滦河冲积扇结构和沉积环境  

STRUCTURES AND SEDIMENTARY ENVIRONMENTS OF THE ALLUVIAL FAN OF THE LUAN RIVER

作　　者：高善明[1] 

机构地区：[1]中国科学院地理研究所

出　　处：《地理研究》1985年第1期54-62,110,共10页Geographical Research

摘　　要：本文根据河谷阶地对比,沉积相特征,孢粉组合,石英砂表面微结构组合和^(14)C、古地磁年龄数据,探讨滦河(东部)冲积扇的形成时代、沉积环境和沉积速率,为研究唐山山前平原地下水储存条件提供一些论据。The Luan River is a medium-size river carrying heavy sedimentary load.Its water flow and sediments mainiy come from the mountainous regions of Yan-shan Mts.Controlled by the tectonic fault, the middle reaches of the Luan River change its course and form branches. Since Quaternary the course of the Luan river in Qianxi Bend has branched into the Late and the Middle-Early pleistocene alluvial fan systems in the east and the west of tangshan town.The eastern fan formed in the late pleistocene is a larger one which can be divided into three areas. The proximal area stretches right to the mountainous mouth; the mid-fan area is in the south of Zhaocun (where there are many ero-sional surfaces and lag sediments of the river in the stratum.It shows that the hydraulic conditions of scouring and silting have greatly changed their courses, The distal area where the deposited debris transforms to finer grains and stratigraphic series tends to be in Steady state, is situated in the south of Dingliuhe. Marine stratum is found on the lower plain in the south of Yangge-zhuan and there the sedimentary facies changed from alluvial-pluvial to alluvial-marine deposits.In the formation period of the alluvial fans, the sedimentary environments hand involved time and again fluctuations of the climate.The semi-arid climate is the most favuorable condition to develop alluvial fans, because in this period the rate of sediment deposition is very fast.

关 键 词：滦河冲积扇 沉积环境 沉积物 分选 洪积相 孔深 迁西 小砾石 侵蚀面 棱状 

分 类 号：P9[天文地球—自然地理学]