Download or read book The Sedimentary and Tectonic Evolution of the Nam Co Basin Tibetan Plateau Since the Middle Pleistocene written by Nora Schulze and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancing climate change threatens the supply of water and sediment resources provided by the Tibetan Plateau. This could expose one-fifth of the global population to significant societal, ecological, and economic adversity. Accurate climate models based on data of past climatic changes are, thus, essential to prepare best for the effects of climate change. A promising and yet undeveloped climate archive is Nam Co (Co= Tibetan for Lake). This doctoral thesis contributes substantially to the sedimentary, climatic, and tectonic understanding of Nam Co. It sets an essential basis for the evaluation of Nam Co's potential as a high-resolution and extensive climate archive and the selection of suitable drill sites for the ICDP drilling campaign 'NamCore'. In detail, this thesis investigates 1) spatial sedimentary structures, distributional and depositional processes, and lake-level variations of the last 20.5 kyrs, 2) long-term climate-driven lake-level variations throughout the last 700 kyrs, correlated to the shift of the Asian summer monsoon, and 3) the transtensional tectonic setting of Nam Co, resulting in a novel perception of the tectonic extension in southern Tibet since the Middle Pleistocene. High-resolution hydro-acoustic data, comprising sediment echo sounder (SES) and multichannel reflection seismic (MCS) data, build the basis of the presented studies.
Download or read book Growth and Collapse of the Tibetan Plateau written by Richard Gloaguen and published by Geological Society of London. This book was released on 2011 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite agreement on first-order features and mechanisms, critical aspects of the origin and evolution of the Tibetan Plateau, such as the exact timing and nature of collision, the initiation of plateau uplift, and the evolution of its height and width, are disputed, untested or unknown. This book gathers papers dealing with the growth and collapse of the Tibetan Plateau. The timing, the underlying mechanisms, their interactions and the induced surface shaping, contributing to the Tibetan Plateau evolution are tightly linked via coupled and feedback processes. We present interdisciplinary contributions allowing insight into the complex interactions between lithospheric dynamics, topography building, erosion, hydrological processes and atmospheric coupling. The book is structured in four parts: early processes in the plateau formation; recent growth of the Tibetan Plateau; mechanisms of plateau growth; and plateau uplift, surface processes and the monsoon.
Download or read book Tectonic and Climatic Evolution of the Central northern Tibetan Plateau written by Lin Li and published by . This book was released on 2016 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The uplift history of the Tibetan Plateau serves as key evidence for understanding the dynamic models that build the Plateau and its influence on Cenozoic climate change of East Asia. This dissertation contributes to our knowledge for the growth history of the central and northern Tibetan Plateau through sedimentary analysis of basin sequences, and stable isotope analysis of carbonate rocks and modern surface waters. Field work in the Hoh Xil basin of central Tibet, including facies analysis, paleocurrent reconstruction, detrital zircon provenance analysis, and stable isotope analysis, suggests that a unified Hoh Xil basin, including both the east and west sub-basins, experienced a transition from pre-India-Asia collision foreland basin to post-collision hinterland basin setting at around 50 Ma. The Qiangtang terrane, serving as the main source for sediments deposited in the Hoh Xil basin, experienced significant topographic growth during the Cretaceous time. Far field deformation in the Hoh Xil basin was initiated shortly after India-Asia collision; contractional deformation and concomitant filling of the Hoh Xil hinterland basin provides clues for outward and upward growth of the Tibetan Plateau during Cenozoic time. Work in the western Qaidam basin provides new lithostratigraphy and carbonate stable isotope data that records early-middle Miocene topographic growth of the northern Tibetan Plateau. A hydrological change from restricted sub-basin to open marginal basin around 20 Ma was probably caused by late Oligocene-early Miocene tectonic activity around the Qaidam basinches A major topographic growth in the northern Tibetan Plateau is inferred around 15 Ma based on a negative shift in oxygen isotopic values, sedimentary facies changes from marginal lacustrine to fluvial, and an increase in sedimentation rate. A 13-12 Ma aridification event that was observed over a large area of the northern Plateau was likely caused by continued topographic growth to a critical point to block moisture from entering the northern Tibetan Plateau. To understand the caveats of stable isotope-based paleoaltimetry in the central and northern Tibetan Plateau, a comprehensive data set of 1,315 river water samples (450 newly collected) was compiled. With this large data set, a consistently assumed, but not well-documented prerequisite is demonstrated that river waters are a good substitute for isotopic studies of precipitation on the high Tibetan Plateau on the mean annual scale. The spatial variations of [delta]18O/[delta]D and d-excess values in the plateau margins can be modeled as a Rayleigh distillation process, on which stable isotope-based paleoaltimetry is based. On the contrary, the isotopic values of meteoric waters in the interior of the plateau are controlled by the combined effects of mixing of different moisture sources, contribution of recycled moisture from local surface water evaporation, and sub-cloud evaporation. A Rayleigh distillation model modified by sub-cloud evaporation is provided to simulate the isotopic variations in the western Plateau. This new understanding indicates that stable isotope-based paleoaltimetry is most reliable in the southern margins of the Plateau, and increasingly unreliable toward the northern Plateau. In addition, the contour maps of modern isotopic variations of meteoric waters across the whole Tibetan Plateau also provide validation criteria for isotopic simulations using general circulation models"--Pages v-vi.
Download or read book Uplift Mechanisms and the History of the Tibetan Plateau written by Junsheng Nie and published by Geological Society of America. This book was released on 2014 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nothing provided
Download or read book Late Quaternary Hydrological Paleoenvironmental and Geomorphological Processes in the Tibetan Plateau and Its Adjacent Areas written by Xiangjun Liu and published by Frontiers Media SA. This book was released on 2022-02-23 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sedimentary Evolution of the Qinghai Tibetan Plateau in Cenozoic and its Response to the Uplift of the Plateau written by Kexin Zhang and published by Springer. This book was released on 2018-11-10 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on highly detailed field investigations and test data from research on 98 different remnant basins, tectonic settings and lithostratigraphic sequences, this book describes the 4-stage evolution of the tectonic lithofacies paleogeography of the Qinghai-Tibetan Plateau, including Paleocene-Eocene, Oligocene, Miocene and Pliocene. It also discusses the contact relationship between the strata, the tectonic-lithofacies paleogeography evolution in the Cenozoic and their response to the tectonic uplift of the plateau. The continuous uplift and intensive intra-continental deformation during each turning point in the plateau divided the originally large sedimentary basins into numerous smaller ones filled with shrank of lacustrine-facies deposition and increased boulderstone accumulation, which indicates a response to the overall uplift of the plateau. Five major uplift events, which happened in 58-53 Ma, 45-30 Ma, 25-20 Ma, 13-7 Ma and since 5 Ma, respectively were identified. The paleogeographic configurations of the Tibetan Plateau turned over during the late Miocene, with high contours in the east during the pre-Miocene switching to the west after the Late Miocene
Download or read book Mountain Geoecology and Sustainable Development of the Tibetan Plateau written by Du Zheng and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intense uplift of the Tibetan Plateau in Late Cenozoic Era is one of the most important events in geological history of the Earth. The plateau offers an ideal region for studying of lithospheric formation and evolution, probing into the mechanism of crustal movement, and understanding of changes in environments and geo-ecosystems in Asia. Intense uplift ofthe plateau resulted in drastic changes of natural environment and apparent regional differentiation on the plateau proper and neighboring regions. The plateau therefore becomes a sensitive area of climate change in Asian monsoon region, which is closely related to the global change. As a special physical unit, its ecosystems occupy a prominent position in the world. Due to its extremely high elevation and great extent, natural types and characteristics of physical landscapes on the plateau are quite different from those in lowlands at comparable latitudes, and environments are also different from those in high latitudinal zones. Consequently, the Tibetan Plateau has been classified as one of three giant physical regions in China and considered as a unique unit on Earth. Scientific surveys and expeditions to the Tibetan Plateau on large scale began from 1950's. Amongst them, a number of comprehensive scientific expeditions to the Xizang (Tibet) Autonomous Region, Hengduan Mts. areas, Karakorum and Kunlun Mts. regions, as well as the Hoh Xii Mts. areas, have been successively carried out by the Integrated Scientific Expedition to Tibetan Plateau, sponsored by Chinese Academy of Sciences since 1973.
Download or read book Lake Records of Environmental and Climate Change on the Tibetan Plateau written by Zhang Chengjun and published by Frontiers Media SA. This book was released on 2022-11-07 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crust Mantle Thermal Structure and Tectonothermal Evolution of the Tibetan Plateau written by Xianjie Shen and published by VSP. This book was released on 1996-12 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph deals with systematic studies of all relevant thermal aspects of the Tibetan Plateau, including terrestrial heat flow measures, distribution pattern of observed heat flow along a N-S profile, crust-mantle thermal structure, and North-Middle-South triple heterogeneity across the whole plateau. Main emphasis has been put on the close correlation between thermal and comprehensive geophysical fields and the intrinsic genetic linkage between tectonic deformation of terranes and thereby induced deep-seated and superficial theral activities and responses. This new approach, in combination with available geoscientific research results, has led to a synthetic idea of integrated tectonothermal evolution of the Tibetan Plateau.
Download or read book Source to Sine Relations Between the Qaidam Basin Tibet and the Surrounding Mountains written by Feng Cheng and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Qaidam basin, located within the northern Tibetan plateau, is the deepest intracontinental basin, yet located in the highest plateau with the thickest continental crust. Understanding how this peculiar basin developed has broad implications for the Tibetan geology in particular and for continental tectonics in general. Many approaches have been used to decipher the tectonic and topographic history of that region, however, the initial topography of the area now represented by the northern Tibetan plateau, as well as the early stages of development of the present day topography remain poorly constrained and highly debated. In order to better understand the Cenozoic evolution of the Qaidam basin and its surrounding regions (including Eastern Kunlun Range to the south, Altyn Tagh Range to the northwest, and Qilian Shan to the northeast), four critical issues are addressed in this thesis: 1) the Cenozoic joint tectonic evolution of the Qaidam basin and the Eastern Kunlun Range; 2) the interplay between the sedimentation within the Qaidam basin and the active tectonics within the Altyn Tagh Range; 3) a quantitative estimate of the lateral extrusion along the Altyn Tagh Fault-Qilian Shan tectonic system; 4) the nature and classification of the Qaidam basin. I suggest that the SW Qaidam basin has been bordered by a series of strike-slip faults to the south since the Early Miocene, rather than, as previously suggested by a continuous northward or southward thrusting system. Based on U-Pb dating (LA-ICP-MS) of detrital zircons collected from 4 sections (Paleocene to Holocene) within the southwestern Qaidam basin combined with provenance analysis and new seismic profile interpretation, I demonstrated that the Eastern Kunlun Range was already exhumed prior to the Paleocene. I show that the Qaidam basin was widening southward during thet early Cenozoic period (Paleocene to Oligocene). From Oligocene the relief of the Eastern Kunlun and Altyn Tagh ranges increased, leading to isolation and narrowing of the Qaidam basin from Miocene to the present. Along the northern edge of the basin, I identified the Tula-Huatugou and Anxi-Eboliang regions as residual parts of the original Qaidam basin. I suggest that the Altyn Tagh Fault has experienced a total of ~360 km of displacement since its Early Eocene initiation. Based on this ~360 km northeastward migration of the relatively rigid Qaidam block along the Altyn Tagh Fault and 3D isovolumetric balance of the crustal deformation within the Altyn Tagh Fault - Qilian Shan system, I demonstrate that 250 ± 28 km (43.8~49.4 %) of N20E directed crustal shortening and an additional ~250 to ~370 km of eastward motion of the Qilian Shan crust must be accounted for by strike-slip faulting in the Qilian Shan and crustal thickening in the Qinling area, as well as extension in the adjoining North China block graben systems.
Download or read book Stratigraphy and Tectonic Implications of Upper Cretaceous Rocks in the Powder River Basin Northeastern Wyoming and Southeastern Montana written by Edward Allen Merewether and published by . This book was released on 1996 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multidisciplinary approach to research studies fo sedimentary rocks and their constituents and the evolution of sedimentary basins--both ancient and modern.
Download or read book The Evolution of the Northeastern Margin of the Tibetan Plateau written by Brian G. Hough and published by . This book was released on 2010 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Tracking climate change through the use of paleoclimate proxies has the potential to reveal the spatial and temporal evolution of orogens and their associated plateaux. The development of topography associated with the Cenozoic evolution of the Tibetan plateau is coupled to climate, and feedbacks between climate and tectonics occur at all scales. Because climate changes resulting from topographic growth should scale with the amount, extent, and timing of surface uplift, this dissertation documents temporal and spatial changes in paleoclimate of the northeastern margin of the Tibetan plateau since ~30 Ma, in order to delineate when the modern climate pattern was achieved and, by inference, when the Tibetan plateau reached its current dimensions. Sedimentation in basins adjacent to the plateau margin likely began in a foreland basin setting that was later segmented by the growth of basin-bounding structures presumably during upward and outward growth of the plateau. This study focuses on a number of sub-basins in northeast Tibet, including Guide, Jian Zha, Xunhua, Tong Ren, Hualong, and Linxia, that span up to 30 myr in age and range up to 3 km thick. New lithologic, magnetostratigraphic, and stable isotope records from these basins suggest that topography began to develop in the Eocene and continued through the late Miocene before jumping ~100 km outward at ~8 Ma to the Liupan Shan and Haiyuan faults. Perturbations to local climate patterns resulted from the evolution of local topography and basin segmentation. These patterns are tracked through comparison of stable isotope compositions of calcareous basin fill materials. Similarity of isotopic compositions is interpreted to reflect the presence of integrated basins whereas distinct isotopic compositions reflect unique basin hydrologies. Within the study area, changes in isotope trends are observed throughout each record indicating the influence of local climate conditions on isotopic values. Synchronous isotope changes in multiple records are observed at 18.5, 16.3, and 9.4 Ma possibly corresponding with changes in regional scale climate. A time-transgressive trend of Miocene aridification in the lee of growing topography along the plateau's northeast margin is roughly coeval with and spatially consistent with the blocking of vapor transport by west-to-east growth of eastern Tibet. Modern rainfall data collected from 2007-2009 across the Tibetan plateau's northeastern margin show seasonal trends related to changes in air temperature and elevation, but not precipitation amount or relative humidity. To assess the spatial variability and thus the degree to which any one monitoring station is representative of a large geographic region, climate variables and rainwater isotope data from seven collection stations located across the study area were compared to each other and to the Global Network of Isotopes in Precipitation (GNIP) station data from Lanzhou. Annual mean and long-term mean isotope compositions of rainfall match each other and those from the GNIP station in Lanzhou suggesting that the long-term values for any one station are representative over relatively large regions. Trends in [delta]8O and d-excess indicate that source regions for summertime precipitation in northeast Tibet are consistent with increased soil moistening and local recycling of water vapor. When carbonates derived from modern rainfall are compared to time integrated paleo-carbonate samples, no significant change in regional climate are evident since at least 3-4 Ma. The results of this thesis demonstrate that changes in local climate are related to the onset of local deformation and that deformation and associated basin segmentation in NE Tibet initiated prior to uplift of eastern Tibet. However, the timing of regional-scale climate change, highlighted by a west-to-east pattern of aridification in northern and northeastern Tibet, is consistent with the systematic displacement of vapor pathways around a progressively eastward uplifting eastern Tibetan plateau. Once established, the upwind climate regime, and by inference the topographic framework of northeast Tibet, has remained stable since ~8 Ma."--Leaves v-vii.
Download or read book Indian Plate and Its Epic Voyage from Gondwana to Asia written by Sankar Chatterjee and published by Geological Society of America. This book was released on 2017-07-21 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: \The fossil history of animal life in India is central to our understanding of the tectonic evolution of Gondwana, dispersal of India, its northward journey, and its collision with Asia. This book provides the only detailed overview of the paleobiogeographic, tectonic, and paleoclimatic evolution of the Indian plate from Gondwana to Asia. This thorough, up-to-date volume is a must-have reference for researchers and students in Indian geology, paleontology, plate tectonics, and collision of continents.
Download or read book Neogene Stratigraphic Relationships Within the Nam Con Son Basin Offshore Vietnam Resulting from Tectonics Eustasy and Sediment Flux written by Christine M. Wright and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The South China Sea is a region of significant importance in terms of the records of SE Asian tectonics, including Tibetan Plateau uplift, and the onset and evolution of the East Asian monsoon. The Mekong River has been a dominant sediment source since at least late Miocene time and has headwaters on the eastern Tibetan Plateau. Understanding the Pliocene to Recent stratigraphy of the paleo-Mekong Delta and associated shelf-edge deposits aids in understanding changes in accommodation, sea level, and sediment supply. This record might then be useful in interpreting the longterm history of basin evolution in the Nam Con Son Basin. Nine sequence boundaries and associated sequences are recognized along the late Miocene to latest Pleistocene shelf in the East Nam Con Son Basin. Age constraints were assigned to key stratigraphic horizons by correlating sequence boundaries with published sea level curves. Accommodation in the study area is controlled by shelf -edge compaction, rift-related thermal subsidence, non-rift-related anomalous subsidence, eustatic change, and shelf edge faulting. Two primary sources supplied sediment to the southwestern South China Sea during Pliocene to Recent time and likely include the paleo-Mekong Delta and a fluviodeltaic system originating from the Sunda Shelf, such as the Molengraaff River. Changes in thickness, area, and location of Pliocene to Recent shelf-edge delta deposits reflect changes in accommodation and sediment supply over time, as well as progradation of the shelf edge during Pliocene to Recent time and avulsion of the shelf edge delta. Anomalous subsidence of LGM shelf edge deposits is estimated at approximately 40-50 m deeper than expected. The current depth of the LGM deltaic wedge may indicate renewed rapid tectonic subsidence during the last 18,000 yrs, possible compaction effects or a combination of these.
Download or read book Tectonics of the Himalaya written by S. Mukherjee and published by Geological Society of London. This book was released on 2015-09-28 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Himalayan mountain belt, which developed during the India–Asia collision starting about 55 Ma ago, is a dramatically active orogen and it is regarded as the classic collisional orogen. It is characterized by an impressively continuous 2500 km of tectonic units, thrusts and normal faults, as well as large volumes of high-grade metamorphic rocks and granites exposed at the surface. This constitutes an invaluable field laboratory, where amazing crustal sections can be observed directly in very deep gorges. It is possible to unravel the tectonic and metamorphic evolution of litho-units, to observe the mechanisms of exhumation of deep-seated rocks and the propagation of the deformation. Himalayan tectonics has been the target of many studies from numerous international researchers over the years. In the last 15 years there has been an explosion of data and theories from both geological and geophysical perspectives. This book presents the results of integrated multidisciplinary studies, including geology, petrology, magmatism, geochemistry, geochronology and geophysics, of the structures and processes affecting the continental lithosphere. These processes and their spatial and temporal evolution have major consequences on the geometry and kinematics of the India–Eurasia collision zone.
Download or read book Tectonic Evolution of the Himalayas and Tibet written by Royal Society (Great Britain). Discussion Meeting and published by . This book was released on 1988 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Age and Tectonic Evolution of the Amdo Basement Implications for Development of the Tibetan Plateau and Gondwana Paleogeography written by Jerome Guynn and published by . This book was released on 2006 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: The elucidation of the geologic processes that led to the creation of the Tibetan Plateau, a large area of thick crust and high elevation, is a fundamental question in geology. This study provides new data and insight on the geologic history of central Tibet in the Jurassic and Cretaceous, prior to the Indo-Asian collision, as well as the Gondwanan history of the Lhasa and Qiangtang terranes of the plateau. This investigation is centered on the Bangong suture zone near the town of Amdo and I present new geochronology, thermochronology, thermobarometry and structural data of the Amdo basement, an exposure of high-grade gneisses and intrusive granitoids. Using a range of thermochronometers, I show there were two periods of cooling, one in the Middle-Late Jurassic after high-grade metamorphism and a second in the Early Cretaceous. I attribute Middle-Late Jurassic metamorphism, magmatism, and initial cooling of the Amdo basement to arc related tectonism that resulted in tectonic or sedimentary burial of the magmatic arc. I propose that a second period of cooling, nonmarine, clastic sedimment deposition and thrust faulting in the Early Cretaceous is related to the Lhasa-Qiangtang collision. The thermochronology reveals limited denudation between the Cretaceous and the present, indicating the existence of thickened crust when India collided with Asia in the early Tertiary. U-Pb geochronology of the orthogneisses and detrital zircon geochronology of metasedimentary rocks suggests that the Lhasa and Qiangtang terrane were located farther west along Gondwanan's northern margin than most reconstructions depict.
