关键词: 陆相, 湖泊沉积层, 序地层学, 冀中坳陷

Abstract: The concept and method of sequence stratigraphy were applied to the reinterpretation of Palaeogene formation in the Jizhong depression.Having interpreted the seismic and drilling data,Palaeogene formation is divided into four sequences.Each sequence can be subdivided into three depositional system tracts:lowstand,transgression and highstand system tracts.The deposition of system tract or the distribution of lithofacies was controlled by both the water level (high or low)and the tectonic subsidence,so that each sequence consists of transgressive regressive sedimentary cycle. Having analysed the existing data,we know that the transgression system tract in Jizhong depression may be relating to "sea overflow" or "transgression",consists of thick dark mud shale layers with carbonate interbeds(including bioclastic limestone) and a great deal of microfossils relevant to a salt water environment.The microfossils were the main matter that became oil and gas.The favourable reservoirs are bottom fan,slope fan,slope channel sand body and transgressive delta in the lowstand tract beneath the transgression system tract,regressive delta and the fan delta sand body in highstand tract above transgression system tract.The trap type obviously depends on the generation type of sand body.

Key words: continental fades, lake deposit, sequence stratigraphy, Jizhong depression