胶莱盆地下白垩世莱阳群沉积特征研究

Study on Sedimentary Characteristics of Lower Cretaceous Laiyang Group in Jiaolai Basin

根据沉积学标志和构造演化史,认为胶莱盆地下白垩世莱阳群沉积环境以河湖相为主,由2个完整的水进-水退沉积旋回组成。其中,下部瓦屋夼组形成了一个独立的沉积旋回;上部从林寺山组、止凤庄组到曲格庄组组成第二个沉积旋回,该沉积旋回全区发育,反映了胶莱盆地的主要沉积特征。止凤庄组、林寺山组是盆地形成初期,发育冲洪积扇沉积体系。水南组是盆地形成的鼎盛时期,发育三角洲-深湖沉积体系,该组地层暗色泥页岩发育,为较好的页岩气目标地层。龙旺庄组是盆地形成中晚期,发育河流-三角洲相沉积体系。曲格庄组为盆地消亡期,主要为河流相沉积体系。

In light of sedimentary characteristics and tectonic evolution history, Lower Cretaceous Laiyang group deposition in Jiaolai basin is composed of two complete scales of transgression and regression sedi- mentary cycle, of which the lower Wawukuang formation forms a complete sedimentary cycle and the up- per Zhifeng to Qugezhuang formation forms another complete sedimentary cycle, embodies a whole basin development of the whole process. Wawukuang formation, limited distribution, formed during the early stage of basin formation, forms sedimentary system of fan delta, storm and turbidity.Zhifengzhuang and Linsishan formation, formed during early stage of basin formation, develops alluvial fan sedimentary system. Shuinan formation, formed during the peak period of basin formation, develops delta--deep lake sedimentary system. Longwang formation, formed during the middle and late stage, develops lake--delta faces sedimentary system. Qugezhuang group, formed during extinction period of basin formation, develops lake faces sedimentary system.