Abstract:

Zhoukou Depression that crosses the two different tectonic units of North China massif and the southern marginal structural belt of the North China massif is the biggest depression covering an area of 32000km² in the south part of North China Basin. In the Mesozoic, NWW-trend tensile and compressive sags that filled with rapid accumulated volcanic-clastic rocks and oil-bearing molass formations developed in Runan, TanzhuangShengqiu regions due to intracontinental volcanic activities and A-type subduction caused by continent-continent collision of North China Plate and Yangzhi Plate. In the Eogene, an arc-shaped tectonic framework protruding to south as a whole in the depression was controlled by tensile-wrench stress field. It contuins 2 uplifts alternated with 3 sags, including North part sag zone, Linying-Dancheng uplift zone, Central sag zone, PingyuTaihe uplift zone and South part sag zone from north to south. Each of the sag zones ismade up of several dustpan-shaped sags. It formed a group of dustpan-shaped sags with multi-depocenter and multi-hydrocarbon generation center. The tensile-wrench arc-shaped tectonic system resulted from combined acting of dextral shear-wrench movement of Xiayi-Woyang-Macheng fault in Tanlou fault zone with sinistral shear-wrench movement of NWW trend fault in this region. Comprehensive studies indicate that the Central sag zone is favourable for hydrocarbon exploration in the future. The Mesozoic System in the South sag zone and the Lower Paleozoic System in the North sag zone are prospective, and worthy to be further studied.