【作者】 李伟；

【导师】 林玉祥；

【作者基本信息】 山东科技大学 ， 矿产普查与勘探， 2010， 硕士

【摘要】 本文通过综合采用地震、测井、录井、古生物等分析手段,对松辽盆地白垩世岩相古地理进行了系统的研究。研究表明松辽盆地早白垩世主要发育火山岩、河流、滨浅湖、三角洲和冲积扇沉积,晚白垩世主要发育深湖—半深湖、滨浅湖、三角洲、河流和冲积扇沉积。进一步研究认为,断裂构造是控制盆地内沉积特征变化的主要因素,区域构造背景是盆地沉积、沉降中心迁移的诱因。盆地的北北东向和北西向两组基底断裂控制了早期断陷盆地的分布,而且由于其对盆地沉积的控制作用,盆地的沉积轴向为近北北东向,物源和水系主要沿两组断裂展布。在沉积和构造研究的基础上,结合盆地的古物源、古气候、古湖泊的平面变化等研究,对松辽盆地白垩纪岩相古地理有了系统的认识。早白垩世早期火石岭组至营城组沉积时期主要形成了火山碎屑岩,以相互分割的小型湖泊为主要特征；登娄库组沉积时期盆地形成统一的沉积区,沉积了一套砂泥岩组合；到泉头组沉积时期,除少数地区外,已经形成统一的湖泊沉积体系；青山口组沉积是盆地整体下沉,湖盆的首次扩张,主要发育垂直于盆地长轴发育的扇三角洲体系和辫状河三角洲体系；到姚家组沉积时期,盆整体抬升；嫩江组沉积时期是松辽湖盆由极盛转为逐渐衰亡的时期；四方台组一明水组沉积时期,沉积中心西移,中央坳陷区以细碎屑岩沉积为主。该期间盆地经历了断裂活动由强到弱,古水域由小到大,古湖盆由分割到统一的变化过程,沉积相整体呈现出东西分带、相带分布不对称的沉积格局。更多还原

【Abstract】 This paper stuied lithofacies palaeogeography of the Cretaceous in Songliao basin,by using seismic, well logging, paleontology and other methods. The research shows that the basin developed volcanic rocks, rivers, shallow lake, delta and alluvial fan deposits in Early Cretaceous, and semi-deep to deep lake, shallow lake, delta, river and alluvial fan deposits in late Cretaceous. In the further study, also shows tectonic controls the basin evolutionary and regional tectonic is the main factor causing the subsidence center and depocenter of the westward movement. NNE and NW-trending basement faults controlled the distribution of the early rift basin, but also because of its effect on the control basin, the sedimentary axis is nearly NNE, source and river systems along these faults.Base on this foundation, combined with the sediment source, paleoclimate, and lake level changes, lithofacies palaeogeography of the Cretaceous in Songliao basin is described. in the Early Cretaceous from Yingcheng Formation to Huoshiling Formation is mainly developed pyroclastic rocks and deposited in small lakes.The basin merged into one sedimentary basin area and formed a suit of sand and mud stone. Untill the Quantou Formation,it has formed a unified lake sedimentary system except for a few areas. The basin is subsidenced and the lake is expaned during Qingshankou Formation, and developed fan delta system and braided delta system along basin axis.During Yaojia Formation, it is uplifted. It turned into smaller from Nengjiang Formation. Depocenter moved to west and center depression deposited fine clastic durning Sifangtai Formation to Mingshui Formation. The basin has experienced the fault activity from fierceness to light, the paleo-lake from small to large, the basin from the division to the unity, and sedimentary facies were divied into east and west part, distribution shows pattern of asymmetry.更多还原