Effect of Lake Level Fluctuations on Turbidite Fan Development in Wang 58 Block

In continental rift-subsidence basin, external parameters, such as lake level fluctuations and tectonic movement, have an obvious effect on the development of turbidite fan. Taking the Upper Sha-4 turbidite fan in Wang-58 block as an example, we explain how lake level fluctuations control the development of turbidite fan. Lake level fluctuations cont rol t he development phase of t urbidit e fan through controlling sediment supply. In the study area, turbidite fan develop in Sha-2 and Sha-3 of Upper Chun sub-interval, not in Sha-1 and Sha-4 because the lake level lower down or rise up. Lake level fluctuations also control the type of developed turbidite fan. Tur bidite fan with channel is developed in Sha-3 of Upper Chun sub-int erval. In Sha-2, the slump tur bidite fan without channel is developed because of deep water. In a word, the development of turbidite fan of Upper Chun sub-interval of the Es4 member in Wang-58 block involves appearing, growth, and disappearing. Furthermore, the turbidite fan changes from channel type to slump fan according to lake level fluctuations.