Abstract Based on analysis of gravity anomaly and seismic data, heavy mineral data, clastic rock data and sand body distribution were used to identify the provenance of the Member 2 of Kongdian Formation in Kongnan area, Huanghua Depression, Baihai Bay Basin. Regional Bouguer gravity anomaly field which has important referential meaning for analysis of provenance delineated the topography of Kongnan area. Sand bodies at basin margin and their fan-shaped outlines delineated the macroscopical scope of each provenance. Incised grooves surrounding the depression roughly indicated the locations of the provenances. Progradational reflection configuration on the seismic profiles confirmed the locations of the provenances. Heavy minerals included zircon, tourmaline, rutile, garnet, and magnetite. Heavy mineral assemblages and their variations indicated the directions and routes of detrital materials. Clastics consisted of abundant quartz grains, a small quantity of feldspar grains and little rock debris from the magmatic rock which was the primary source rock type. Located at the directions of southeast, southwest, northwest and northeast of the basin, the provenances were divided into ten sub-provenances at Wumaying, Yesanbo, Shenüsi and so on. These sub-provenances surrounded the lake basin and controlled the formation and distribution of sand bodies during the depositional period of Member 2 of Kongdian Formation in Kongnan area.
|
|