Abstract:

Based on the systemic coring data and  analysis test data, combined with well logging and seismic data, and according to the characteristics of lava lithology, electrical property,petrochemistry and so on, along with the seismic reverberation of different lithology and lithofacies, volcanic strata of Kalagang Formation in Niu dong area in Malang sag of Santanghu basin can be divided into different units，such as layer, cyclothem, period, and sub-gyration. Regarding volcanic eruptible period as the basal unit of lava stratigraphic division and correlation, the lava stratigraphic division and correlation in this area has been done. The study indicates that fracture eruption is the main eruptible mode in Kalagang Formation. Volcanic distribution reveals that the thickness and number of the volcanic layer decrease distinctly from southwest to northeast. Kalagang Formation has  the thickness of more than 1,000 meters and can be divided into eight sub-volcanic eruptible periods and four sub-gyrations.

Key words: lava stratum, division, volcanic eruptible period, sub-gyration, Santanghu basin