南堡5号构造东部东三下亚段滑塌浊积岩沉积特征及成因

Sedimentary characteristics and genetic of the lower Ed3 formation fluxoturbidite in the east of Nanpu Structure 5

通过薄片、岩心、测井和地震资料的综合分析,在南堡5号构造东部东三下亚段高位体系域中首次发现滑塌浊积岩。结合古地貌及连井相分析,明确扇三角洲平原—前缘亚相发育于古沟槽区,滑塌浊积岩相发育于古洼槽区。区域地质分析表明,研究区北部发育大型火山群,东三下亚段高位域沉积时期火山活动强烈,火山活动所引发的大地震动是诱发滑塌浊积作用的主要原因。南堡5号构造东三下亚段高位体系域浊积岩是扇三角洲前缘砂体在强烈火山活动作用下发生滑塌的产物。

With a joint use of thin-sections,cores,logging,and seismic data,the fluxoturbidite was first found in the highstand systems tract of the Lower Ed3 Formation in the east part of Nanpu Structure5.Based on the analysis of palaeogeomorphology and cross-well facies,it is dicscoverd that the fan delta plain-front subfacies developed in the rut area,and the fluxoturbidite facies developed in the sag area.Regional geological analysis shows that there are large volcanos in the northern part of the study area.During the highstand systems tract sedimentary period of the Lower Ed3 Formation in the north,the volcanic activity was intense,and the earthquake motion caused by intense volcanic activity was the main reason for the formation of fluxoturbidite.The fluxoturbidite in the highstand systems tract of the Lower Ed3 Formation in Nanpu Structure 5 came from the fan delta front sand body which caused by intense volcanic activity.