The Academichesky Ridge is an underwater segment of the interbasinal uplift
that separates the younger North-Baikal basin, underlain with 42-44 km thi
ck crust, and the older Central-Baikal basin (crust thickness 35 km). Studi
es of the ridge may provide a clue for the structure and evolution of the B
aikal Rift and for the history of paleoclimates. The ridge includes a north
western (uplifted) and a southeastern (subsided) blocks. High-resolution si
ngle-channel continuous seismic profiling of the northwestern block imaged
two major units of its sedimentary cover, a Lower-Middle Miocene (A) and an
Upper Miocene-Pliocene-Quaternary (B) sequences, separated by angular and
azimuthal unconformity.
The paleogeographic scenario of the ridge evolution based on these data sug
gests that till the Middle Miocene it had been a land uplift bounding the C
entral-Baikal basin. Later on, it became destroyed from aside and from abov
e, but isolated isles of land persisted nearly as long as the late Pleistoc
ene.