萨拉乌苏河流域钙结核中碳氧同位素特征及古环境意义  

Carbon and Oxygen Isotope Composition of Calcium Nodule and Its Paleoenvironmental Significance in Salawusu River Valley

作　　者：杨劲松 郝瑞祥[3] 王永[4] 

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029 [2]中国地质科学院水文地质环境地质研究所,第四纪年代学与水文环境演变重点实验室,石家庄050061 [3]中核集团核工业北京地质研究院,北京100029 [4]中国地质科学院地质研究所,北京100037

出　　处：《科学技术与工程》2018年第5期13-18,共6页Science Technology and Engineering

基　　金：中国地质大调查(121201106000160914,12120113005600)资助

摘　　要：通过对萨拉乌苏河流域酒坊台剖面中普遍发育的钙结核进行碳、氧同位素分析,结果显示各岩性组中同位素分布特征差异较大,无明显线性关系。利用钙结核中碳同位素值推算了不同岩性组中C_3和C_4植物的相对贡献量,结合孢粉数据,探讨了不同气候条件下植被演变情况,这与邻区的黄土高原研究成果基本吻合。同时,利用氧同位素和温度的经验公式,定量恢复了倒数第二次冰期-末次冰期的温度变化,其中末次间冰期表现为相对温暖的气候特征。总之,利用钙结核的碳氧同位素可作为定量恢复古温度、古植被的一种有效方式,但需要注意与其他指标进行综合对比分析。There are widespread calcium nodules in the lower-middle part of Jiufangtai section in Salawusu River Valley. The results show that carbon isotope and oxygen isotope of calcium nodules are characterized by scattered distribution and big differences in different lithology groups. And then,C4 biomass can be estimated for each calcium nodule by geochemical calculation. Combining with pollen records in the corresponding stratum,the evolution of vegetation cover in the cycle of glacial and interglacial period is discussed,which is similar with the results in the loess plateau. Meanwhile,the paleotemperature can be discussed quantitatively with the conventional formula of oxygen isotope. And the results confirm the last interglacial period is warmer. Therefore,it＇s an effective way to restore temperature and vegetation. But it＇s also important to make comprehensive analysis and compare with another reference material.

关 键 词：孢粉 碳氧同位素 钙结核 萨拉乌苏 古环境 

分 类 号：P534.63[天文地球—第四纪地质学]