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Differential surface uplift: Cenozoic paleoelevation history of the Tibetan Plateau

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Science China Earth Sciences 2016年第11期59卷 2105-2120页

作者： LIU XiaoHui XU Qiang DING Lin Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Science Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

The surface uplift history of the Tibetan Plateau has provided a key boundary criterion for various geological, climatic,and environmental events since the Cenozoic. The paleoelevation history of the plateau is organically associated with interactions amongst deep geodynamics, earth surface processes, and climate change. Understanding of plateau uplift history has been advanced by the development of a number of paleoaltimetries and their application to studies of the Tibetan Plateau: the paleogeomorphic scenario for the Early Eocene Tibetan Plateau is thought to include two high mountains, the ca. 4500 m Gangdese Mountains to the south, and the ca. 5000 m Qiangtang Center Watershed Mountains to the north. Between these ranges, a low-elevation basin(ca. 2500 m) is thought to have been present. The Himalayas in the southern Tibetan Plateau was close to sea level at this time,while the Hoh Xil Basin in the north reached an elevation of no more than 1500 m. Thus, the so-called "Roof of the World" Tibetan Plateau formed subsequent to the Miocene. Nevertheless,, the uplift histories of the different terranes that comprise this plateau currently remain unclear, which constrains the uplift history reconstruction of the entire Tibetan Plateau. Additional paleoelevation data from different areas, obtained using multi-paleoaltimeters, is required to resolve the forms and processes of Tibetan Plateau uplift and extension.

关键词： paleoelevation 微分表面高举新生代西藏的高原

Carbon and oxygen isotopic constraints on paleoclimate and paleoelevation of the southwestern Qaidam basin, northern Tibetan Plateau

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Geoscience Frontiers 2017年第5期8卷 1175-1186页

作者： Lin-Lin Li Chao-Dong Wu Chang-Fu Fan Ji-Jun Li Chang-Hao Zhang Key Laboratory of Crustal Dynamics Institute of Crustal DynamicsChina Earthquake AdministrationBeijing 100085China Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing 100871China Institute of Oil&Gas Peking UniversityBeijing 100871China MLR Key Laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China No.1 Oil Producing Plant of PetroChina Qinghai Oilfield Company Dunhuang 736202China Exploration Department PetroChina Qinghai Oilfield CompanyDunhuang 736202China

We investigate the growth of the northern Tibetan Plateau and associated climate change by applying oxygen and carbon isotopic compositions in Cenozoic strata in the southwestern Qaidam basin. The X-ray diffraction and isotopic studies reveal that the carbonate minerals are mainly authigenic and they do not preserve any evidence for detrital carbonate and diagenesis. The isotope data show large fluctuations in the δ^(18)O and δ^(13)C values in the middle-late Eocene, indicating relatively warm and seasonal dry climate.The positive correlation of the δ^(18)O and δ^(13)C values in the Oligocene and the positive shift of the δ^(13)C values from the Eocene to Oligocene suggest that the climate changed to arid in the Oligocene. However,the δ^(18) values show negative shift, which is closely related to the global cooling event. During the Miocene, the δ^(13)C values vary between-2‰ and-4‰, whereas the δ^(18)O values show continuous negative shift. The mean δ^(18) values decrease from-8.5‰, in the early Miocene to-10.0‰, in the late Miocene. The stable isotope-based paleoaltimetry results suggest that the elevation of the southwestern Qaidam basin was approximately 1500 m in the middle-late Eocene and Oligocene. Subsequently, during Miocene the crustal uplift process started and the elevation reached approximately 2000 m in the early Miocene and 2500 m in the late Miocene, which suggests large-scale growth of the northern Tibet Plateau during the Miocene.

关键词： Carbon and oxygen isotopes Northern Tibetan Plateau Qaidam basin paleoelevation

Global-scale altitude effect on leaf wax n-alkane δD values in terrestrial higher plants

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Science China Earth Sciences 2021年第5期64卷 825-834页

作者： Jinzhao LIU Zhisheng AN State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China CAS Center for Excellence in Quaternary Science and Global Change Xi'an 710061China

Numerous field studies have shown that leaf wax n-alkane δD values(δD_(n-alkane))can be used as a proxy for paleoelevation reconstruction.However,the lack of systematic global analysis of δD_(n-alkane) values with respect to altitude limits the reliability of δD_(n-alkane )values for paleoaltimetry at the global scale.In this study,we analyzed the variation of δD_(n-alkane) values with altitude in terrestrial higher plants based upon our compiled globalδDn-alkane database.The general decrease in δD_(n-alkane) values with altitude corresponds to the variation in precipitationδD(δD_(prec))with altitude,suggesting that the δD_(n-alkanevalues) effectively reflect δD_(prec) values.When eliminating the effect of latitude at the global scale,the global δD_(n-alkane)-altitude lapse rate for all species was-1.01±0.10‰(100 m)-1,while these lapse rates were-1.03±0.13‰ and-0.47±0.13‰(100 m)^(-1) for dicots and monocots,respectively.Our study reveals that it is reliable to use δD_(n-alkanevalues) to gain information about paleoelevation at the global scale,and the global δD_(n-alkane-altitude) lapse rates provide an alternative to reconstruct paleoelevation at some δD_(n-alkane)-uninvestigated areas.

关键词： Altitude Leaf wax n-alkaneδD Global scale paleoelevation

Paleoaltimetry reconstructions of the Tibetan Plateau:progress and contradictions

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National Science Review 2015年第4期2卷 417-437页

作者： Tao Deng Lin Ding Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of Sciences

Over the last two decades, many quantitative paleoaltimetry reconstructions of the Tibetan Plateau have been published, but they are still preliminary and controversial, although several approaches have been combined paleontology and geochemistry, including vertebrate, plant, and pollen fossils as well as oxygen,carbon, and hydrogen isotopes. he Tibetan Plateau is the youngest and highest plateau on Earth, and its paleoaltimetry reconstructions are crucial to interpret its geodynamic evolution and to understand the climatic changes in Asia. Uplit histories of the Tibetan Plateau based on diferent proxies difer considerably, and two viewpoints are pointedly opposing on the paleoaltimetry estimations of the Tibetan Plateau. One viewpoint is that the Tibetan Plateau did not strongly uplit to reach its modern elevation until the Late Miocene, but another one, mainly based on stable isotopes, argues that the Tibetan Plateau formed early during the Indo-Asian collision and reached its modern elevation in the Paleogene or by the Middle Miocene. With either a geochemical or paleontological approach, the present is used as the key to the past.However, there are great diiculties because modern processes of isotopic fractionation and species for creature distribution are not easily precisely determined. In addition, the climatic and environmental backgrounds of past geological times have massive diferences from the present, and associated adjustments are inluenced by many human factors. In the future work, the applications of multidisciplinary comprehensive methods and cross-checks of their results will be productive, and we look forward to achieving more reliable estimates for paleoelevations of the Tibetan Plateau.

关键词： Tibetan Plateau Cenozoic paleoelevation paleontology stable isotope

How does the elevation changing response to crustal thickening process in the central Tibetan Plateau since 120 Ma?

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China Geology 2021年第1期4卷 32-43页

作者： Zhong-bao Zhao Chao Li Xu-xuan Ma Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

When and how the Tibetan Plateau formed and maintained its thick crust and high elevation on Earth is continuing debated.Specifically,the coupling relationship between crustal thickening and corresponding paleoelevation changing has not been well studied.The dominant factors in crustal thickness changing are crustal shortening,magmatic input and surface erosion rates.Crustal thickness change and corresponding paleoelevation variation with time were further linked by an isostatic equation in this study.Since 120 Ma crustal shortening,magmatic input and surface erosion rates data from the central Tibetan Plateau are took as input parameters.By using a one-dimensional isostasy model,the authors captured the first-order relationship between crustal thickening and historical elevation responses over the central Tibetan Plateau,including the Qiangtang and Lhasa terranes.Based on the modeling results,the authors primarily concluded that the Qiangtang terrane crust gradually thickened to ca.63 km at ca.40 Ma,mainly due to tectonic shortening and minor magmatic input combined with a slow erosion rate.However,the Lhasa terrane crust thickened by a combination of tectonic shortening,extensive magmatic input and probably Indian plate underthrusting,which thickened the Lhasa crust over 75 km since 25 Ma.Moreover,a longstanding elevation>4000 m was strongly coupled with a thickened crust since about 35 Ma in the central Tibetan Plateau.

关键词： Crustal thickness paleoelevation Isostatic modeling Qiangtang terrane Lhasa terrane Tibetan Plateau China

Empirical relationship between leaf wax n-alkaneδD and altitude in the Wuyi,Shennongjia and Tianshan Mountains,China:Implications for paleoaltimetry

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Empirical relationship between leaf wax n-alkaneδD and alti...