摘要
通过对塔里木西南缘含煤盆地侏罗系内沉积物的厚度、岩相、沉积相及其组合分带特征研究,结合岩石(层)结构、构造、矿物成份、古生物、垂直层序以及空间形态等成因标志,进行沉积相分析.总结了含煤盆地古地理类型属于内陆山间盆地型的山间湖盆亚型,聚煤规律为富煤带,即相当于煤层聚集带,富煤中心与凹陷中心一致,煤层累计厚度与地层厚度呈正相关关系.另一规律是砂泥岩比值低的地区即为成煤有利地带,累计厚度与砂泥岩比值呈负相关关系.
Analysis of sedimentary facies of the Jurassic sediments of coal-bearing basins at the southwestern margin of Tarim basin is conducted by statistic of sedimentary thickness, lithofacies, sedimentary facies and assemblage zonation in couple with genetic marks such as stratigraphic association, structure, mineral compositions, fossils, vertical sequence and dimensions. The ancient structures control the coal-bearing formations through generating a depression for coal accumulation. The formation of the Jurassic coal-bearing rocks in the study area is accordingly controlled by structures. The narrow sedimentary basin in the study area is controlled by Tiekelike fault and Maigaiti slope, as well as Western Kunlun northern margin fault. The basin is 揝?shaped in general, with the western section extending NNW, and the eastern section nearly EW. The formation of the basin is thus closely related with the structures. The Jurassic coal accumulation basins include three sub-class basins, i.e., Keziletao basin, Yecheng-Hotan basin and Buya basin. The sedimentary thickness, lithofacies, sedimentary facies and assemblage zonation demonstrate that the three basins belong to intramontanous lake basin type. All basins demonstrate characteristics of vertical sequences formed in an intramontanous lake basin condition. Sections of coal bearing rocks show repetitions of lacustrine facies, swamp facies and peat swamp facies, among which lacustrine facies is dominant. The coal accumulation took place earlier in the west and later in the east. The coal enrichment shows an evident spacial distribution characterized by conformity of the coal enrichment centre with the depression centre. The total thickness of coal beds has a positive relationship with the stratigraphic thickness, mainly marked by great thickenss of the Jurassic. Additionally, areas of low sandstone-mudstone ratio are favourable for coal generation. In another word, the total thickness shows a negative relationship with the ratio of sandstone and mudstone. It is predicte
出处
《新疆地质》
CAS
CSCD
2002年第1期67-71,共5页
Xinjiang Geology
关键词
塔里木盆地
含煤盆地
聚煤规律
富煤带
凹陷中心
砂泥岩比值
含煤岩系
沉积相
空间形态
southwestern Tarim basin
coal-bearing basin
coal accumulation regularity
coal enrichement zone
depression centre
sandstone-mudstone ratio
