QUATERNARY SEDIMENTATION AND SUBSIDENCE HISTORY OF LAKE BAIKAL, SIBERIA, BASED ON SEISMIC STRATIGRAPHY AND CORING

ABSTRACT: The long, continuous, high-latitude, stratigraphic record of Lake Baikal was deposited in three broad sedimentary environ-ments, defined by high-resolution seismic-reflection and coring meth-ods: (1) turbidite depositional systems, by far the most widespread, characterizing most of the margins and floors of the main basins of the lake, (2) large deltas of major drainages, and (3) tectonically or topographically isolated ridges and banks. Holocene sedimentation rates based on radiocarbon ages vary by more than an order of mag-nitude among these environments, from less than about 0.03 mm/yr on ridges and banks to more than about 0.3 mm/yr on basin floors. Ex-trapolating these rates, with a correction for compaction, yields ten-tative estimates of about 25 and 11 Ma for the inception of rifting in the Central and North basins, respectively, and less than 6 Ma for the 200-m sediment depth on Academician Ridge. The Selenga Delta has the distinctive form of a classic progradin