摘要
用GC-MS分析了陕西渭南阳郭剖面S0-L1-S1层段代表性样品的链烃组分与分布。古土壤和黄土亚层中正烷烃呈不对称双峰分布，前组峰位于C16-C24，主峰为C18（WN48样号为C20）。后组峰（C25-C37）高于前组峰，主峰为C31，CPI值为2-4。检测到5个系列的支链烷烃和一个系列的单烯烃。弱古土壤化层（L1-2，L1-4）正构烷烃前组峰几乎没有，CPI为5-6，支链烷烃及烯烃含量相对最低，表明该层形成于湿冷气候。还讨论了影响黄土地区古气候演变的冷湿气源。
Detail studies have been conducted on the GC-MS of chain hydrocarbon isolated from the Weinan loess section (S0-S1) in Shaanxi Province, China. Two Peaks of normal alkanes, the maximum at C18(C20 in WN487) and C31 (C31＞C18), observed from the paleosol layers (S0, S1) and loess layers (L1-1, L1-3, L1-5), the values of ∑C22- /∑C23+ are about 0.2-0.6,and CPI 2.5-4.0; whereas in the tWo weakly developed paleosol layers (L1-2, L1-4 ), a single Peak of alkanes is evident (the maximum at C31) with high CPI (5-6) and lower ∑C22- / ∑C23+ values (less than 0.2).Five series of branched alkanes and one series of n-alkenes were found in this section.The contents of branched alkanes and alkenes are lower in the two weakly developed paleosol layers than those in the other layers. The results show that the weakly developed paleosol layers may formed in cold and humid climatic condition. The source of cold-humid paleoatmospheric current has been discussed in this paper.
出处
《地球化学》
CAS
CSCD
北大核心
1998年第2期180-186,共7页
Geochimica
基金
国家自然科学基金!49272125和49291100-4
关键词
黄土剖面
链烃化合物
弱古土壤化层
古气候
陕西省
loess section, chain hydrocarbon, weakly developed paleosol layer,paleoclimate, Shaanxi Province
