摘要
湖泊沉积物中有机碳的总量（TOC）取决于湖泊的初始生产力及有机质沉积后的保存能力,而有机碳的稳定同位素（δ^(13)C）值则反映了不同来源有机质的组成以及流域古植被状况。本文通过对内蒙呼伦湖东露天煤矿剖面TOC及δ^(13)C值的垂直分布的研究,结合剖面的沉积特征及孢粉、硅藻分析结果,讨论了呼伦湖地区末次冰期以来古气候古环境演化过程。结果表明有机碳的总量及其稳定碳同位素可作为分析古气候环境的一种有效的代用指标。
Total organic carbon (TOC) in lake sediment s depends on the input of organic matter, the primary production of lake itself and its preservation potency while the stable isotope value (13C) of organic carbon reflects the combination of different sources of organic matter and the paleovegetation in the drainage area-According to the vertical distribution of TOC and 13C, combined with the sedunentary characteristics, sporo-pollen and diatom from Donglutian coalfild of Hulun Lake, Inner Mongolia, the paleoenvironmental evolution of this region since last Glaciation has been reconstructed as follows:the lake pioneering period of LGM or a bit later, cold and dry; the highest lake level period of the second half of Post Clacial (13000 -10900 a B. P. ), temperate and wet; Younger Dryas Period (10900- 10600a B. P. ), cold and dry; the higher lake level period at the beginning of Holocene ( 10600-10000a B. P. ), temperate and wet; the intermediate-low lake level in the Early Holocene (10000-7200a B. P. ) , temperate and dry; the higher lake level of Middle Holocene (7200 -5000a B. P. ), warm and wet; the strong shrinkage period in the late Middle Holocene (5000- 3000a B. P. ), temperate and dry.
出处
《湖泊科学》
EI
CAS
CSCD
1994年第4期308-316,共9页
Journal of Lake Sciences
基金
国家自然科学基金项目(49172119)
关键词
湖泊
沉积物
有机碳
稳定同位素
古环境演化
Lake sediments, total organic carbon, stable isotope of oranic carbon,paleoenvironmental evolution, Hulun Lake
