| 张慧娟.银川盆地35ka以来古植被演化的类脂分子记录[J].地质与勘探,2019,55(1):152-159 |
| 银川盆地35ka以来古植被演化的类脂分子记录 |
| Regional paleovegetation evolution recorded in molecular lipid of lacustrine sediments from Yinchuan basin since 35ka |
| 投稿时间：2018-03-12 修订日期：2018-10-20 |
| DOI：10.12134/j.dzykt.2019.01.015 |
| 中文关键词: 正构烷烃 有机碳同位素 有机质来源 古植被演化 银川盆地 |
| 英文关键词: n-alkane, organic carbon isotope organic source, paleovegetation, Yinchuan Basin |
| 基金项目:北京市自然科学基金委项目（编号：8162038）、中央高校经费基本科研业务费优秀教师基金项目（编号：2652017216）和国际合作与交流项目（编号：2652017285）联合资助 |
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| 中文摘要: |
| 为了更好地了解干旱-半干旱区的植被类型及其演化规律，利用气相色谱仪对银川盆地冰沟剖面河湖相沉积物中的正构烷烃进行了检测，结果显示其正构烷烃碳数分布范围为C15~C34，奇碳优势明显，以C29或C31为主峰的单峰型为主，但少量样品也出现双峰型分布模式。通过对冰沟剖面正构烷烃分布特征、碳优势指数CPI和L/H（ΣC21-/ΣC22+）指标的详细分析得知其有机质来源以陆生高等植物占主导优势。结合年代数据、有机碳同位素、长链正构烷烃平均链长ACL和C33/(C33+C27)值重建出35.0ka以来银川盆地植被类型以 C3植物为主，并且C3和C4植物的相对比例变化主导受温度制约，而木本和草本植被的演化主要受控于水分条件。 |
| 英文摘要: |
| By the aid of GC method, n-alkanes have been identified in lacustrine sediments from the Binggou profile of the Yinchuan basin, Ningxia, to characterize the palaeovegetation types and evolutions in arid and semi-arid regions. The results show that the n-alkanes with carbon numbers ranging from C15 to C34 exhibit different distribution patterns. Most samples show a single peak with high carbons (C29 or C31 in particular) and have an odd-over-even carbon number predominance, while others have double peaks (the first peak is lower homologue and the second peak is high carbon). The distributions of n-alkanes, CPI and L/H values show that the organic matter in the Binggou profile primarily comes from terrestrial. According to OSL sequence, organic carbon isotope, ACL, and C33/(C33+C27), the relative contents of C4 plants and the evolution of herbs and woody plants have been reconstructed in the study area since 35.0ka. As a result, C3 plants in the Yinchuan basin have great dominance and the changes of C3 and C4 plants are constrained by temperature, while the evolution of woody and herbaceous vegetation is mainly controlled by moisture. |
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