云南镇安新生代盆地含煤沉积特征

在云南龙陵镇安狭长的山间盆地内,发育着一套以粗碎屑岩为主并含巨厚褐煤层的含煤建造,外表根像河流成煤环境,为此颇有争议。本文通过对该区成煤期构造、气候、植物、水文条件及其地理环境的研究分析,认为此粗屑物质并非通常所说的河流沉积物,是大量边缘互相重量入湖的冲积扇沉积,是个特殊的扇湖成煤环境。由于盆地小,相分异差,搬运短,含煤建造和湖沼是以粗碎屑岩为主。故它不同于国内外一般扇间湾和扇三角洲平原成煤。

THE CHARACTERISTICS OF THE COAL-BEARING DEPOSIT IN THE CENOZOIC BASIN AT ZHENAN IN YUNNAN

A set of coal-bearing formation inluding very thick brown,oal beds and dominant macroclastic rock is developed within the narrow-long intermountain basic in Zhenan, Longlin, Yunnan. It looks like the river swamp deposit in appearance, and adispute arises. On the basis of re- search and analysis on the structare, paleoclimate, paleobotany, paleohy- drologic condition and paleogeographic environment during the period of coal formation in this region, it is considered that the macroclastic materials will be the deposit of alluvial fan with front margins one upon another into lake instead of the river swamp as is often said. It is a special fan-lake environment of coal formation. Seeing that the basin is small, the differentiation of coaly facies is not obvious and the tran- sportation distance is short, the macroclastic rock will become the main sediment in the lake swamp. Such a coal formation environment is dif- ferent from those in delta plain and coves between fans at home and abroad.