天目山泥炭有机碳同位素特征及其古环境意义

Organic Carbon Isotopic Characteristics and Their Paleoenvironmental Implications:A Case Study of the Tianmushan Peat Bog

通过对浙江天目山泥炭剖面的高密度采样和有机碳同位素分析,重建了该地区4kaBP以来的古植被特征和古环境演化历史。天目山3200aBP之前,气候温和适度,晚期变冷变干,为中全新世末气候波动的过渡时期。3200～700aBP,有机碳δ13Corg值在波动中降低,气候出现多次急剧冷暖变化,指示了几次温暖与寒冷事件。700aBP以来,有机碳同位素迅速正偏,表明又一暖期的出现,到了后期气温又有所降低,植被转化为草原草甸景观。天目山地区近4ka以来的气候变化与国内外不同区域的研究资料相一致,但又有区域的差异性。

Organic carbon isotope and lipid biomarker were used to determine paleovegetation characteristics and paleoenvironment changes of the Tianmushan Area, Zhejiang Province since the Middle Holocene. A combined analysis of organic carbon isotope signature and lipid biomarker depicted three remarkable paleoenvironment stages. Before 3200 a BP, the climate was relatively stable in spite of a cold - dry trend in the late stage, implying a transitional period. From 3200 to 700 a BP, it was a changeable period characterized by a couple of warm and cold events. The climate after 700 a BP was rela- tively warm first and became a bit cooler afterwards, possibly suggesting that the vegetation was dominated by grass plants. Significantly, the results obtained by the authors are well in line with the results of related comparative researches of different areas, thereby demonstrating the global traits and local characteristics of the paleoclimatic process and providing a useful basis for global change comparison.