HR: 0800h
AN: PP11B-0517    [Abstracts]
TI: Assessing Palaeomonsoon Variability During the Late Quaternary Using Evidence From the Lake Sediment Archives of Yunnan Province, China
AU: * Dew, C G
EM: cd238@exeter.ac.uk
AF: University of Exeter, School of Geography, Streatham Campus, Amory Building, Rennes Drive, Exeter, EX4 4RJ, United Kingdom
AU: Jones, R T
EM: r.t.jones@exeter.ac.uk
AF: University of Exeter, School of Geography, Cornwall Campus, Treliever Road, Penryn, TR10 9EZ, United Kingdom
AU: Zhang, E
EM: elzhang@niglas.ac.cn
AF: Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
AU: Leng, M J
EM: mjl@nigl.nerc.ac.uk
AF: NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG, United Kingdom
AU: Langdon, P G
EM: P.G.Langdon@soton.ac.uk
AF: University of Southampton, School of Geography, Highfield, Southampton, SO17 1BJ, United Kingdom
AU: Caseldine, C J
EM: C.J.Caseldine@exeter.ac.uk
AF: University of Exeter, School of Geography, Cornwall Campus, Treliever Road, Penryn, TR10 9EZ, United Kingdom
AB: The acquisition of well distributed, high resolution records of Asian palaeomonsoon variability remains an outstanding issue (Wang et al 2005), particularly for high altitude sites in Southwestern China where our understanding of the regional climate as a whole is limited. This sub-region is climatically sensitive because it is in the convergence zone of the Indian, East Asian and Western North Pacific monsoon subsystems of the Asian Monsoon (Yihui and Chan 2005), delineated by the line of 105°E longitude, which runs along the eastern flank of the Tibetan Plateau (Wang et al 2003). Characterising the nature, timing and magnitude of southwestern monsoon variability facilitates further understanding of the possible socio-economic and environmental consequences that may result from climate change. This NERC-funded PhD research project (2005-8) focuses on a high altitude lake sediment core extracted from Lake Shudu, Yunnan Province, China, on the southeastern edge of the Tibetan Plateau. The project aims are to produce a detailed record of southwestern monsoon variability spanning the Late Quaternary, and to compare the results with other regional records in order to better understand monsoonal patterns across western China. The sediments are being analysed using a range of proxy measures including pollen, stable isotopes (δ¹³C) and lithological indicators (mineral magnetics, C/N, particle size and TOC). Bulk ¹⁴C AMS dates obtained for the seven metre core suggest that it represents the last ca. 22ka cal yr BP. Six clear phases of change have been identified in the lithological and carbon isotope records. Several notable shifts in the balance of arboreal and grass pollen also appear in the pollen record. It is suggested that the core records a history of dynamic changes, initially driven by changes in climatic conditions. However, in more recent times, changes in catchment vegetation and lithology point to increased catchment disturbance associated with the onset of anthropogenic activity. The results suggest that the core may represent one of the first high-resolution palaeoclimatic records spanning the Late Glacial Interstadial Transition (LGIT) and the Early Holocene for Southwestern China.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4942 Limnology (0458, 1845, 4239)
DE: 4952 Palynology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting