“Source-to-Sink” system is a hot topic in recent sedimentology research.The eastern slope of Chengdao

which constitutes a complete “Source-to-Sink” system together with Chengbei low salient and its surrounding depositional areas

is a transitional slope zone from Chengbei low salient to Shanan and Bozhong Sags

and located in Bohai Bay Basin.Based on the core

logging and 3D seismic data

we defined the basement rock types of provenance

reconstructed the palaeogeomorphology of the 2

nd

member of Dongying Formation(Dong 2 member)

made a quantitative analysis of elements in the “Source-to-Sink” system

finely mapped the sand bodies within the depositional area

and established the coupling model of the “Source-to-Sink” system in the eastern slope of Chengdao.The results show that the isolated flood sublacustrine fan deposits

being predominant in the Dong 2 member

are all sourced from Chengbei low salient

and their basement rocks are composed mainly of clastic and pyroclastic rocks.The distribution patterns and scales of sand bodies in depositional areas are mainly controlled by source type

relief

area of catchment

size of transportation pathways

slope break zone

palaeomorphology of depositional area and so on.Among them

the total volume of sediments imputing into the depositional area is closely related to the relief and the catchment area.The larger the relief(averaging at about 1 280 m)and catchment area(averaging at around 7 km

2

)are

the larger the scale of the fan system will be;on the contrary

the fan system contracts accordingly.In addition

the palaeogeomorphology in the depositional area and slope break zone also exert an important control on the size of fan system.Two types of slope break zones were recognized in this study

namely the topographic and fault slope break zones.The angles of the slope break zones range between 3.9° and 9.8°

and show a positive correlation with both the fan body thickness and area.Meanwhile

the size of transportation channels(width/depth ratio and cross-sectional area)also determines the distribution characteristics of sand bodies.In summary

the elements in the “Source-to-Sink” system in the study area are relatively stable during the deposition of the study interval.Finally

we proposed a multi-factor coupling model of source areas with multiple lithologies(provenances)-channels of paleo-ravines or fault troughs within provenance-transportation pathways of topographic/fault slope break zones(transportational area)- isolated flood sublacustrine fan(sinks).This model establishes the relationship between the size of sand bodies and their provenances

and provides potential implications for predicting favorable sand bodies in future oil and gas exploration.