元谋盆地河湖相沉积物磁性地层学研究综述

A review of magnetostratigraphic studies of the Yuanmou sequences

元谋盆地河湖相沉积物分布广泛,沉积连续性好,富含古人类和哺乳动物化石,是进行磁极性地层学研究和探讨西南季风演化与转型、早期人类迁徙、哺乳动物扩散与交流的理想材料.本文对已有的磁性地层学研究作了较系统的总结与分析,发现造成对元谋人生活年代和盆地形成与演化过程的争议,主要是由于过去的磁性地层学研究所涉及的采样间隔太大和实验室测试条件不足等诸多因素的影响.这是未来元谋盆地研究必须注意的问题.

The Yuanmou Basin in southwestern China is renown for well-developed, late Cenozoic fluvial-lacustrine sequences containing Yuanmou H. erectus and abundant mammalian fossils. They are excellent archives in views of the magnetostratigraphic study for dating the evolution of Indian monsoon, the migration and dispersal times of early human, the exchanges of mammalian in different regions and climate settings in East Asia. In the past four decades, a series of paleomagnetic works were carried out to determine the living age of Yuanmou H. erectus and various age estimations were documented. Here we review the paleomagnetic results of Yuanmou sequences in literature and find existing uncertainties on the age of Yuanmou H. erectus and exact timing of the formation process of the basin are due to the low-resolution of sampling, magnetic experiments and so on. We stress that high-resolution magnetostratigraphic studies in combination with lithostratigraphy and biostratigraphy are necessary in future to obtain reliable age controls of those Yuanmou fossils and the evolution process of the Yuanmou Basin.