中国黄土中松山-高斯极性倒转事件记录的空间对比  

The Spatial Discrepancy Records of Matuyama-Gauss Polarity Reversal in Chinese Loess

作　　者：谢兴俊 周卫健[1,2] 鲜锋[1,2] 武振坤[1,2] 

机构地区：[1]中国科学院地球环境研究所∥黄土与第四纪地质国家重点实验室,陕西西安710075 [2]西安加速器质谱中心∥陕西省加速器质谱技术与应用重点实验室,陕西西安710054 [3]中国科学院大学,北京100049

出　　处：《中山大学学报（自然科学版）》2014年第2期121-130,共10页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家重大科学研究计划(2013CB955901);国家自然科学基金(41230525;41203019);黄土与第四纪地质国家重点实验室开放基金(SKLLQG1133)共同资助项目

摘　　要：前人古地磁学研究表明,中国黄土不同剖面中松山-高斯(M/G)地磁极性转换界线记录层位并不一致,有的记录在黄土中,有的记录在红粘土中,这种不一致现象将可能影响到基于古地磁的黄土年代框架的建立及与全球气候记录的准确对比。针对这一问题,选取目前已有的典型黄土剖面中M/G地磁极性转换研究的结果进行了对比分析,并尝试采用磁化率-深度曲线的空间对比来检验不同剖面M/G界线层位记录的差异,结果表明中国黄土中M/G界线均记录在由磁化率-深度曲线所反映的"黄土L33层",说明黄土中M/G界线层位记录不一致的现象可能主要是由于地层划分方案的差异所致。根据这一思想,论文尝试对传统的洛川、西峰黄土地层划分方案进行部分修订,并简要介绍了M/G界线记录的海陆对比差异和未来利用宇宙成因核素10Be示踪M/G极性倒转事件过程的可能性,以期为研究黄土中地磁极性转换过程和确切层位提供一种新方法。Previous paleomagnetic studies have shown that the records of Matuyama-Gauss （M/G）re-versal event in Chinese loess are asynchronous,some located in loess,while the others located in red clay.This phenomenon will partially lead to the uncertainties in reconstructing the chronology of loess and correlating loess climatic proxies with marine sediments.To clarify our knowledge on the M/G reversal in loess,some representative section studies on the M/G reversal are carefully analyzed in this paper,using the magnetic susceptibility-depth curve to synthesize the different sections.Comprehensive results show that M/G reversal is generally recorded in loess L33 layer,suggesting that the asynchronous feature of M/G reversal record in loess is possibly attributed to the different loess stratigraphic division schemes.Ac-cording to this idea,the stratigraphic classification scheme of the classic Luochuan and Xifeng loess is partially modified.Finally,the records of M/G reversal in Chinese loess-paleosol are further compared with that of the marine sediments.The perspective of using 10 Be to trace the M/G polarity reversal in loess is briefly introduced.

关 键 词：第四纪 黄土地层 古地磁极性倒转 M G界线 

分 类 号：P539.3[天文地球—古生物学与地层学] P534.63[天文地球—地质学]