摘要
在对准噶尔盆地早-中侏罗世含煤岩系进行层序地层分析的基础上,对聚煤期古地理特征及其与聚煤作用的关系进行研究。结果表明:该盆地早-中侏罗世含煤岩系形成于河流-三角洲-湖泊沉积体系,共发育3个三级层序,分别对应于八道湾组(J1b)、三工河组(J1s)及西山窑组(J2x);准噶尔盆地从层序I和层序III,先后经历了沼泽化(层序I)—湖化(层序Ⅱ)—沼泽化(层序III)过程;在最大湖泛面附近的湖侵体系域末期和高位体系域早期,较快的可容空间增加速率与泥炭堆积速率相平衡,从而有利于厚煤层的聚集;该期成煤环境多样,层序I和层序III的河流泛滥平原沼泽、三角洲平原沼泽及滨浅湖中均有厚煤层形成,但尤以三角洲平原沼泽成煤最优。
Analysed the sequence stratigraphy and palaeogeography of the early and early middle Jurassic coal meas- ures in the Junggar Basin, northwestern China. The controls of the palaeogeography and sequence stratigraphy on the coal accumulation in this basin was discussed. The results show that, the coal measures were formed in a fluvial-delta- lacustrine sedimentary system, and a total of 3 third-order sequences were developed, corresponded to Badaowan For- mation（ Jib ）, Sangonghe Formation （J1s） and Xishanyao Formation （J2x）. The Junggar Basin had experienced the swamping （Sequence I）--lake flooding （Sequence II）--swamping （Sequence III） processes. The thick coal seams were developed at the late transgressive systems tract and the early highstand systems tract and near the maximum flood surface ,when the rate in creation of accommodation kept balance with the peat accumulation rate. Sequence I and sequence III＇s coal-forming environments are floodplain swamp, the delta plain and the shallow lake, especially delta plain best.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2013年第1期114-121,共8页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2013CB227901)
关键词
准噶尔盆地
侏罗纪
岩相古地理
聚煤作用
层序地层学
Junggar Basin
Jurassic
lithofacies palaeogeography
coal accumulation
sequence stratigraphy
