• 责任者：Zhang Zhongliang (Shaanxi Industrial and Trading Company of Minerals ; Xi’an 710054 ; China) ; Zhao Qiang
• 刊名：Geology of Shaanxi
• 出版年：2013
• 卷期：31(2)
• 关键词：延安组 ; Yanan Formation ; 沉积体系 ; depositional system ; 聚煤规律 ; coal accumulation regularity ; 鄂尔多斯盆地 ; Ordos Basin
• 页码：p.37-43
• 图表：1 illus., 14 refs.
• 分类号：0803
• issnNo：ISSN1001-6996
• isbnNo：CN61-1150/P

     Based on the data recently obtained from drilling and logging in Dingbian area and fol- lowing sedimentology, detailed study on the sedimentary system, sedimentary micro phases and coal accumulation has been commenced. Sedimentary systems featured in braiding and curving fluvial deposition are developed well in the first and fourth sections of the Yan＇ an Formation, in which coal forming activities are poor in the braiding fluvial deposition due to its loitering features, but rel- atively well in flood plain and swamp of curving fluvial deposition. Coal forming activities in fluvial deposit systems are generally poor, in which coal seams are featured in big changes in thickness, in- stable horizons and multiple bifurcation or coalition with complex textures. Delta sedimentary system and delta plain peat bog developed well in the second and third sections of the Yan＇ an Formation and formed favorable environment for coal formation, in which coal seams are stable in thickness and horizons, simple in texture and wide distribution, forming important sedimentary systems for coal formation in this area and even the whole Ordos Basin.