新疆伊犁盆地伊宁凹陷中下侏罗统沉积相分析

Sedimentary Facies Analysis of Middle--Lower Jurassic in Yining Depression of Yili Basin, Xinjiang

以沉积学理论为指导，利用野外露头、钻井岩心等资料，研究伊宁凹陷中下侏罗统沉积相特征，分析沉积体系对聚煤的影响。认为研究区主要发育冲积扇、扇三角洲和湖泊3种沉积体系类型。八道湾组和西山窑组湖扩体系域至高位体系域时期，滨岸平原和扇三角洲平原上广泛发育泥炭沼泽，为煤炭的聚集提供了有利条件。

Based on modem sedimentology theories, along with the the field outcrops, drilling borehole, the sedimentary facies of Middle- Lower Jurassic of the Yining depression is established, and the coal- accumulating regulation are dis- cussed under the sedimentary system. Alluvial fan facies, fan delta facies, and lake facies were the main sedimentary fa- cies during the Early-Middle Jurassic in the study area. Badaowan and Xishanyao Formations were the main coal-bearing formations, Peat swamp were widely developed in coastal plain and fan delta plain during the late EST and early-middle HST period.