Diachronous uplift of the Tibetan plateau starting 40?Myr ago

Abstract

Nature © Macmillan Publishers Ltd 19988 with occasional peaks up to 17. Furthermore, the peak in charcoal abundance inferred by Verardo and Ruddiman 17 at the Last Glacial Maximum corresponds to samples with a very small range of C/N ratios between 8 and 12, suggesting that these samples are predominantly composed of marine-derived carbon. Isolated peaks in C/N ratio up to 18 in some samples may correspond to events similar to those identified in ODP-668B.Second, the flux rates of elemental carbon calculated by Verardo and Ruddiman 17 range as high as 50,000 g cm −1 kyr −1 , which is two orders of magnitude higher than calculated for a range of recent, Quaternary and Tertiary marine sediments by other researchers. Smith et al. 16 calculated an average pre-industrial flux rate for Pacific and Atlantic sediments of 100 g cm −1 kyr −1 , whereas Herring 11 calculated Quaternary fluxes of 3-600 g cm −1 kyr −1 and Tertiary fluxes of 0.3-10 g cm −1 kyr −1 for Pacific Ocean sediments remote from coastal regions. These values agree well with the OREC fluxes calculated for ODP-668B (1-400 g cm −1 kyr −1 ), despite the fact that the data were generated by different techniques.A sample of Antarctic marine sediment previously shown by Bird and Gröcke 28 to contain Ͻ1% elemental carbon was analysed in triplicate using the Verardo and Ruddiman 17 technique. The results indicate that only 49 Ϯ 5% of the carbon in this sample was removed by in situ nitric acid oxidation, implying an elemental carbon content of around 50%. It is possible that, whereas some organic carbon is oxidized directly to CO 2 , a considerable quantity of more refractory organic carbon is only partly oxidized and solubilized by the treatment but not removed, leading to an overestimate of 'charcoal' abundance using the Verardo and Ruddiman technique.The OREC results from our study suggest that during the transition from interglacial to glacial mode the regional climate may have been destabilized and highly variable, leading to the buildup of fuel loads during wet periods followed by intense biomass burning in subsequent dry periods. In addition, biomass burning may be one mechanism by which high terrestrial organic carbon stocks built up during interglacials are shed at the onset of the subsequent glaciation.The most recent peak in OREC abundance is unique in the past million years, in that it has occurred during an interglacial period. Anthropogenic biomass burning is considered the likely cause of this peak. Given that the current conditions of interglacial aridity in the region are also considered by some to be unusual [5][6][7]22 , further consideration should be given to the possibility that a range of human activities in sub-Saharan Africa may have resulted in regional modifications to 'natural' vegetation patterns and climate. Ⅺ

The uplift of Qinghai-Xizang (Tibet) Plateau and the vicariance speciation of glyptosternoid fishes (Siluriformes: Sisoridae)

“…This result indicated that the east Himalayas uplifted earlier than the west. This hypothesis is similar to that of Chung et al [11] 2.3.1 The explanation of dispersal ( fig. 4(a)).…”

Evolutionary events in Lilium (including Nomocharis, Liliaceae) are temporally correlated with orogenies of the Q–T plateau and the Hengduan Mountains

“…The rich topography of the plateau and its broad-reaching climatic influence have probably favored the evolution of the diverse flora of eastern Asia; namely within the its mountain ranges but also within Japan and central China (Richardson et al, 2001a,b;Willis and Whittaker, 2002;Wharton et al, 2005;Liu et al, 2006). Uplift of the plateau began approximately 40 million years ago (Mya) in the Eocene (Chung et al, 1998). Recent evidence indicates that the southern margin reached its present elevation approximately 15-22 Mya (Guo et al, 2002;Spicer et al, 2003) and that the whole plateau may have attained its present altitude by 7-8 Mya (Harrison et al, 1992).…”

Influence of the Tibetan Plateau uplift on the Asian monsoon-arid environment evolution

“…New geological evidences [14,67,71,72] were more likely to support the asynchronous uplift in different regions of the TP. Namely, the rate and amplitude of the uplift might vary in different sub-regions of the plateau.…”

“…According to the difference in the eruption time of the high-K lava in the west and east regions of the Qiangtang Plateau, Chung et al [71] suggested that different locations of the TP had various uplift history. Based on the oblique subduction of continental lithosphere, Tapponnier et al [67] proposed a multi-stage uplift model where the TP uplifted subregionally, gradually advancing from south to north.…”