民丰洼陷古近系沙三中亚段物源体系研究

对民丰洼陷沙三中 亚段进行了物源体系的研究表明,变质岩、花岗伟晶岩、中基性的喷出岩、基性-超基性侵入岩和沉积岩为主要的母岩类型。研究区存在北、东、南3个主要物源区,其重矿物组合、特征元素比值、岩石组分等.方面存在明显的差异,分别形成了北部的近岸水下扇体系、东部的永安镇三角洲和南部的东营三角洲。随着地层由老变新,东部和南部的沉积边界向盆地进积,而北部物源逐渐萎缩。3个物源区的交汇处为浊积岩的有利探区。

The Es3 Provenance System of Eogene Shahejie Formation in Minfeng Sub-Sag

The study of provenance system includes the clastic composition type and microscopic feature, heavy mineral assemblage, typical element distribution, sands distribution and palaeogeographic framework, etc of Es³ of Eogene Shahejie formation in Minfeng sub- sag. The results show that the metamorphic rock, granite pegmatite, mid-basic effusive rock, basic-ultra basic intrusion rock and sedimentary rock are the main types of parent rocks. There exist NES directions of provenance systems in the studied area where obvious differences in the heavy mineral assemblages, the typical element ratio and the rock composition occur, thus forming the inshore submarine fan in the north, the Yong'an delta in the east and Dongying delta in the south. With the stratigraphic younging, the progradational boundaries of sediments appear towards the basin, with the shrinkage of north provenance system. The intersection area of the three directional provenance systems could be favorable prospecting area of turbidites.