This paper is based on the data obtained during the field study of active faults carried out in 2005–2006 in the Chita and Amur oblast and South Yakutia in connection with detailed seismic demarcation of the projected East Siberia-Pacific Ocean pipeline route. The comprehensive geomorphic and geophysical fieldwork was focused on paleoseismogeology and accompanied by trenching in the zones of reactivated faults. These works allowed us to specify the available information on the present-day structure, seismotectonic regime, and potential seismic hazard of the conjugation of the Baikal Rift Zone and the arched-block rise of the Stanovoi Ridge.
Active faults play the key role in the formation of the morphological structures and control the seismicity in the Olekma-Stanovoi seismic zone. The detailed geological-structural and morphotectonic studies of fault zones made it possible to estimate the kinematics of the active faults and their activity degree in the Holocene (the last 10 000 years). The latter include old faults such as, for example, the Stanovoi Suture of the Proterozoic age. Most of these faults are the Late Mesozoic and Cenozoic in age. The studies were aimed at reconstructing the past seismogeological processes and were accompanied by trenching across morphological structures that are presumably associated with zones of active tectonic fractures preliminarily studied by geophysical methods. The applied approach allowed us to substantially specify the available information on the seismotectonics and the potential seismic hazard in the region.
Investigations aimed at revealing traces of recent tectonic activity in geological fault zones were carried out in 2006 in the territory of southern Yakutia and the Amur region in connection with works on detailed seismic zoning of the route of the East Siberia-Pacific Ocean oil pipeline. In addition to geological-geomorphological and geophysical studies, the complex investigations included paleoseismogeological studies and were accompanied by the driving of mine workings through topographic forms that could be associated with zones of active tectonic disturbances. This approach made it possible to substantially refine the available information on seismotectonics and the potential seismic hazard of the region.