北京房山县山前平原古水系及其特征初步研究

A PRELIMINARY RESEARCH ON THE ANCIENT REVER SYSTEMS AND ITS FEATURES OF THE PLAIN IN FRONT OF THE MOUTAINS IN FANGSHAN COUNTY OF BEIJING

本文研究的内容是周口店北京猿人遗址综合研究中的一部分.根据本区大量钻孔资料复原了第四纪基底地形.它呈古丘陵地形的形态特征.按覆盖在古丘陵地形不同部位上的沉积层的时代,确定出更新世各相应时期地形面的位置.从而圈定出各时期水系的位置,分别绘制出中更新世及晚更新世早期水系图.最后,分別讨论了本区中更新世以来各时期的水系特征,及水系变迁规律,并建立起北京西山山前平原自第四纪初期以来的地貌发育模式.

This paper is a part of the synthetical study of the relics of Homo erectus pekinensis in Zhoukoudian. The Quaternary basal landforms which presented a view of hilly lands have been remodeled by the drill hole geological records in this area.According to the geological ages of the sedimentary deposits covered on the different parts of the ancient hills, the position of the corresponding topographic surface in each epoch of Pleistocene is determined. The border of the river systems has been defined and the maps of the river systems in the Middle Pleistocene and in the early stage of the Late Pleistocene have been drawn. In this study, the characteristics and changes of the river system in the above mentioned geological period have been discussed. The model of the geomorphologic development since early Quaternary in front of the Western Mountains in Fangshan County of Beijing has been set.