山西襄汾大柴更新统剖面划分的新观点  

A new stratification of the Dachai Pleistocene section,Xiangfen,Shanxi China

作　　者：李斌[1] Reidar Lovlie 苏朴[2] 樊行昭[2] 

机构地区：[1]Department of Earth Science,University of Bergen [2]太原理工大学地球科学与工程系,太原030024

出　　处：《地球物理学报》2008年第4期1040-1047,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40274015);山西省自然科学基金(20011026);山西省留学基金(01-28);挪威国家助学金资助

摘　　要：对山西襄汾丁村文化遗址群内大柴剖面进行的磁性地层学研究表明,松山与布容的极性界线(M/B)出现在距剖面顶部45 m处;磁化率对比结果显示。此位置正好与S8上部对应.由这种极性和磁化率的对应结果可推断,下、中更新统(Q_1/Q_2的地层分界也应在距剖面顶部45 m处的S8上部,而不是传统上认为的Q_1/Q_2的地层分界,在距剖面顶部80 m处.这种以古地磁学为基础的新的划分方案,对丁村遗址群的对比以及丁村遗址年代的最终确定都有重要的指示意义.根据其沉积环境和地层特征推断,采样部位下部的磁化率低值带应为水成黄土.而岩石磁学研究结果显示.磁铁矿、赤铁矿和热不稳定性磁赤铁矿是大柴剖面沉积物中主要的磁性矿物;磁铁矿和赤铁矿同为高温稳定性磁性载体.The magnetostratigraphic study on the Dachai section which is located in the Dingcun Paleolithic sites of the Xiangfen County, Shanxi province reveals that the polarity boundary between the Matuyama and Brunhes appears at about 45 m depth of the section. Magnetic susceptibility （MS） correlation result shows that this 45 m-depth position is right in the upside of S8 layer. Consequently, a conclusion can be drawn that the stratigraphic boundary between the Early Pleistocene （Q1） and Middle Pleistocene （Q2） should be at the 45 m depth, not the traditionally suggested 80 m. This new division plan based on the paleomagnetic studies has significant meanings to correlations among the Dingcun Paleolithic sites and final determination of the age of Dingcun group. At the lower part of the Dachai section MS is characterized by relatively low values and variations. According to its deposition conditions and sediment characteristics, the authors think this sediment is loess formed in water. At the same time, the rock magnetic results demonstrate that magnetite, hematite and thermal-unstable maghemite are the most important magnetic minerals in the Dachai sediments. Magnetite and hematite both are the high-thermal-stable magnetic carriers.

关 键 词：丁村遗址 临汾盆地 更新统 磁性地层 大柴剖面 

分 类 号：P318[天文地球—固体地球物理学]