Integrated Study of Tectonics-Sequence Stratrigraphy-Sedimentology in the Qikou Sag and Its Applications

This paper discusses the Cenozoic tectonic evolution,sequence framework,and sedimentary systems of the Qikou sag based on massive geological,geochemical,and geophysical data.The Cenozoic tectonic evolution of the Qikou sag can be divided into two stages and four tectonic episodes.The Paleogene and Neogene strata in the Qikou sag can be divided into 4 secondary-order sequences and 17 third-order sequences.Several slope break types are recognized,these include the faulted abrupt slope zone,multi-stage fault-terrace zone,fault-terrace abrupt slope zone,and flexure slope break zone,and their corresponding sequence developing modes and vertical evolution modes are suggested.Finally,four main provenance systems(northern Yanshan provenance,western Cangxian provenance,southern Chengning provenance,and eastern Shaleitian provenance) as well as their sedimentary systems are proposed.