焉耆盆地侏罗纪含煤地层深水成因证据与沉积模式  

DEEP-WATER ORIGIN OF THE MESOZOIC COAL-BEARING STRATA IN YANQI BASIN,NORTHWEST CHINA

作　　者：吴明荣[1] 姜在兴[1] 鲁洪波[1] 蒲晓强[1] 

机构地区：[1]石油大学,山东东营257061

出　　处：《新疆地质》2002年第1期53-57,共5页Xinjiang Geology

摘　　要：新疆焉耆盆地沉积环境研究表明,该盆地侏罗纪煤系具有两种不同的成因环境:即浅水原地环境和深水异地环境.从煤层的产状,与煤共生的泥岩中的有机质类型,与煤共生的碎屑岩的成分、结构、构造和相序等方面论述了焉耆盆地中生界含煤地层深水成因的证据,并建立了深水煤系沉积模式.Yanqi basin is one of the widely developed coal-bearing basins in Northwest China with a pre-Mesozoic basement overlain by Triassic, Jurassic, Tertiary and Quaternary rocks. The Jurassic system, a set of petrol-bearing strata, is considered to have main reservoir and source rocks of the basin. Much has been done on the sedimentary environment of coal measured strata and the coal抯 origin. Environments favorable for coal抯 formation from continent to marine are fluvial-alluvial plain, lake bay and shoal swamp, abandoned delta and fan delta, the inter-distributary of an active delta, coastal marsh and backbarrier-estuarine environment. Coal beds or seams in these environments were originated from shallow water reducing swamps. The core analysis shows that the Jurassic of Yanqin basin is a set of coal抯 series of terrestrial strata, but sedimentary facies indicators do not surport the standpoint of coal抯 shallow water origin. Any other facies markers indicative of shallow water environment have not yet been found, while there are lots of deep-water characters contradictory to traditional standpoint on origin of coal measures, so it is necessary to establish a new depositional model for the deep-water coal seams. In this article, the dimension of the coal beds, the types of organic matter, and the components, structures, textures and facies sequences of the clastic rocks which are associated with the coal beds were taken into account as the evidences of the deep-water origin of the Mesozoic coal-bearing beds, further more a depositional model of coal was proposed. The main features of deep water-formed coal measures have been listed below: (1) The deep-water coal beds have a direct contact with overlying and underlying rocks. Plant root and seat stones, marks of in situ growth and anochtnonous deposition, have not been identified. (2) The colors of mudstone range from deep grey to black. Pyrite can be found in the mudstone which is sometimes interbeded with thin thin silt-fine sand beds and has deformed beddings

关 键 词：新疆 焉耆盆地 煤系地层 深水成因 沉积模式 沉积环境 有机质 

分 类 号：P618.11[天文地球—矿床学]