小江流域第四纪泥石流期的初步划分  

PRELIMINARY DIVISION OF THE QUARTERNARY DEBRIS FLOW PERIODS IN XIAOJIANG BASIN, YUNNAN

作　　者：史正涛[1] 张林源[2] 杜榕桓[3] 

机构地区：[1]中科院兰州冰川冻土研究所 [2]兰州大学地理系 [3]中科院成都山地灾害与环境研究所

出　　处：《自然灾害学报》1994年第2期97-104,共8页Journal of Natural Disasters

基　　金：中国科学院东川泥石流观测研究站资助课题

摘　　要：根据不同时期泥石流堆积体分布的地貌部位、岩相特征、堆积体及其上发育的古土壤的化学特征、孢粉组合和部分绝对年代资料,将小江流域的泥石流初步划分为时间尺度较大的五个强盛期。各期泥石流都是暴雨型泥石流。由于本区第四纪以来一直属于季风气候区,因此上述大尺度活动周期主要受全球冰期与间冰期中本区干温和湿热气候变化的制约。Xiaojiang River Basin in Northeastern Yunnan Province not only developed extensively modern debris flow but also distributed wide-ranging of Paleo-debris-flow. Paleo-debris-flow mainly distributed in Xincun Basin, middle reach of Xiaojiang. According to the distributive location of different period of debris flow sediments, petrographical facies feature and fossil soil characters, sporo-pollen multiplicities and some absolute age documents, this paper prelimilarily classifies the debris flow in Xiaojiang into five relative long-term active periods, they correspond to the 19th, 13th, 9th, 5th and 1st stages of deep maraine, layer oxygen isostope curve respectively. Each debris flow also exists several sub-periods. This region is always located at the monsoon climatic region since the Quarternary, thus the long term debris flow periods are confined by the global glaciation and inter-glaciation climate fluctuation. The widespreading of modern debris flow is due to the post-glacial periodic climate, the enhanced human activities and the unreasonable reclamation of the mountain enlarge the distribution range and intensity. The multi-planation surfaces lie in different height because the two Planation surfaces are de-composited by later fault movements. This region is in the uplift process since the Mid-pleistocene Epoch.

关 键 词：第四纪 泥石流期 环境 

分 类 号：P642.23[天文地球—工程地质学]