CAJ | 학술논문

以松嫩平原西部向海1420 cm 湖泊沉积物剖面为研究对象,根据 AMS 14 C 年代信息建立末次冰消期以来的年代序列；结合沉积物类型、有机质丰度,重点对样品中正构烷烃及长链正构烷烃碳同位素等分子有机地球化学特征进行研究；通过综合对比各气候指标,重建该地区末次冰消期以来的古植被、古气候变化。结果表明：向海湖泊沉积物中正构烷烃的分布特征表明其主要来源于低等菌藻类生物和高等植物；正构烷烃的高碳数部分呈现明显的奇碳优势,高碳数部分主峰碳主要为 nC31,指示有机质主要来源于陆生高等植物,且草本高等植物输入丰富；长链正构烷烃(nC27、nC29、nC31)稳定碳同位素整体呈偏正的趋势,并利用二元模式估算出湖区主要高等植被类型以 C3植物占绝对优势,末次冰消期到全新世大暖期 C4植物相对生物量增加；末次冰消期以来,研究区气候环境变化较不稳定,可分为5个阶段,分别为气候冷干的末次冰消期,气候冷湿的早全新世,气候暖干的中全新世大暖期前期,气候温暖湿润的中全新世大暖期后期以及气候温凉变干的晚全新世。
이송눈평원서부향해1420 cm 호박침적물부면위연구대상,근거 AMS 14 C 년대신식건립말차빙소기이래적년대서렬；결합침적물류형、유궤질봉도,중점대양품중정구완경급장련정구완경탄동위소등분자유궤지구화학특정진행연구；통과종합대비각기후지표,중건해지구말차빙소기이래적고식피、고기후변화。결과표명：향해호박침적물중정구완경적분포특정표명기주요래원우저등균조류생물화고등식물；정구완경적고탄수부분정현명현적기탄우세,고탄수부분주봉탄주요위 nC31,지시유궤질주요래원우륙생고등식물,차초본고등식물수입봉부；장련정구완경(nC27、nC29、nC31)은정탄동위소정체정편정적추세,병이용이원모식고산출호구주요고등식피류형이 C3식물점절대우세,말차빙소기도전신세대난기 C4식물상대생물량증가；말차빙소기이래,연구구기후배경변화교불은정,가분위5개계단,분별위기후랭간적말차빙소기,기후랭습적조전신세,기후난간적중전신세대난기전기,기후온난습윤적중전신세대난기후기이급기후온량변간적만전신세。
The section of 1 420 cm lake sediment from Xianghai in the western of Songnen Plain was investigated.According to the AMS 1 4 C dating,the chronology of lake sediment since Last Deglaciation was established;combined with the types of sediment and the abundance of organic matter,molecular organic geochemical characteristics including carbon isotopic compositions of n-alkanes and long-chain n-alkanes in the samples were analyzed;compared with the climatic indicators of sediment core, the changes of paleovegetation and paleoclimate since Last Deglaciation were evaluated.The results show that the organic matters in lake sediment are mainly derived from algae and higher plant according to the distribution of n-alkanes from lake sediment in Xianghai;the n-alkanes exhibit strong odd-carbon number predominance,and the main peak of high carbon number of n-alkanes is nC3 1 ,so that the organic matters are mainly derived from terrestrial higher plants,especially herbaceous higher plants;the carbon isotopic compositions of long-chain n-alkanes (nC2 7 ,nC2 9 and nC3 1 )are positive in whole,and the main higher vegetation type in the lake is C3 plant dominantly by the means of binary pattern,and the relative biomass of C4 plant increases from Last Deglaciation to the megathermal of Holocene;the change of climate fluctuates since Last Deglaciation,and the climatic and environmental changes in the study area can be divided into five stages including cold and dry in Last Deglaciation,cold and wet in Early Holocene,warm and dry in the early megathermal of Holocene,warm and wet in the late megathermal of Holocene,and warm-cool and drying in Late Holocene.