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

• Published in: Chinese science bulletin 2012-12, Vol.57 (36), p.4753-4764
• Main Authors: Wang, Yong, Zhu, LiPing, Wang, JunBo, Ju, JianTing, Lin, Xiao
• Format: Article
• Language: English
• Subjects: Algae; alkanes; bacteria; carbon; Chemistry/Food Science; Earth Sciences; Engineering; Freshwater; Humanities and Social Sciences; lakes; Life Sciences; multidisciplinary; nitrogen content; organic matter; Physics; rivers; Science; Science (multidisciplinary); sediments; submerged aquatic plants; topography; water quality; 有机物质; 正构烷烃; 沉积过程; 空间分布格局; 空间变异性; 纳木错; 表层沉积物; 青藏高原中部
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-012-5500-9

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.