胶莱盆地中部李党家—马山古凸起白垩纪岩石地层序列及岩相古地理

李党家—马山古凸起为胶莱盆地前莱阳群沉积期凸起,第四系覆盖严重,研究程度较低,一直是胶莱盆地研究的薄弱环节,长期以来未能揭示其地层、构造面貌。本文通过大量地表地质调查和对李党家—马山古凸起之上的胶参2井、胶参3井综合录井资料研究解释,运用层序地层学原理和沉积相分析、岩相古地理研究,对研究区沉积填充序列进行了描述和对比分析,理清了研究区白垩纪地层层序格架,恢复了李党家—马山古凸起白垩纪岩相古地理。李党家—马山古凸起莱阳群沉积期未沉积,青山群沉积期开始沉降,连续沉积了后夼组和八亩地组及王氏群辛格庄组。研究区处于火山洼地中,整体为一套巨厚陆相细碎屑岩沉积,夹少量火山岩—火山碎屑岩沉积组合,其中的火山沉积识别出4期火山旋回。本研究为胶莱盆地原形盆地恢复提供了依据。

Cretaceous lithostratigraphic sequence and lithofacies palaeogeography of the Lidangjia—Mashan paleo-uplift in the central Jiaolai Basin

Objectives:This paper aimed to the petrostratigraphic attribution and lithofacies palaeogeography of the Lidangjia—Mashan paleo-uplift,the central overburden area of the Jiaolai Basin.Methods:The principles of sequence stratigraphy and sedimentary facies analysis,lithofacies paleogeography are used in the study.Based on the study of the lithostratigraphic units,stratigraphic sequences and volcanic cycles of the Upper Cretaceous continental strata in the Lidangjia—Mashan paleo-uplift,the sedimentary framework is established and the lithofacies palaeogeography is restored.Results:The upper continental strata of the Lidangjia—Mashan paleo-uplift is a set of thick Mesozoic continental fine clastic rock deposits with a small amount of volcanic rock—pyroclastic rock deposits.Four stages of volcanic cycles have been identified.The stratigraphic framework has been established in the studied area,restoring the lithofacies palaeogeography of the Laiyang Group,Qingshan Group and Wangshi Group in the Lidangjia—Mashan paleo-uplift.Conclusions:The upper continental strata of the Lidangjia—Mashan paleo-uplift are divided into Houkuang Formation,Bamudi Formation of the Qingshan Group and Xingezhuang Formation of the Wangshi Group.4 stages of volcanic cycles are identified:the Houkuang cycle,Bamudi cycle,Shiqianzhuang cycle and Fanggezhuang cycle.The Lidangjia—Mashan paleo-uplift is a denudation source area in the Laiyang deposition period and has not been deposited.And it began to subside during Qingshan deposition period,and accepted the thick lucustrine deposits.During the Late Cretaceous,the lake in the Lidangjia—Mashan paleo-uplift disappeared and was in a state of denudation.The sedimentary center migrated to the north and south sides.