Home – Home – Jornals – Russian Geology and Geophysics 2005 number 11

Structure of the deposits and basement beneath the South basin of Lake Baikal is investigated down to a depth of 14 km on a profile about 100 km long. Ray tracing modeling of refracted and reflected waves is applied. A discrepancy between the observed and calculated wave traveltimes does not exceed 0.05-0.1 s for the parameters of cross section. In addition, the reliability of the sedimentary cover structure is confirmed by similar synthetic and observed record sections. Four layers with individual characteristics are allocated, divided by seismic boundaries with rather sharp differences of velocity. Velocity changes with depth on the given profile are similar to results of seismic observations in the Selenga depression, in deposits of the West Siberian Plate, Siberian craton and Vilyui basin. It is possible to assume that the sedimentary cover up to 10-12 km thick hosts not only Cenozoic and Mesozoic but also Paleozoic rocks. Therefore it is possible that the age of the South basin of Lake Baikal is more ancient than the Cenozoic-Mesozoic.