Characteristics of zircon in the Huagang Formation of the ccentral inversion zone of Xihu Sag and its provenance indication

The Huagang Formation of the central inversion structural belt in the Xihu Sag is one of the most significant exploration areas of the East China Sea Basin. But currently, the research of the provenance system of Huagang Formation is relatively weak, which severely limits the studies of sand-body distribution and reservoir characteristics. The provenance characteristics of sandstones in the Huagang Formation were studied based on the zircon U-Pb dating of core samples and combined with seismic reflection features. The results show that the large sand body of Huagang Formation is composed of sandstone of three ages, which are Precambrian (accounting for the largest proportion), Paleozoic and Mesozoic. The large sand body sourced from the Precambrian in the Hupijiao reef in the north, and extended to the south through the sag. Affected by the Haijiao reef in the west and the Diaoyu Islands folding zone in the east, the provenance from the north was dominant while those in the east and west were secondary.