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This paper aims to update our understanding of the carbon cycle in the Himalayas, the most intense collisional orogeny globally, by providing new insight into its impact on Cenozoic climate cooling through the use of isotopic variations in both organic and inorganic carbon and an isotopic mass balance model. Our results from 20 selected hot springs show that the relative contributions of dissolved carbon from the mantle, metamorphic decarbonization, aqueous dissolution, and soil organic matter are approximately 2%, 82%, 6%, and 10%, respectively. Approximately 87% ± 5% of CO2 generated in the deep crust precipitates as calcite, while approximately 5.5% ± 1% of this carbon is converted to biomass through microbial chemosynthesis at depths less than 2 km. Our random forests approach yielded a metamorphic carbon flux from the entire Himalayan orogenic belt of approximately 2.7 ∼ 4.5 × 1012 mol/yr. The minor CO2 released into the atmosphere (2.5 ∼ 4.2 × 1011 mol/yr) is comparable to the carbon consumption driven by Himalayan weathering. This paper provides new insights into deep carbon cycling, notably that approximately 93% of deeply sourced carbon is trapped in the shallow crust, rendering orogenic processes carbon neutral and possibly acting as one of the major triggers of long‐term climate cooling in the Cenozoic. Plain Language Summary: Large‐scale deep metamorphic decarbonization and CO2 release into the atmosphere during continental collision orogenesis worldwide have had significant impacts on Cenozoic global climate change. However, the carbon sources and sinks and the mechanisms underlying their impacts on climate change are not fully understood. This paper reports the chemistry of aqueous solutions, carbon isotopic compositions of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC), and helium and carbon isotopic compositions of free gases from hot springs in southern Tibet. The carbon isotope fractionation model between gas and aqueous solutions revealed that the carbon released from depth underwent six different stages. Based on the random forests machine learning algorithm, we estimated the metamorphic carbon flux across the Himalayan orogenic belt. Furthermore, only a small fraction (7%) of deep carbon is eventually released into the atmosphere, and this volume is the same magnitude as the amount of carbon absorbed by silicate weathering on the Tibetan Plateau. This paper emphasizes that the carbon sequestration process in the upper crust may have resulted in nearly carbon‐neutral geological bodies in the Himalayan orogenic belt, thus playing a critical role in Cenozoic climate cooling. Key Points: Approximately 87% of deeply sourced carbon precipitates as calcite, while approximately 5.5% is sequestered as biomass in the shallow crustThe carbon flux across the Himalayan orogenic belt was estimated by the random forests approachCrustal thickening has attenuated long‐term deep carbon emissions from the Himalayas [ABSTRACT FROM AUTHOR]

Piper motuoense X.W.Qin, F.Su & C.Y.Hao, a new species of Piperaceae from Xizang, China, is described and illustrated in this paper. The new species resembles P. yinkiangense and P. anisotis, but it can be readily distinguished from the compared species by several characteristics. Gonophyll leaves are chartaceous and the leaf secondary vein count is 7–9, with the outermost pair being very weak when there are nine veins. Additionally, the apical pair arises 2–4 cm above the base and the leaf base is asymmetrical, with bilateral petioles that cling and heal together. Pistillate floral bracts are sessile, with 3, 4 or 5 stigmas. The description of the new species includes photographs, detailed descriptions, notes on etymology, distribution and habitat, as well as comparisons with morphologically similar species. [ABSTRACT FROM AUTHOR]

With the northward subduction and final closure of the Neo-Tethyan oceanic crust, the Indian and Eurasian plates finally collided together and underwent a strong collision orogenic event, resulting in large-scale crust–mantle magmatic interactions. In order to clarify the controversies about tectono-magmatic activities after the Indian–Eurasian continental collision, we report the newly dated Eocene Qiongduojiang gabbro explored in the Tethyan–Himalaya belt, southern Tibet. LA-ICP-MS zircon U-Pb dating shows that the crystallization age of the Qiongduojiang gabbro is 46.1 ± 1.7 Ma. The whole-rock major and trace elements, as well as Rb-Sr, Sm-Nd, and Pb isotopic data results, show that the Qiongduojiang gabbro is apparently depleted in Nd isotopes, is enriched in Pb isotopes, and has maintained a consistent 87Sr/86Sr(t) value. This paper argues that the E-MORB-like Qiongduojiang gabbro originated from asthenosphere upwelling caused by slab breakoff of the Neo-Tethyan oceanic plate. This event caused large-scale magmatic activities, a magmatic mixing process between ancient crust and deep mantle, and wild distribution of Eocene Gangdese plutons along the Yarlung–Tsangpo Suture Zone, and it rendered the subduction-modified Tibetan lithosphere fertile from the Gangdese porphyry Cu deposits. [ABSTRACT FROM AUTHOR]

Earthquake moment tensors and centroid locations in the catalogue of the Global CMT (gCMT) project, formerly the Harvard CMT project, have become an essential resource for studying active global tectonics, used by many solid-Earth researchers. The catalogue's quality, long duration (1976–present), ease of access and global coverage of earthquakes larger than about Mw 5.5 have transformed our ability to study regional patterns of earthquake locations and focal mechanisms. It also allows researchers to easily identify earthquakes with anomalous mechanisms and depths that stand out from the global or regional patterns, some of which require us to look more closely at accepted interpretations of geodynamics, tectonics or rheology. But, as in all catalogues that are, to some extent and necessarily, produced in a semi-routine fashion, the catalogue may contain anomalies that are in fact errors. Thus, before re-assessing geodynamic, tectonic or rheological understanding on the basis of anomalous earthquake locations or mechanisms in the gCMT catalogue, it is first prudent to check those anomalies are real. The purpose of this paper is to illustrate that necessity in the eastern Himalayas and SE Tibet, where two earthquakes that would otherwise require a radical revision of current geodynamic understanding are shown, in fact, to have gCMT depths (and, in one case, also focal mechanism) that are incorrect. [ABSTRACT FROM AUTHOR]

Based on the botanical explorations in Eastern Himalaya region of Xizang in China during the period 2020 to 2021, seven orchid species, Bulbophyllum gamblei, B. trongsaense, Dendrolirium ferrugineum, Taeniophyllum javanicum, Nervilia macroglossa, Trachoma rhopalorrhachis and Uncifera lancifolia, are reported as new records for China. Trachoma Garay is a newly recorded genus in China. Detailed descriptions and photographic illustrations of each species are provided in this paper to facilitate identification. Additionally, B. xizangense has been revised as a synonym for B. linzhiense. Further, a new combination is made in accordance with current orchid taxonomy, Dendrolirium pachyphylla (≡Pinalia pachyphylla). [ABSTRACT FROM AUTHOR]

The India–Asia collision zone is the archetype to calibrate geological responses to continent–continent collision, but hosts a paradox: there is no orogen-wide geological record of oceanic subduction after initial collision around 60–55 Ma, yet thousands of kilometers of post-collisional subduction occurred before the arrival of unsubductable continental lithosphere that currently horizontally underlies Tibet. Kinematically restoring incipient horizontal underthrusting accurately predicts geologically estimated diachronous slab break-off, unlocking the Miocene of Himalaya–Tibet as a natural laboratory for unsubductable lithosphere convergence. Additionally, three endmember paleogeographic scenarios exist with different predictions for the nature of post-collisional subducted lithosphere but each is defended and challenged based on similar data types. This paper attempts at breaking through this impasse by identifying how the three paleogeographic scenarios each challenge paradigms in geodynamics, orogenesis, magmatism or paleogeographic reconstruction and identify opportunities for methodological advances in paleomagnetism, sediment provenance analysis, and seismology to conclusively constrain Greater Indian paleogeography. [ABSTRACT FROM AUTHOR]

Although progress has been made in defining and explaining the temporal and spatial distributions of Neo‐Tethyan magmatism in the Tibet–Himalaya region, the correlation of magmatic suites in the SE Tibetan Plateau remains poorly constrained. This paper reports zircon U–Pb dating, geochemistry, and Sr–Nd isotope compositions of a concealed gabbroic unit (coverage area of >6.0 km2) in the southern Lancangjiang tectonic zone, western Yunnan, SW China. Zircon 206Pb/238U ages of 143–133 Ma indicate that the unit formed during the Early Cretaceous (ca. 139.7 Ma). The gabbro samples have variable MgO (7.88–16.1 wt%; Mg# = 58–74) and relatively low TiO2 (0.76–1.24 wt%) and total‐alkali (K2O + Na2O = 2.61–4.06 wt%) contents. The samples exhibit weakly fractionated rare earth element (REE) patterns with slight depletion in light REEs and negligible Eu anomalies. In a primitive‐mantle‐normalized element‐variation diagram, the gabbros, display variable enrichment in large‐ion lithophile elements and relatively flat patterns of high‐field‐strength elements. Initial 87Sr/86Sr ratios of 0.7079 to 0.7142 and relatively depleted εNd(t) values of +3.96 to +4.84 are similar to those of the mantle source of back‐arc basin basalts (BABBs) in the central Lhasa Block and mid‐ocean ridge basalt in the Indus–Tsangpo Suture Zone. These various characteristics suggest that the gabbroic unit was derived from a shallow and depleted mantle source by relatively high‐degree partial melting in the spinel stability field. The parental magma underwent slight crustal contamination, as well as fractional crystallization of clinopyroxene. The studied gabbros have distinct BABB‐type geochemical affinities similar to those of the Okinawa BABB. Combining our data with the coeval occurrence of a continental rift basin (the Simao–Lanping Basin) leads us to suggest the existence of a back‐arc rifting setting in the SE Tibetan Plateau during the Jurassic–Cretaceous. This setting can also be geochronologically and genetically correlated to the back‐arc basin developed within the Lhasa Block. These settings and constituent characteristics formed as a result of Neo‐Tethyan oceanic slab subduction during the late Mesozoic. [ABSTRACT FROM AUTHOR]

More than 200 years since its initial exploration, Zanda Basin, a high-elevation (3,800–4,500 m above sea), intermountain basin at the foothills of the Himalaya, is the site to some of the earliest fossil discoveries, including the holotype of extinct Tibetan antelope, Qurliqnoria hundesiensis. These fossils also hold the record, in 1823, as the first vertebrate fossils from Tibet in the scientific literature. Unfortunately, these tantalising early records have become all but forgotten for more than 100 years due to a lack of information about their localities. Our recent explorations in the 2000s revive the interests in Zanda Basin and establish a unique Zanda mammal assemblage important in the evolution of Tibetan Neogene mammals. In this paper, we retrace the expedition routes by early explorers and attempt to establish, to the extent possible, the type locality of two key mammals in the Zanda fauna: Q. hundesiensis and Hipparion (Plesiohipparion) zandaense. We highlight the pivotal role Zanda fossil mammals play in the early discourse of mountain building, climate change, and mammal adaptation in high Himalaya, more than a hundred years before Chinese palaeontologists made a similar argument upon the discovery of three-toed horses, in the 1980s, at different basins in Tibet. [ABSTRACT FROM AUTHOR]

Second- and third-order gravitational potential derivatives can be employed for the determination of the medium- and high-frequency parts of the Earth's gravity field. Due to the Gravity field and steady-state Ocean Circulation Explorer mission, second-order derivatives (SOD) in particular, express currently observed functionals of high accuracy and global coverage. Third-order derivatives (TOD), or gravitational curvature data, provide significant gravity field information when applied regionally. The absence of directly observed TOD data underlines the importance of investigating the relationship between SOD and TOD. This paper discusses the combination of simulated SOD in order to obtain TOD at satellite altitude by applying the spectral combination method. For the determination of TOD integral equations are developed that utilize SOD data at satellite altitude, thus extending the well-known Meissl spectral scheme. The performance of the derived mathematical models is investigated numerically for the test area of Himalayas and the Tibet region. Two different TOD computational strategies are examined. First, we define a deterministic approach that recovers TOD data from noise-free simulated SOD data. Results show that retrieved TOD data at satellite level reach an agreement of the level of 1 × 10−17 m−1s−2 when compared with the true TOD data. Secondly, we propose a new mathematical model based on the spectral combination of integral relations and noisy SOD data with Gaussian noise for recovering TOD. Integral estimators of biased and unbiased types are examined in the cases of SOD data at satellite altitude. The used vertical SOD components show differences between the recovered and true vertical TOD components in the order of 1 × 10−17 m−1s−2 in magnitude, proving the vertical–vertical component of SOD as the best for validating purposes. [ABSTRACT FROM AUTHOR]

Himalayan leucogranites are widely distributed in the North Himalayan gneiss dome (NHGD) and at the top of the Greater Himalayan Crystalline Complex (GHC) and are generally controlled by detachment faults. The ages of these prekinematic, synkinematic, and postkinematic leucogranites can be used to limit the activity of detachment structures (such as the South Tibetan Detachment System, STDS). Research on the STDS activity time in the eastern Himalayas is relatively sparse. In this study, the zircon and monazite U–Th–Pb geochronology of synkinematic and postkinematic leucogranites, which are affected by the STDS and NHGD, in four areas (Lhozhag, Kuju, Xiaozhan, and Cuonadong) in Shannan City, Tibet, China, was measured. The results show that the oldest synkinematic two‐mica granite from Lhozhag, which is affected by the STDS, is 24–25 Ma, so the time of STDS activity is at or slightly earlier than 25 Ma. The youngest synkinematic leucogranite is the garnet‐bearing muscovite granite in Cuonadong at 18.4 Ma. The oldest undeformed postkinematic leucogranite (not affected by the STDS) is the muscovite granite in Xiaozhan at 17.4 Ma. Therefore, the end of STDS activity can be limited to 18.4–17.4 Ma. The STDS includes three forms: detachment fault in the NHGD (northern extension of the STDS), the inner STDS between the GHC and Tethyan Himalayan Sequence, and the outer STDS at the bottoms of synformal klippes. In this paper, the active time limits of the above three kinds of detachment zones are comprehensively summarized. Based on this work, the northward extension (ductile deformation) time of the STDS in the region is considered to be 28–17 Ma. The exhumation of the GHC is mainly controlled by in‐sequence shearing: first, the South Tibet Thrust system (predecessor of the STDS) at the top of the GHC thrust southward at 45–28 Ma, then the High Himalayan Discontinuity fault in the middle of the GHC forms south‐vergent ductile thrusts at 28–17 Ma, and finally, the Main Central Thrust at the bottom of the GHC thrust southward at 17–9 Ma. [ABSTRACT FROM AUTHOR]

This paper explores the traditions of Himalayan book-making from manuscript through xylograph printing. Current projects involving scanning and digitization of sacred texts, developments of digital Tibetan fonts, print on demand texts in pothi format, and new Tibetan libraries and preservation projects show the rich and varied history of the book in Tibet. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports that three earthquake sequence occurred in 1996 (m b 5.9), 1998 (m b 5.8) and 2004–2005 (m b 6.2, 6.3) were observed preceding the anomalous seismic activity. The nature of anomalous seismicity associated with these earthquakes have been investigated considering earthquakes with m b ⩾4.1 (cut off magnitude for this region) in four seismic episodes (NAGM): normal/background (N); anomalous/swarm (A); precursory gap (G) and mainshock sequence (M), respectively. It is established here that the anomalous seismicity/swarm patterns follow episodes of relatively very low seismic activity and it is an important finding to visualize that an area might be preparing for the occurrence of a forthcoming mainshock. Such anomalous seismic patterns were observed prior to medium size mainshocks that occurred from 1963 to 2006 in South Central Tibet (SCT) region to the north of Central Himalaya. From these observations it may be inferred here that the patterns of anomalous seismicity/earthquake swarms may be considered as an important parameter (precursor) for the forecasting of long-range earthquake hazards in the SCT region. In consideration of spatial and the temporal clustering of swarm events that are prominent and confined in a vertical column of 10–45km, enabled to locate potential area enclosed by 29.6–30.1°N and 87.8–88.1°E where future earthquake of magnitude 6.0 and above in the depth range 25±15km may be seated. In view of this multi-parameter short term precursory signals monitoring is suggested for the delineated preparatory area to make earthquake prediction/forecasting programs more meaningful. [Copyright &y& Elsevier]

Abstract: The provenance of upper Cretaceous strata in the Tethys Himalaya provides critical constraints on the closure time of the Neo-Tethys Ocean and the initial India–Asia collision. This paper reports detailed petrographic studies, in-situ detrital zircon U–Pb ages and Lu–Hf isotopic analyses, whole rock Nd-isotopes, and Cr–spinel electronic microprobe data from upper Cretaceous clastic sedimentary rocks of the Tethys Himalaya near Gyangze, southern Tibet. The Berriasian–Coniacian Jiabula Formation consists of black mudstone, chert and minor quartz arenite, and is dominated by detrital zircons with Archean–Cambrian U–Pb ages which were most likely derived from the Indian continent. Overlying conformably is the Santonian–Maastrichtian Chuangde Formation, which consists of red shale, limestone and chert. The Chuangde Formation is in turn overlain by the late Maastrichtian–late Paleocene Zongzhuo Formation, which is composed of black mudstone and lithic sandstone enclosing various olistoliths of sandstone, limestone and chert. The Rilang conglomerate is a lens which is located within the upper part of the Zongzhuo Formation and consists of an upward-thinning and fining succession of volcanic conglomerate, sandstone and black mudstone. The Zongzhuo Formation and the Rilang conglomerate record an abrupt influx of Cretaceous zircon grains with juvenile Hf isotopic compositions, arc-related Cr–spinels and positive εNd(0) sediments, suggesting an arc and suture-zone provenance. The change in provenance of upper Cretaceous strata from the southern Indian continent to a northern arc and suture zone is attributed to either (1) initial collision between the Indian plate and Lhasa terrane, or (2) initial collision between the Indian plate and an intra-oceanic arc. We prefer option (1) that the initiation of India–Asia collision occurred during Maastrichtian (~70–65Ma). [Copyright &y& Elsevier]

The Eastern Karakoram is a remote and under studied region of Ladakh in the northwestern Himalaya. The geology of the area provides insight into the evolution of the south Asian margin since the Paleozoic and is dominated structurally by the Karakoram fault, an ∼800 km long dextral strike-slip fault that bounds western Tibet. In this paper, a 1:250,000 geological map is presented based upon fieldwork and interpretation of satellite imagery. An overview of the geology of the Eastern Karakoram is also presented and includes a discussion of the architecture and kinematics of the central segment of the Karakoram fault. The construction of the map has aided our understanding of the initiation and evolution of the Karakoram fault and of the geology of the south Asian margin in this region. [ABSTRACT FROM AUTHOR]

Frequency contents of a seismic trace, varying with time carry information about the properties of the subsurface reflectivity sequence. In this paper, frequency transition technique for the reflection sequence analysis of the seismic data has been presented. The technique is the extension of the frequency attributes representation of seismic data. Frequency attributes, separate display of the seismic time amplitude maps, are computed with complex trace analysis. Moderate and sharp frequency variations are found all over the traces with time. Sharp frequency variations and the time of appearance are termed as transition frequency and transition time respectively. Transition-factor (T-factor) has delineated for marking the sharp frequency variation in the time frequency plots. T-factor differentiates high, moderate and transition frequency variations. The technique is explained with examples and has been applied for studying the reflection sequences of the INDEPTH seismic data. The proposed seismic reflection analysis can be used to identify the strata by sequence stratifying the seismic data. [ABSTRACT FROM AUTHOR]

The Himalayan range is one of the most tectonically active mountain ranges on Earth. The Jilong Valley is a deeply-dissected canyon in the Chinese Himalayas in Tibet, and in this valley, landslide hazard and risk have increased significantly in response to active crustal movements, intense rainfall and ever-increasing human interference. Landslide susceptibility assessment in the valley is fundamental for risk mitigation and to inform land use and planning but remains a challenge owing to the inaccessible high altitude and incomplete landslide inventory. In addition, because of sustained glacial erosion, weathering, and denudation, there is considerable uncertainty in the use of remote sensing interpretation of landslides in high-altitude terrain. In this paper, therefore, a systematic approach for landslide susceptibility assessment is proposed, combining the interpretations from remotely sensed dataset and both heuristic and statistical susceptibility models to overcome the problem of the limited spatial coverage of landslide data and uncertainty in landslide interpretation. The main steps include: 1) landslide field investigation and interpretation and the compilation of a preliminary landslide inventory, including certain and probable landslides, 2) knowledge-driven identification of landslide-prone areas based on the heuristic model, 3) classification and quantification of the uncertainty of probable landslides through heuristic landslide-prone areas mapping and the production of a revised landslide inventory, and 4) data-driven susceptibility assessment using a statistical model. In the statistical model, the landslide samples have multivalent dependent variables between 0 and 1. Therefore, a multinomial statistical classifier and multiclass Receiver Operation Characteristic curves are needed for model calibration and validation. The statistical susceptibility mapping showed good performance in the study area, with an average AUC of 0.867, which is a significant improvement over the heuristic model. The methodology presented can be used for landslide susceptibility mapping in data-scarce environments, not only in the Himalayan region but also in other mountainous areas where there is a lack of data on past landslide occurrences. • A method proposed for landslide susceptibility with incomplete landslide inventory. • Uncertain landslide sample interpreted from remote sensing data is considered. • Landslide susceptibility is assessed with multinomial logistic regression model. [ABSTRACT FROM AUTHOR]