HR: 0830h
AN: B31D-0325    [PDF]
TI: Distribution and Sources of Lignin Monomers in Late Quaternary Sediments From Southwestern Coastal Plain of Taiwan
AU: * Ku, H
EM: philicity@ms1.url.com.tw
AF: National Taiwan University, Department of Geosciences, No.1, Sec. 4, Roosevelt Road, Taipei, 106 Taiwan
AU: Chen, Y
EM: ygchen@ntu.edu.tw
AF: National Taiwan University, Department of Geosciences, No.1, Sec. 4, Roosevelt Road, Taipei, 106 Taiwan
AU: Filley, T R
EM: filley@purdue.edu
AF: Purdue University, Department of Earth and Atmospheric Sciences, 1397 Civil Engineering Building, West Lafayette, IN 47906 United States
AU: Liu, T
AF: National Taiwan University, Department of Geosciences, No.1, Sec. 4, Roosevelt Road, Taipei, 106 Taiwan
AB: In an effort to understand paleoenvironmental changes of the southwestern coastal plain of Taiwan over the past 50K years, we employed molecular and stable isotope techniques to sediment cores to study shifts in organic carbon input and plant communities. Preliminary results show that, during the Holocene (the last 10K yrs), large shifts in bulk stable carbon isotope values are observed suggesting either shifts C3/C4 communities or changes in algal productivity. Moreover, lithologic variations in lignin monomer proxies indicate wide a variation in the degree of microbial oxidation based on elevated vanillyl Acid/Aldehyde ratios. The carbon-normalized yield of 8 vanillyl, syringyl, and cinnamyl phenols shows wide variation during periods in the late Pleistocene and Holocene. The Holocene-Pleistocene boundary exhibits a sharp change of TOC, vanillyl Acid/Aldehyde ratio, and lignin yield. However, variations still exist between cores due to different regional sedimentary environments. Studies are ongoing to relate nitrogen and sulfur cycling to organic carbon input.
DE: 0400 Biogeosciences
DE: 1040 Isotopic composition/chemistry
DE: 1055 Organic geochemistry
SC: Biogeosciences [B]
MN: 2003 Fall Meeting