Based on the data of drilling cores, thin sections, field outcrops and seismic interpretation, the sedimentary
facies and seismic facies of the Majiagou Member 5 in the central-eastern Ordos Basin are analyzed, and the structuralsedimentary response characteristics are discussed. The research shows that restricted and evaporation platform facies are
developed in the subsalt strata of the Majiagou Member 5 in the study area, which can be further divided into several
sedimentary microfacies types,such as granular shoal, dolomite flat, limestone flat, gypsum-salt lake and so on. The
seismic facies interpretation model of main microfacies was established by using well-seismic combination method.
Based on this, the seismic facies and sedimentary facies interpretation of seismic sections in the whole area is carried out,
and lithofacies-paleogeographic maps are revised. It is considered that the main part of the study area in this period
presents a sedimentary pattern of“uplift and depression alternating”and“multi-uplifts and multi-depression”. The
sedimentary model of the subsalt strata of the Majiagou Member 5 in the Ordos Basin is established. |