Elucidation of changes in long-term environments and biological systems in the northeast Asia by the use of lake sediments in the Lake Baikal basin

利用贝加尔湖盆地的湖泊沉积物阐明东北亚长期环境和生物系统的变化

• 批准号: 16310012
• 负责人: INOUE Genki
• 金额: $ 9.73万
• 依托单位: Otsuma Women's University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310012/
• 关键词: Lake Baikal basin; Lone-term environmental change; Sediment core; Biomarker; Fossol pollen; 環境変動; 湖底堆積物コア; 光合成色素続成生成物; バイカル集水域

We studied changes in long-term paleoenvironment for 1.03 million years and biological systems in the northeast Asia by the use of biomarkers including plant pigments, and fossil pollens in sediment cores from Lake Hovsgol in the Lake Baikal basin. Direct pyrolysis and methylation of sediment samples combined with gas chromatography-mass spectrometry (PyMeGCMS) were, in addition, carried out to develop rapid analysis of biomarkers in the sediment cores.Gravity cores (X106, HV05ST2, HV05ST3) have detailed information on changes in paleoenvironment and biological systems during the last glacial period to the present. AMS dating (conventional age) of the cores showed sediment ages were less than 24,000 years. Biological production in the glacial period based on total organic carbon (TOC) contents was very low, increased to Bolling-Allerod (ca. 12,000 yBP), decreased to Younger Dryas event (ca. 11,000 yBP) and then increased again to the post glacial period. Scarce herbaceous plant vegetat … More ion such as Altemisia spp. on the land and small amount of plankton were distributed under perennial ice cover in the glacial period. Woody plant vegetation increased in the warm post glacial period, along with increase of lake plankton.Sedimentation ages of HDP04 sediment core (80.0 m) were determined 1.03 million years by paleomagnetism (Brunhes-Matuyama, Jaramillo Chron). Pattern of TOC contents of the core was well not correlated with that of marine isotope stages, reflects largely local climatic changes in the drainage basin rather than global climatic changes. Biological production in Lake Hovsgol was relatively low for the last 1.03 million years except for Holocene, and was somewhat lower than that of Lake Baikal. Contribution of allocthonous organic matter in Lake Hovsgol was much higher than that of Lake Baikal, reflecting probably small drainage basin of Lake Hovsgol. The presence of bacteriochlorophyls specific to brown-Chlorobium in the depths between 19-21 m of the core suggests strongly that lake bottom was anoxic due to the stagnant of the lake water.A series of fatty acids and phenolcarboxylic acid were detected in HV05ST2 sediment core by PyMeGCMS. The pattern of these compounds were similar to that of those compounds found in ethyl acetate extracts of the core, revealed that PyMeGCMS was useful for the rapid determination of biomarkers in the sediment core. Less

我们利用贝加尔湖霍夫斯戈尔湖沉积岩芯中的植物色素和化石花粉等生物标志物，研究了103万年来东北亚地区长期的古环境和生物系统的变化。此外，沉积物样品的直接热解和甲基化与气相色谱-质谱仪(PyMeGCMS)相结合，建立了沉积物岩芯中生物标志物的快速分析方法。重力岩芯(X106，HV05ST2，HV05ST3)包含了从最后一次冰期到现在的古环境和生物系统的详细信息。岩心的AMS测年(常规年龄)表明，沉积年龄不到24,000年。以总有机碳(TOC)含量为基础的冰期生物生产量非常低，增加到Bolling-Allerod(约12000yBP)，减少到年轻仙女木事件(约11000yBP)，然后又增加到冰后期。稀有草本植物…较多的离子，如艾蒿等。在冰期，陆地和少量浮游生物分布在常年冰盖下。木本植物植被在温暖的冰后期随着湖泊浮游生物的增加而增加。利用古地磁学方法(Brunes-Matuyama，Jaramillo Chron)确定了HDP04沉积岩芯(80.0m)的沉积年龄为103万年。岩心TOC含量模式与海相同位素期相关性不强，主要反映了流域局部气候变化，而不是全球气候变化。除全新世外，近103万年来，霍夫斯戈尔湖的生物生产量相对较低，略低于贝加尔湖。霍夫斯戈尔湖的局地有机质贡献远高于贝加尔湖，可能反映了霍夫斯戈尔湖小流域。在岩心19~21m深度内发现的棕绿藻类特有的细菌叶绿素强烈表明，由于湖水的滞留，湖底处于缺氧状态。利用PyMeGCMS在HV05ST2沉积物岩心中检测到一系列脂肪酸和酚羧酸。这些化合物的图谱与岩心乙酸乙酯萃取物中发现的化合物相似，表明PyMeGCMS可用于沉积物岩心生物标志物的快速测定。较少