Abstract: The Bohai Bay Basin is bordered by the Jiaoliao uplift in the east, the Taihangshan uplift in the west, and the north and south are respectively limited by the Luxi uplift and the Yanshan fold belt. The overall shape is irregular rhombus with an area of about 20×104 km2, which is a Cenozoic fracture. The valley basin is superimposed on the large superimposed (or residual) basin on the pre-Cenozoic craton basin, and a large number of buried hills are developed in the pre-Cenozoic basement. In view of the low level of basic geological research on buried hills in the Bohai Sea, the basic petrological data that can be accessed publicly so far is very scarce, and repeated petrological work is constantly being carried out. For this purpose, this paper collects 201 pieces of Archean buried-hill metamorphic granite and its overlying Paleogene Kongdian Formation glutenite rock flakes in Bozhong Sag, Bohai Bay Basin, divided into two parts, 61 granite flakes and 140 clastic flakes. It is revealed that the deep buried hill reservoir in the Bozhong 19-6 (ie BZ19-6) structural belt is a pan-buried hill reservoir system composed of the main body of Archean buried hill metamorphic granite and the overlying Paleogene Kongdian Formation glutenite. A multi-layered reservoir structure consisting of glutenite pore zone + buried hill weathering crust dissolution fracture zone + inner fracture zone tight zone is formed, and the reservoir genes are complex and diverse in types. The dataset records the sample collection location, stratigraphic age, and rock name. The granite part shows that the buried hill mineral assemblage is dominated by dark minerals such as quartz, feldspar, and a small amount of biotite, and the fracture period, filling type, and hole ratio are recorded in detail. The clastic rock part records the composition of the glutenite of the Kongdian Formation of Paleogene and the content of miscellaneous base. Through systematic microscopic rock section research, the differential development of fractures caused by lithological changes in the BZ19-6 pan-buried hill reservoir system has been clarified, and the reservoir dissolution and transformation effects of lithological fluids have been identified, which is a further exploration for oil and gas in the Bohai Sea buried hill. It lays the foundation of petrology. In addition, it provides valuable petrological materials in the Bohai Sea for in-depth research on the destruction of the North China Craton.
Keywords: Bohai Bay Basin; buried hill; granite; glutenite
