Structural reverse and its significance to oil and gas accumulation in Ordos block in Neogene

Ordos Block is considered as a rather stable basin in Cenozoic by most researchers. The result of our study is different from this opinion. Before the Cenozoic, tectonic movement directions are uplifted in the eastern part and sunk in the western part of the basin. The oldest Cenozoic strata which deposit in the east part of Ordos Basin are Neogene red clays. They appear on both Pre-Tertiary and Post-Mesozoic geological maps of Ordos Basin. According to fission track dating data from various researchers, structural unconformity contacts, paleo-current directions and regional environment, the western part of Ordos Block have become structural uplift. The red clay strata have not been observed there. The eastern Ordos Block had a wide distribution of red clay which sedimented from west to east on the Lower Cretaceous, Middle Jurassic Anding Formation, Zhiluo Formation, Early-Mid Jurassic Yan'an Formation and Late Triassic Yanchang Formation, respectively. Therefore, we concluded that there existed a structu...