兰州—民和盆地第三纪沉积特征及环境

在野外区域地质调查的基础上 ,通过岩性、沉积构造、古流向、垂向序列、沉积体三维形态和组合及室内粒度分析、扫描电镜分析等 ,于研究区第三纪地层中识别出了三角洲相、三角洲平原相、河流相、湖泊相、冲积扇相及风成砂丘。系统地研究了盆地的垂向充填序列 ,并且就对应的环境演变进行了较详细的探讨。

Tertiary sedimentary features and environment of the Lanzhou-Minhe basin

On the basis of the fieldregional geological surveys and through studies of the lithology, sedimentary structures,paleocurrent direction, vertical sequence and three-dimensional shape and association ofsedimentary units and grain-size analysis and scanning electron microscope analysis, thedelta facies, delta plain facies, fluvial facies, lacustrine facies, alluvial facies andeolian sand dunes are distinguished in Tertiary strata of the Lanzhou-Minhe basin. Theauthors made a systematic study of the vertical infilling sequence of the basin. Moreover,the corresponding environmental evolution is discussed in detail.