoproterozoic-Neoproterozoic magmatic sources. Magmatic zircon ages of ca. 1.65 Ga (granitic gneiss), 1.09 Ga (garnet amphibolite), and a metamorphic age of 497 Ma record late Paleoproterozoic crustal growth, previously unrecognized Mesoproterozoic mafic magmatism, and Early Paleozoic high-grade metamorphism related to subduction initiation. Zircon Lu-Hf compositions are dominated by negative epsilon Hf(t) values with T-DM2 model ages of 3.5-1.4 Ga, demonstrating extensive reworking of ancient continental crust with limited juvenile input during Mesoproterozoic-Neoproterozoic magmatism and sedimentation. Comparative detrital zircon analysis shows that the BDHB closely resembles the Central Qilian Block (CQB), sharing the characteristic similar to 0.95 Ga and similar to 1.60 Ga peaks while lacking the similar to 1.45 Ga and similar to 1.90 Ga signals typical of the Alxa Block. This affinity suggests that the BDHB formed a Rodinia-derived microcontinent along the southern margin of the North Qilian Ocean. The provenance pattern and metamorphic record collectively indicate a southward/bidirectional subduction polarity during Early Paleozoic Ocean closure.

[Objective]The Eastern Himalayan Syntaxis and its southeastern region serve as a critical channel for the eastward extrusion or/and expansion of Tibetan Plateau material.The deformation/rheology mechanisms and seismic anisotropy of the lithosphere provide key insights into plateau uplift and lateral growth.[Methods]This study investigates lower-crustal garnet pyroxenites(27-44 km depth)and lithospheric mantle spinel lherzolites(50-78 km depth)from the Ailao Shan-Red River shear zone and adjacent regions.This study integrates petrographic analysis,microstructural observations,measurements of crystallographic preferred orientations(CPOs),metamorphic-deformation thermobarometry,and whole-rock seismic velocity modeling to constrain the lithospheric seismic anisotropy and its tectonic implications.[Results]Our key findings include:(1)Microstructural analysis reveals that garnet in lower-crustal pyroxenites behaves as a rigid phase with rotational deformation,while clinopyroxene accommodates strain via dislocation creep.In the lithospheric mantle,olivine exhibits both A-type(high-temperature,low-pressure simple shear)and AG-type(melt-present)CPOs;orthopyroxene and clinopyroxene also deform predominantly by dislocation creep,indicating polyphase plastic deformation and static recrystallization.(2)Seismic velocities show distinct layering:garnet pyroxenites exhibit VP=8.01-8.07 km/s and VS=4.54-4.57 km/s with weak anisotropy(AVP=0.6%-1.4%,AVS=0.7%-1.1%),whereas spinel lherzolites display higher velocities(VP=8.03-8.08 km/s,VS=4.60-4.61 km/s)and stronger anisotropy(AVP=3.8%-8.0%,AVS=3.0%-6.6%).(3)The velocity controls differ between lithologies:in pyroxenites,the garnet content dominates the bulk seismic velocity,while the anisotropy correlates with the clinopyroxene content;in lherzolites,the seismic properties are primarily controlled by olivine,while orthopyroxene and clinopyroxene exert a diluting effect,and the deformation intensity significantly influences the anisotropy.(4)From the middle crust to the lithospheric mantle,a vertical velocity model reveals stepwise increases:mica schist(VP=6.12-6.46 km/s)→granodiorite(VP=6.69-6.78 km/s)→amphibolite(VP=6.30-6.69 km/s)→ garnet pyroxenite(VP=8.01-8.07 km/s)→ spinel lherzolite(VP=8.03-8.08 km/s),with the amphibolite layer(VS=3.59-4.01 km/s)acting as a key interface for crust-mantle velocity transitions.[Conclusion]Integrated with published geophysical data,we propose a tectonic model wherein:(1)mid-lower crustal amphibolites and partial melts are the primary sources of crustal anisotropy;(2)mantle anisotropy reflects southeastward lithospheric extrusion driven by asthenospheric upwelling,with clear crust-mantle decoupling.[Significance]Our new data provide critical constraints on the lithospheric deformation and crust-mantle decoupling beneath the Eastern Himalayan Syntaxis and its southeastern region by linking mineral-scale deformation mechanisms with large-scale seismic anisotropy.This enhances our understanding of the uplift and lateral growth of the Tibetan Plateau in the Cenozoic.

The Tibetan and Iranian plateaus are the two most prominent orogenic plateaus on the present Earth built by continental collision. However, the timings of initial collision and suturing in the Himalaya and Zagros remain debated. In this Review, we summarize the timings, similarities and differences between the India–Eurasia collision and the Arabia–Eurasia collision, by comparing their sedimentary, magmatic, metamorphic, structural and palaeomagnetic records. The India–Eurasia collision is tightly constrained to have initiated in the central Himalaya at 65–59 Ma, possibly progressing towards the western and eastern Himalayas by 55–50 Ma. By contrast, the initial collision in the Zagros is loosely constrained to ~34 Ma, with a possibility of diachronous collision, younging to the southeast. Similarities between the two collisions include pre-collisional accretionary tectonism and magmatism, syn-collisional deformation and sedimentation, and crustal thickening. Apparent differences in lithospheric dynamics, deformation styles and metamorphism are attributed to variations in convergence rates, durations and magnitudes. Future research should focus on data-driven modelling and geophysical imaging beneath the Tibetan and Iranian plateaus to further quantify the geodynamic processes and driving forces contributing to continuous plate convergence, plateau formation and their surface impacts. The collision of the Indian, Arabian and Eurasian plates formed the Tibetan and Iranian plateaus, but its timing and processes remain debated. This Review explores the evidence behind initial collision estimates and discusses the tectonic and geodynamic implications.

Understanding the Cenozoic growth history of the Himalaya-Tibetan Plateau (HTP) is essential for elucidating the underlying geodynamic mechanism and interactions among topography, biosphere and atmosphere. However, the spatial-temporal evolution of the HTP, especially that of the Paleogene Central Tibetan Valley (CTV), remains hotly debated. In this study, through radiometric geochronology, plant assemblages, oxygen and clumped isotope paleoaltimetries, we reconstruct the uplift history of the east-west-oriented Luolong Basin in eastern Tibet. Results show that the Luolong Basin was at 0.6 (+0.2/-0.4) km at ca. 54-46 Ma, then rose to 2.9 ± 0.9 km at ca. 44 Ma. The newly discovered Luolong Flora indicates the Eocene CTV extending into eastern Tibet, and that the valley was higher in the east, sloping to the west, inferring a westward progressive rise of the valley floor. Integrated evidence from paleomagnetism, magmatism and seismic tomography suggests that the birth of the near modern plateau is attributed to the stepwise delamination (drip) of the subducted Lhasa lithosphere from east to west.

In the southeastern Tibetan Plateau, region‐scale dextral strike‐slip shear zones, crucial for India‐Asia convergence, were investigated along the Dulongjiang shear zone near the Eastern Himalayan Syntaxis (EHS). Structural, kinematic, and geochronological data from Dulongjiang and Nabang regions in western Yunnan, China, reveal dextral strike‐slip shearing between 30 and 15 Ma. Various rocks were affected by moderate‐temperature shear deformation (∼450–550°C), inferred from microstructures and quartz CPO patterns, during dextral strike‐slip and exhumation of the shear zone. Combined with structures of pre‐, syn‐, and post‐shearing leucogranites, zircon U‐Pb dating indicates that the dextral shear along the shear zone began in the Early Oligocene (30–29 Ma) subsequent to the India‐Asia collision. Micas in mylonitic granites yield 40Ar/39Ar ages, suggesting that the principal dextral shear deformation occurred approximately between 18 and 15 Ma. The Dulongjiang shear zone is linked to the Parlung, Nabang shear zone, and Sagaing Fault, forming a regional Cenozoic dextral shear system around the EHS. The study, combined with tomographic anomalies beneath the India‐Asia collision zone, highlights distinct lithospheric‐scale evolution in southeastern and eastern Tibet. Continuous intracontinental strike‐slip shearing indicates a tectonic shift from Tibetan extension to block rotation around the EHS. From 30 to 15 Ma, slab tear, accompanied by clockwise rotation and dextral strike‐slip shearing, suggests a warmer geodynamic setting influenced by hot mantle flow associated with ongoing subduction of the Indian lithosphere. Oligocene‐Miocene dextral strike‐slip shearing around the EHS, linking southwards with the Sagaing Fault, may correspond to the rotation necessary for slab to bend, stretch, and eventually tear beneath the region.

The Bangong-Nujiang Ocean played an important role in the formation of the Tibetan Plateau prior to the Cenozoic India-Eurasia collision. However, there are still uncertainties about the subduction polarity and timing of the Lhasa-Qiangtang collision. We conducted sandstone petrologic and detrital zircon U-Pb-Hf isotopic analyses on the Cretaceous Wada melange, trench-fill strata and Duoni Formation in the Basu area in the eastern Bangong-Nujiang Suture Zone. The Wada melange (-114 Ma) exhibits block-within-matrix features and a detrital zircon U-Pb age spectrum characterized by multiple peaks at 114-180 Ma, 200-300 Ma, and 1800-2000 Ma. The trench-fill strata consist of coherent chert, sandstone, and mudstone, with a detrital zircon age spectrum dominated by a single peak at -120 Ma. The epsilon Hf(t) values of the 110-300 Ma detrital zircon grains in the Wada melange and trench-fill strata range from -20 to +10 and are consistent with those of the South Qiangtang Terrane. The epsilon Hf(t) values of the -120 Ma detrital zircons are all negative, and these grains were likely derived from a remnant Cretaceous arc in the South Qiangtang Terrane to the north. These data suggest that the accretionary wedge was derived from the South Qiangtang Terrane during the northward subduction of the Bangong-Nujiang Ocean. The Duoni Formation (-113 Ma) represents peripheral foreland basin deposits with the Lhasa Terrane as the basement. Provenance analysis indicates that these deposits received clastic material mainly from the South Qiangtang Terrane and to a lesser degree from the North Lhasa Terrane. Our results suggest that the Lhasa-Qiangtang collision occurred in the Early Cretaceous (-113 Ma) in the eastern segment of the Bangong-Nujiang Suture Zone.

The absence of a fully preserved foreland basin system in the central-eastern Yarlung-Zangpo Suture Zone (YZSZ) of Tibet has hindered the understanding of the initial timing of the India-Asia collision along strike. To address this issue, remnant foredeep and wedge-top deposits of the foreland basin system are described from the Tethyan Himalaya sequence and the YZSZ in the Xigaze area. The foredeep is defined by the olistostrome of the Zongzhuo Formation, which consists of matrix and blocks, including chert, limestone, sandstone and volcanic rocks. Based on the matrix properties, the Zongzhuo Formation is divided into two units: a lower member (Zhilong unit) with a matrix composed of black shale and thin layers of siltstone and an upper member (Yongla unit) with a matrix composed of distinctly red shale or yellow-green siliceous mudstone with interbedded siltstone and limestone. The Zongzhuo Formation is dated to 65-57 Ma by detrital zircon U - Pb chronology and radiolarian assemblages. In the YZSZ, the Puxia and Jiabi units are interpreted as wedge-top deposits consisting of mudstone matrix and exotic blocks, such as sandstone, chert and limestone. The maximum depositional ages (MDAs) of the sandstone blocks from both units are ca. 65-59 Ma. Detrital zircon provenance analysis and trace element data exclude an intraoceanic arc origin and point to a source from the Gangdese arc and recycled accretionary wedge in the suture zone. Therefore, we propose that the initial collision between India and Asia occurred at 65 Ma in the central-eastern YZSZ.

Southeastern (SE) Tibet forms the transition zone between the high interior Tibetan Plateau and the lowlands of southwest China. So understanding the elevation history of SE Tibet, a biodiversity hotspot, enlightens our understanding of the interactions between tectonics, monsoon dynamics and biodiversity. Here we reconstruct the uplift history of the Markam Basin, SE Tibet, during the middle-late Eocene based on U - Pb dating, plant fossil assemblages, and stable and clumped isotope analyses. Our results suggest that the floor of the Markam Basin was at an elevation of 2.6 +/- 0.9 km between 42 Ma and 39 Ma, where the mean annual air temperature (MAAT) was 13.2 +/- 2.4 degrees C. The basin then rose rapidly to 3.8 (+0.6/-0.8) km before 36 Ma. Integrated with existing paleoelevation data, we propose that the high plateau boundary (similar to 3.0 km) of SE Tibet formed during the late Eocene. Numerical climate modeling with realistic paleo-landscapes shows that with the rise of SE Tibet, a Mediterranean-like climate developed in the region characterized by bi-modal precipitation with two wet seasons in boreal spring and autumn. The high topographic relief of SE Tibet, coupled with this distinctive Mediterranean-like climate system, helped develop the high biodiversity of the Hengduan Mountains.

40Ar/39Ar同位素定年技术是一种在K/Ar同位素定年法基础上发展出来的另一种同位素定年方法,利用在核反应堆中对含钾样品进行快中子照射,达到使39 K衰变成39 A r,测定40 A r*/39 A r比值来计算样品的年龄.随着现代稀有气体同位素分析新技术研究的迅速发展,含钾样品的40 A r/39 A r同位素定年技术依靠其高准确性和高精度,已经发展成为当今最先进可靠和最具主要价值的岩石矿物同位素定年技术手段之一,从而被人们广泛地应用于各种重要的地质事件的精确定年,并为地质年代表提供"金钉子"般的年龄制约.首先总结了40 A r/39 A r同位素定年技术的发展历史、原理、样品处理分析等,然后重点阐述了应用40 A r/39 A r法这一同位素定年技术在青藏高原生长演化研究中如何解决关键性的科学问题,最后对同位素定年技术的发展作出了展望.

The Indian passive margin has preserved several pulses of magmatism during and after the disassembly of Gondwana since the late Paleozoic, providing valuable insights into the long-term magmatic evolution of various passive margins, including the Indian passive margin. In the Yumai Complex, eastern Tethyan Himalaya, a pulse of Late Triassic alkaline volcanism (ca. 227–216 Ma) is evident. The Late Triassic volcanic rocks are mildly alkaline to tholeiitic basalts with minor ultrabasic rocks, similar in geochemistry to within-plate flood basalts. The TiO2 contents (1.46–3.38 wt%, mainly >2 wt%), (La/Yb)N values (4.05–7.50), εNd (t) values (+4.86 to +6.98), and results from partial-melt modeling suggest that the basalts likely originated from garnet peridotite. Elemental and Sr-Nd systematics of magmatic rocks emplaced during the Triassic indicate oceanic island basalt (OIB) components in the magma source, interpreted as enriched mantle components rather than crustal contamination products. Spatiotemporal and geochemical patterns of magmatism reveal that the bulk compositions of the basalts changed from enriched OIB-like to depleted mid-ocean-ridge basalt (MORB)–like compositions. This phenomenon likely resulted from the evolving nature of the rifting basin, changing from a nascent continental setting to a mature ocean basin. The Triassic magmatism in the Tethyan Himalaya can be attributed to remnant lithospheric instability arising from the prolonged rifting of eastern Gondwana, leading to the formation of a magmatically passive margin.

Abstract We present two robust and well‐dated paleomagnetic poles from upper Eocene and Oligocene volcanics in the Urumieh‐Dokhtar magmatic arc, Central Iran. These two poles place Iran ∼3.7°–3° of latitude south of its present position between ca. 40 and 23 Ma. Our new paleomagnetic declination data indicate that the Central Iran block may have experienced a ∼11.6° clockwise rotation since the Late Eocene. We integrated our new data with the retrodeformed margins of the Zagros collision zone and contemporaneous Arabia positions to better constrain the age and configuration of the Arabia and Eurasia assembly process. In our model, the Arabia‐Eurasia collision occurred first in the western Main Zagros suture between ca. 35 and 30 Ma and then diachronously spread eastwards. Our paleogeographic reconstruction and initial continental collision timing supports the Arabia‐Eurasia collision as a first‐order driver of global cooling, Red Sea rifting, and Mediterranean extension.

In Western Himalayan Syntaxis, the India‐Asia continental collision occurred at ca. 50 Ma, while its uplift history and exhumation mechanism are still in dispute despite decades of studies. A new type of eclogite was found in Naran, located ca. 30 km southwest of the Upper Kaghan Valley. Phase equilibrium calculations and thermobarometer performed on the Naran eclogite documented the peak‐P metamorphic condition of 720–780°C at 2.4–2.8 GPa. Two further exhumation stages were identified with the first one at high‐P granulite‐facies conditions of 750–800°C at 1.6–1.9 GPa, and the second at amphibolite‐facies conditions of 550–630°C at 0.5–0.8 GPa. SIMS U‐Pb dating of metamorphic zircons yielded an age of 46 ± 2 Ma, which is interpreted to constrain the high‐P metamorphism age along the northwestern margin of the Indian plate. SIMS U‐Pb dating of rutile yielded a cooling age of 26 ± 3 Ma, which is interpreted as cooling age in the amphibolite facies. The average speculated exhumation rate of the Naran massif (∼3 mm a −1 ) was much lower than that recovered from the Upper Kaghan Valley massif (86–143 mm a −1 ). The tectonic and metamorphic evolution of the whole Western Himalayan Syntaxis shows the difference in temporal and spatial change within the Paleogene era, indicating the inconsistent exhumation histories of the continental slices. Such a multi‐slice exhumation process was probably related to the closure of the Neo‐Tethys ocean and the break‐off of the Indian lithospheric slab.

Accretionary complexes offer important source of information for studying the subduction history and source-to-sink system and neighboring terranes. In this study, we conducted field mapping, detrital zircon U-Pb age and trace element analyses, and electronic microprobe composition analysis of detrital Crspinel in sandstones from the Cretaceous Bainang accretionary complex in the central part of the Yarlung-Zangpo suture zone (YZSZ). The Bainang accretionary complex is located in a structural window that is mainly composed of Xigaze ophiolite, Late Triassic-Early Cretaceous radiolarite chert with a Late Cretaceous hemipelagic siliceous shale matrix, and Late Cretaceous sandstone. The obtained detrital zircon geochronological dataset confirms two spectra. Detrital zircons from the Canggasaba and Lianxiang sections are dominated by Precambrian grains with subordinate numbers of Mesozoic grains clustering at 243-178, 164-117, and 109-91 Ma, consistent with the melange and trench-fill Rongmawa Formation, and all the trace elements of the Mesozoic grains match continental arc affinity. Provenance analysis suggests that detritus in these sections was mainly derived from the eastern part of the Gangdese arc and the central-northern Lhasa terrane. These results confirm the existence of the ancestral Lhasa River that transports sediments from the eastern Lhasa terrane to the subduction zone and further westward along the east-west axial system parallel to the trench. Conversely, the Qiajiu section is mainly dominated by Mesozoic detrital zircon grains, representing submarine fan deposits that were sourced from the adjacent Gangdese arc and transported through a local north-south-flowing river system. Detrital Cr-spinel compositions and detrital zircon trace elements from the Qiajiu section also revealed the contribution of ophiolites. Considering the abundance of Eurasia-affinity detrital zircons, this study supports the single subduction model that was developed along the southern margin of the Lhasa terrane. (c) 2022 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

The uplift of eastern Tibet, Asian monsoon development and the evolution of globally significant Asian biodiversity are all linked, but in obscure ways. Sedimentology, geochronology, clumped isotope thermometry, and fossil leaf-derived numerical climate data from the Relu Basin, eastern Tibet, show at similar to 50-45 Ma the basin was a hot (mean annual air temperature, MAAT, similar to 27 degrees C) dry desert at a low-elevation of 0.6 +/- 0.6 km. Rapid basin rise to 2.0 +/- 0.9 km at 45-42 Ma and to 2.9 +/- 0.9 km at 42-40 Ma, with MAATs of similar to 20 and similar to 16 degrees C, respectively, accompanied seasonally varying increased annual precipitation to > 1500 mm. From similar to 39 to 34 Ma, the basin attained 3.5 +/- 1.0 km, near its present-day elevation (similar to 3.7 km), and MAAT cooled to similar to 6 degrees C. Numerically-modelled Asian monsoon strength increased significantly when this Eocene uplift of eastern Tibet was incorporated. The simulation/proxy congruence points to a distinctive Eocene Asian monsoon, quite unlike that seen today, in that it featured bimodal precipitation and a winter-wet regime, and this enhanced biodiversity modernisation across eastern Asia. The Paleogene biodiversity of Asia evolved under a continually modifying monsoon influence, with the modern Asian monsoon system being unique to the present and a product of a long gradual development in the context of an ever-changing Earth system. (c) 2022 Science China Press. Published by Elsevier B.V. and Science China Press.

Reconstructing the Paleogene topography and climate of central Tibet informs understanding of collisional tectonic mechanisms and their links to climate and biodiversity. Radiometric dates of volcanic/sedimentary rocks and paleotemperatures based on clumped isotopes within ancient soil carbonate nodules from the Lunpola Basin, part of an east-west trending band of basins in central Tibet and now at 4.7 km, suggest that the basin rose from <2.0 km at 50 to 38 million years (Ma) to >4.0 km by 29 Ma. The height change is quantified using the rates at which wet-bulb temperatures (Tw) decline at land surfaces as those surface rise. In this case, Tw fell from ~8°C at ~38 Ma to ~1°C at 29 Ma, suggesting at least ~2.0 km of surface uplift in ~10 Ma under warm Eocene to Oligocene conditions. These results confirm that a Paleogene Central Tibetan Valley transformed to a plateau before the Neogene.

Reconstructing the evolution of the Sumdo Paleo-Tethyan Ocean (SPTO) is important for understanding the transition from the Paleo-Tethyan system to the Neo-Tethyan system. The existence of the SPTO is inferred from the presence of an (ultra-)high pressure metamorphic belt and dismembered ophiolite bodies that separate the southern Lhasa and northern Lhasa terrane. This paper presents new geochronological and geochemical data for the Luobadui Formation in the Lhasa terrane. The geochemical difference between the Lower Luobadui volcanics and the Upper Luobadui volcanics suggests a source transition from a depleted mantle source to an enriched mantle source, which indicates continental-arc subduction. The integrated geological evidence suggests that the SPTO initially opened during the late Carboniferous (ca. 304 Ma), as verified by the earliest record of oceanic crust. Our new data for the Luobadui volcanic rocks, together with the metamorphic and sedimentary records, support northward subduction of the SPTO lithosphere beneath North Lhasa, most likely starting during the Early Permian (ca. 275 Ma) and lasting until the Middle Permian (ca. 260 Ma). The main closure of the SPTO occurred during Middle-Late Triassic (ca. 240-220 Ma), as recorded by medium-pressure metamorphism and syn-colli-sional magmatism. The Wilson cycle of the SPTO is hereby reconstructed, providing significant insights into the amalgamation of the Tibetan Plateau.

The timing of the initial India–Asia collision and the mechanisms that led to the eventual formation of the high (>5 km) Tibetan Plateau remain enigmatic. In this Review, we describe the spatio-temporal distribution and geodynamic mechanisms of surface uplift in the Tibetan Plateau, based on geologic and palaeo-altimetric constraints. Localized mountain building was initiated during a Cretaceous microcontinent collision event in central Tibet and ocean–continent convergence in southern Tibet. Geological data indicate that India began colliding with Asian-affinity rocks 65–60 million years ago (Ma). High-elevation (>4 km) east–west mountain belts were established in southern and central Tibet by ~55 Ma and ~45 Ma, respectively. These mountain belts were separated by ≤2 km elevation basins centred on the microcontinent suture in central Tibet, until the basins were uplifted further between ~38 and 29 Ma. Basin uplift to ≥4 km elevation was delayed along the India–Asia suture zone until ~20 Ma, along with that in northern Tibet. Delamination and break-off of the subducted Indian and Asian lithosphere were the dominant mechanisms of surface uplift, with spatial variations controlled by inherited lithospheric heterogeneities. Future research should explore why surface uplift along suture zones — the loci of the initial collision — was substantially delayed compared with the time of initial collision.

The configuration and timing of the Arabia‐Eurasia continental collision, part of the broader Alpine‐Himalayan collisional system, remains controversial. We conducted sandstone petrology, detrital zircon U‐Pb‐Hf isotopic and trace element analysis, and Cr‐spinel electron microprobe geochemical analysis of samples from Paleocene to Miocene peripheral foreland strata in interior Fars, southern Iran. These data were used to test competing models for ophiolite obduction and Arabia‐Eurasia collision. In addition, we applied these data to compare the history of outward and upward growth of the Zagros and Himalayan‐Tibetan segments of the Alpine‐Himalayan collisional orogenic belt. The first appearance of radiolarian‐rich chert conglomerate, 100–90 Ma detrital zircons with positive ɛHf(t) values from +1 to +20 and midocean ridge geochemical affinity, and suprasubduction zone (SSZ) affinity Cr‐spinel is in the lower and middle Sachun Formation. These data indicate that obduction occurred before deposition of the upper Maastrichtian‐lower Paleocene Sachun Formation and developed in an intra‐oceanic setting rather than an Arabia‐Eurasia collision setting. Abundant continental‐arc affinity detrital zircon with 180–160 Ma and 50–27 Ma age‐probability peaks and varied ɛHf(t) values are present in the upper Oligocene‐lower Miocene Razak and Agha Jari formations, indicating sedimentary overlap with Eurasia. SSZ‐affinity Cr‐spinel in all samples indicates that ophiolitic rocks were a continual source of detritus in the foreland basin since Paleocene. The depositional age of the basal Razak Formation is between 25.7 and 21.5 Ma. Therefore, we interpret that collision between Arabia and Eurasia must have been initiated before deposition of the Razak Formation.