胶莱盆地下白垩统莱阳组沉积作用和沉积演化

根据沉积学标志和构造演化史。将胶莱盆地莱阳组阮积作用的演化分为六个阶段:(1)遣仙庄段时期,该盆地尚未发育成一个统一的坳陷,只在南部和北部形成了两个凹陷.湖水是一个浅一探一浅的发展过程.形成了扇三角洲、风暴和浊流的沉积.(2)止凤庄段时期发生了较大规模的水退,尤以北部更为强烈.以干旱一半干单气侯背景下的红层沉积为特征.(3)马耳山段时期构造运动趋于缓和.盆地内外地形高差变小.具高成熟度的稳定型浅水沉j艮(4)水南段是盆地发育的点盛时期.气侯转为湿热,湖面水位高.构造明显控制着沉积.发育了四大沉积区.(5)龙旺庄段时期构造趋向活动,气侯向半湿热一半干旱方向转化;南、北沉积重新出现差异.(6)曲格庄段时期构造运动更为强烈,南部已抬升;北部及断裂带发育活动型陆上沉积.

SEDIMENTOLOGY AND SEDIMENTARY EVOLUTION OF LOWER CRETACEOUS LAIYANG FORMATION IN JIAOLAI BASIN

In light of petrology, sedimentary structures and geochemistry as well as the basin' s tectonic history, the sedimentary evolution in the Jiaolai Basin can be divided into six stages. (1) The basin was not unified and only two seperated depressions existed in the southern and the northern parts during the time of the Xiaoxianzhuang Member. Water depth changed from shallow, through deep to shallow, and a complete cycle of fan delta. storm and turbidite was deposited. (2) A large-scale regression, especially in the northern part, took place during the time of the Member when red beds developed typical of arid to semi-arid climatic settings. (3) Tectonic activity tended to be gentle and the topographic difference became smaller in the Basin. The shallow-water deposits of high maturity dominated in the Maershan Member. (4) The Basin was most active during the time of the Shuinan Member when the climate was wet and tropical. The lake was of high-stand. And tectonics had obviously controlled sedimentation. Four major depositional areas were recognized. (5) Tectonic activity tended to be active during the time of the Longwangzhuang Member. The climate became semi-wet tropical to semi-arid. The depositional difference between the south and the north appeared again. (6) Tectonic activity became even stronger during the time of the Qugezhuang Member, and unstable terrestrial facies dominated in the north and the faulting zone.