新疆准噶尔盆地南缘八道湾组沉积特征与聚煤规律分析

Sedimentary characteristics and coal-accumulation pattern analysis of Badaowan Formation in southern margin of Junggar Basin,Xinjiang

根据经典层序地层学和现代沉积学的基本原理,在综合研究钻井、测井、露头、岩心及古生物资料的基础上,分析了准噶尔盆地南缘八道湾组的沉积特征和聚煤规律:对单井进行了层序地层分析,提出准南侏罗系八道湾组的层序划分方案,将八道湾组分为两个具有完整三分结构的层序SQ1和SQ2(与煤田八道湾组下段和上段一一对应);根据连井剖面,建立了八道湾组层序地层格架;在此基础上,结合盆地地质条件,进行了各体系域的沉积相平面分析;最后分析了聚煤规律,表明煤田主力煤层主要发育在低位体系域的末期和高位体系域早期,三角洲平原区是聚煤的最佳场所,对下一步煤炭勘探区的确立具有一定的指导意义。

Using theories of classic sequence stratigraphy and modern sedimentology,the authors analyzed the data of drill holes,loggings,cores and palaeontology with the purpose of investigating sedimentary characteristics and coal accumulation of the Badaowan Formation in the southern margin of Junggar basin.Based on sequence stratigraphic analysis of the single well,the authors divided Badaowan Formation into two sequences,namely SQ1 and SQ2,both of which have the tripartite structure,corresponding respectively to the lower and upper segment of Badaowan Formation in the coalfield.According to the well-connecting profile,the authors established sequence stratigraghic framework,then made a plane analysis of the sedimentary facies of each system tract,and finally analyzed the coal accumulation.It is found that the principal seam of the coalfield developed mainly at the last stage of LST and the initial stage of HST,and the delta plain area is the optimum place for coal accumulation.These results will certainly provide some guidance for the further establishment of coal exploration area.