吐哈盆地西山窑组第二段岩相古地理和聚煤作用

LITHOFACIES PALAEOGEOGRAPHY AND ITS CONTROL ON COAL ACCUMULATION FOR THE SECOND MEMBER OF XISHANYAO FORMATION IN TURPAN-HAMI BASIN

摘要: 吐哈盆地烃源岩主要是早侏罗世八道湾组和中侏罗世西山窑组的煤和碳质泥岩。本文对该盆地主要含煤段——西山窑组第二段沉积期岩相古地理进行了分析,编制了各种图件,总结出该期岩相古地理特征并分析了聚煤作用的控制因素。烃源岩主要形成于三角洲间湾和下三角洲平原,这里沉降幅度中等且陆源供给受到限制。

Abstract: The source rocks of Turpan-Hami Basin are preserved in the Early and Middle Jurassic strata,which include Badaowan Formation(J 1) and Xishanyao Formation.This paper discussed the lithofacies paleogeography during deposition of the second member of the Middle Jurassic Xishanyao Formation.The pictures are graphed.The features of the lithofacies paleogeography are summarized and the control factors of coal accmulation are analyzed.The source rocks are mainly formed in interdeltaic bay and lower delta plain environments where intermediate subsidence is kept and there is little input of the sediments from land.