末次冰盛期以来东北地区霍拉盆地湖泊沉积物记录的C3／C4植被演化  

C3/C4 VEGETATION EVOLUTION RECORDED BY LAKE SEDIMENTS IN THE HUOLA BASIN, NORTHEAST CHINA SINCE THE LAST GLACIAL MAXIMUM

作　　者：马雪云 魏志福 王永莉[4] 汪亘[1,2] 巩俊成 张婷[1,2,3] 何薇 玉晓丽 Ma Xueyun;Wei Zhifu;Wang Yongli;Wang Gen;Gong Juncheng;Zhang Tlng;He Wei;Yu Xiaoli(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu;Key Laboratory of Petroleum Resources,Gansu Province/Key Laboratory of Petroleum Resources Research,Chinese Academy of Sciences,Lanzhou 730000,Gansu;University of Chinese Academy of Sciences,Beijing 100049;Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室,甘肃兰州730000 [3]中国科学院大学,北京100049 [4]中国科学院地质与地球物理研究所,中国科学院新生代地质与环境重点实验室,北京100029

出　　处：《第四纪研究》2018年第5期1193-1202,共10页Quaternary Sciences

基　　金：国家重点研究发展计划项目（批准号：2017YFA0604803）、国家自然科学基金项目（批准号：41572350和41503049）、西部之光一般项目以及甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室开放课题（批准号：1309RTSA041）共同资助

摘　　要：利用气相色谱-质谱（GC-MS）联用技术对我国大兴安岭北部霍拉盆地湖泊沉积物进行了有机分子地球化学分析，检测出了丰富的正构烷烃。本研究主要讨论了正构烷烃的分布特征及其长链正构烷烃的单体碳同位素组成，结合AMS 14C年代数据，重建中国东北大兴安岭地区末次冰盛期以来的古植被及古气候变化。正构烷烃分布特征表明，末次冰盛期以来，霍拉盆地湖沼沉积物长链正构烷烃呈现明显的奇碳优势，主峰碳主要为nC31，指示有机质主要来源于陆生高等植物，且草本植物输入占优势，木本植物输入丰富。陆生高等植物来源的长链正构烷烃单体稳定碳同位素的记录显示，末次冰盛期晚期以来古莲剖面沉积物长链正构烷烃（nC27、nC29和nC31）稳定碳同位素整体偏负；此外，利用二元模式估算了C3/C4植物相对生物量，结果表明，自末次冰盛期以来我国东北大兴安岭地区C3植物占绝对优势，然而在全新世大暖期C4植物生物量呈现明显扩张趋势，这表明气候变暖对C4植物量的增加有重要影响。The Huola River basin（52°57＇N^53°03＇N, 121°52＇E^122°04＇E）, located in Heilongjiang Province, belongs to the northern part of the Daxing＇anling permafrost region. The Gulian profile（53°00＇38.88＂N, 121°57＇48.24＂E） is developed in the Huola valley basin around the mountain at an elevation of 535 m. The thickness of this section is 300 cm with a gravel bottom. The lower part（300~70 cm） is typical lake sediments and the upper part （70~0 cm） is peat. A total of 150 samples were collected with an interval of 2 cm. Five charcoal samples were sent to the Australian Nuclear Science and Technology Center Ansto Accelerator Laboratory for AMS 14C dating. The characteristics of biomarkers extracted from the limnological sediments taken from Gulian Section of Huola basin in Northern Daxing＇anling were systematically analyzed by gas chromatography-mass spectrometry （GC/MS） for the first time. Besides, Compound-specific carbon isotopic composition was tested by mass spectrometer （Trace GC, MAT 253）. Combined with 14C dating, the paleovegetation and paleoclimatic changes since the Last Glacial Maximum period in the Daxing＇anling region of Northeast China were reconstructed. The distribution of （nC27, nC29 and nC29） n-alkanes indicated that the long-chain n-alkanes of the lake sediments in the Gulian section of Huola Basin had obvious odd carbon advantages and the main peak carbon is mainly nC31 since the Late Glacial period, indicating that the organic matters were mainly derived from terrestrial plants. The n-alkanes index（nC27/nC31） had a distribution range of 0.43~1.01, suggesting that the input of herbs was dominated, and the input of woody plants was abundant. The stable carbon isotope records（-35.7 ‰ 〈 δ13nC27 〈 -32.0 ‰, -36.7 ‰ 〈 δ13nC29 〈 -32.4 ‰） of long-chain normal n-alkanes derived from terrestrial plants showed that the stable carbon isotope of the long-chain n-alkanes （nC27, nC29 and nC31） in the Gulian section was negative since th

关 键 词：湖泊沉积物 正构烷烃 长链烷烃单体碳同位 古植被 大兴安岭地区 

分 类 号：P941.78[天文地球—自然地理学] P593