Later Pleistocene/Holocene climate conditions of Qinghai–Xizhang Plateau (Tibet) based on carbon and oxygen stable isotopes of Zabuye Lake sediments

Wang, R.L.; Scarpitta, S.C.; Zhang, S.C.; Zheng, Mianping

doi:10.1016/s0012-821x(02)00829-4

Cited by 128 publications

(79 citation statements)

References 32 publications

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“…On the Tibetan Plateau, cold and dry conditions during marine isotope stage 2 were followed by a warm and humid period with high lake levels in the early-mid Holocene (e.g. Wang et al, 2002;Mügler et al, 2010). A subsequent phase of increased aridity, which started 5-6 ka ago, is documented by falling lake levels (e.g.…”

Section: Uncertainties Of the 10 Be Denudation Ratesmentioning

confidence: 99%

Landscape evolution of a bedrock peneplain on the southern Tibetan Plateau revealed by in situ-produced cosmogenic 10Be and 21Ne

et al. 2012

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: Landscape evolution of a bedrock peneplain on the southern Tibetan Plateau revealed by in situ-produced cosmogenic 10Be and 21Ne.-Geomorphology, [153][154][192][193][194][195][196][197][198][199][200][201][202][203][204] AbstractLow-relief bedrock surfaces that occur at high altitude are a common feature of Cenozoic mountain belts and have often been used to infer a significant amount of rock uplift after their generation at low elevation. The timescale over which such surfaces can be preserved at high elevation and the rate at which they are modified by weathering and erosion are poorly known. Here we use cosmogenic 10 Be and 21 Ne to quantify the landscape evolution of a bedrock peneplain in southern Tibet that occurs at an altitude of ~5300 m. The peneplain is developed in Cretaceous granitoids and Jurassic metasediments of the northern Lhasa block (90°E, 31°N) and originally had a minimum extent of ~150 km east-west and ~75 km northsouth. It has been dissected by small rivers that generated a few hundred meters of relief and formed additional bedrock surfaces of limited extent at lower elevation. Local denudation rates for the peneplain and the lower bedrock surfaces -based on 10 Be concentrations in grus samples and amalgamated quartz clasts -cluster between 5 and 11 m Ma -1 (mean = 8.1 m Ma -1 ) and are thought to be representative for the long-term rate of downwearing of these surfaces. Samples from bedrock outcrops and bedrock blocks yield more variable rates (3-20 m Ma -1 ), which partly overestimate the long-term lowering rate, presumably due to block tilting and bedrock inhomogeneity. Spatially averaged 10 Be denudation rates for small river catchments range from 9 to 16 m Ma -1 (mean = 11.8 m Ma -1 ) and are only slightly higher than the local denudation rates. Hence, the incision and widening of valleys proceeds at low rates, which demonstrates that the landscape of the peneplain region is remarkably stable. The combined 21 Ne and 10 Be data in a subset of the samples suggest that the bedrock surfaces have experienced a simple exposure history without periods of burial. Thus, our data do not provide any evidence for extended periods of shielding by ice during past glaciations, which is consistent with the absence of erratic boulders and moraines in the peneplain region.

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Section: Uncertainties Of the 10 Be Denudation Ratesmentioning

confidence: 99%

Landscape evolution of a bedrock peneplain on the southern Tibetan Plateau revealed by in situ-produced cosmogenic 10Be and 21Ne

et al. 2012

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“…Accordingly, lake sediments are being widely and thoroughly studied in this area, because there are more than 1000 lakes with areas greater than 1 km 2 present on the plateau [7]. Although these lakes provide many natural environmental archives for past environmental changes [8][9][10][11][12][13][14], the explanations of the proxies are still based on lake studies of the lowland or other areas. However, for lakes with complicated sedimentary environments, especially large lakes, it is essential to under-stand the spatial distribution and enrichment conditions of sediments when reconstructing the paleoclimate and paleoenvironment [15,16].…”

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confidence: 99%

The spatial distribution and sedimentary processes of organic matter in surface sediments of Nam Co, Central Tibetan Plateau

et al. 2012

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In this study, 67 surface sediment samples collected from Nam Co in central Tibet were analyzed for total carbon, total organic carbon and total nitrogen, and 51 of these samples were also analyzed for n-alkanes. The origin and spatial distribution of organic matter were then investigated using these proxies, and the control factors responsible for the spatial distribution patterns and paleolimnological significance were discussed. The results indicated that the origin of organic matter in surface sediment of Nam Co is consistent with the sources of n-alkanes, which were primarily submerged plants, followed by terrestrial plants, and then aquatic algae and bacteria. The organic matter in surface sediments of the lake showed typical spatial variability. Because of the great influence of underwater topography, river inputs and water quality, the spatial distribution of organic matter is enriched from the source to the deposit center. This spatial variability of organic matter in the lake indicates that the sediments in different areas have different sensitivities to environmental changes, which is important to reconstruction of paleoenvironments and paleoclimate using lake sediment cores.Tibetan Plateau, Nam Co, surface sediments, spatial distribution, sedimentary processes Citation:Wang Y, Zhu L P, Wang J B, et al. The spatial distribution and sedimentary processes of organic matter in surface sediments

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“…High-resolution lake sediment records have been obtained from Yidun Lake [6] in southern Tibet and Ren Co [7] in the southeastern Plateau, Yanmdrok Lake [13] in the southern Plateau, and Peiku Co [8] and Zabuye Lake [12] in the southwestern Plateau. Moreover, the recent environmental records of Naleng Lake [31] in the eastern Plateau and Ximen Co [32] are dominated by glacial meltwater supplies, and could be compared with our results, even though both lakes experience the influence of the southeast monsoon.…”

Section: Comparison With Other Lakes Records In Southern Tibetmentioning

confidence: 99%

“…To date, lake sediment records have obtained only limited coverage in the southern Tibetan Plateau region [5][6][7][8][9][10]. In addition, there is a lack of highresolution records that encompass the deglacial stage [11][12][13]. Thus, more long time scale palaeoclimatic studies are needed.…”

mentioning

confidence: 99%

A high-resolution environmental change record since 19 cal ka BP in Pumoyum Co, southern Tibet

Zhu

Nishimura

et al. 2011

Chin. Sci. Bull.

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A 380-cm-long sediment core was acquired from the deep water area of Pumoyum Co, southern Tibet. Twenty-five plant residue samples were selected, and organic carbon stable isotopes were obtained using the AMS 14 C chronological method. The 14 C age and carbon reservoir effect were calibrated with surface sedimentation rate measurements using 210 Pb dating. Results showed that the core sediment deposited over 19 cal ka BP. Based on a multi-proxy analysis of TOC and IC contents, grain size and pollen assemblage data, the palaeoclimatic evolution of Pumoyum Co was reconstructed since the last glacial. Pumoyum Co was a shallow lake prior to 16.2 cal ka BP; although the glacier around the lake began to melt due to increasing temperatures, climate was still cold and dry. In the interval of 16.2-11.8 cal ka BP, the sedimentary environment fluctuated drastically and frequently. Two cold-events occurred at 14.2 and 11.8 cal ka BP, and these may correspond to the Older Dryas and the Younger Dryas events, respectively. After 11.8 cal ka BP, Pumoyun Co developed into the deep lake as it is now. The lake water temperature was relatively lower at that time because of influx of cold water from glacial meltwater entering the lake. As a result, the multi-proxy indicators showed no sign of warm conditions. Comparisons between the sedimentary record of Pumoyum Co with that of other lakes of the same age in southern Tibet indicate a warmer climate following the last deglaciation influenced the southeastern Tibetan Plateau. These results imply that the southwest Asian monsoon gradually became stronger since the deglaciation during its expansion to the inner plateau. The glacial-supplied water of the lake responded sensitively to cold-events. The entire southern Tibet region was dominantly influenced climatically by the southwest Asian monsoon during the Holocene.Tibet, Pumoyum Co, lake sedimentation, environmental change, high resolution, glacial meltwater Citation:Lü X M, Zhu L P, Nishimura M, et al. A high-resolution environmental change record since 19 cal ka BP in Pumoyum Co, southern Tibet.

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Later Pleistocene/Holocene climate conditions of Qinghai–Xizhang Plateau (Tibet) based on carbon and oxygen stable isotopes of Zabuye Lake sediments

Cited by 128 publications

References 32 publications

Landscape evolution of a bedrock peneplain on the southern Tibetan Plateau revealed by in situ-produced cosmogenic 10Be and 21Ne

Landscape evolution of a bedrock peneplain on the southern Tibetan Plateau revealed by in situ-produced cosmogenic 10Be and 21Ne

The spatial distribution and sedimentary processes of organic matter in surface sediments of Nam Co, Central Tibetan Plateau

A high-resolution environmental change record since 19 cal ka BP in Pumoyum Co, southern Tibet

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