A SEISMIC-GEOLOGICAL MODEL OF THE UPPER PART OF THE RIPHEAN INTERVAL AT THE SOUTHERN SLOPE OF THE BAIKIT ANTECLISE

E. G. Keller, G. D. Ukhlova, A. A. Gusenitsa, A. I. Keller, V. N. Bespechny

The Riphean deposits have been proved to be distributed throughout the study area. The reflecting horizon R0 was traced in seismic sections, marking the Riphean erosion surface, as well as the reflecting horizons R1, R2, R3, and R4, which in seismostratigraphic correlation correspond to bases of the Iremeken, Tokur, Kopchera, and Yurubchen (Shikta) formations. In the southeastern part of the area the reflecting horizons R1, R2, R3, and R4 were found to be dipping into the deep graben-rift, where there is a group of the Riphean reflecting horizons above them – R1/1 and R1/2. They were tied to bases of the Upper Riphean Lower Angara and Dashkino formations. The authors examined seismogeological features of the Riphean complex and made a seismostratigraphic analysis of the upper part of the Riphean deposits. Two types of seismic facies were revealed in the seismic wavefield in the interval corresponding to the Riphean deposits. The authors mapped a promising type of seismic facies tied to massive carbonaceous rocks. The zones of increased rock fracturing were revealed in the focusing transformation sections. The most promising Riphean zones are expected in the crossing areas of mainly massive deposits and zones of predicted increased fracturing.

Key words: Riphean deposits, Baikit anteclise, reflecting horizon, seismic facies.