http://www.sciencedirect.com/science/article/pii/S1674987111000594

A new model is suggested for the history of the Baikal Rift, in deviation from the classic twostageevolution scenario, based on a synthesis of the available data from the Baikal Basin and revised correlationbetween tectonicelithologicalestratigraphic complexes (TLSC) in sedimentary sections around LakeBaikal and seismic stratigraphic sequences (SSS) in the lake sediments. Unlike the previous models, therevised model places the onset of rifting during Late Cretaceous and comprises three major stages whichare subdivided into several substages. The stages and the substages are separated by events of tectonic activityand stress reversal when additional compression produced folds and shear structures. The events thatmark thestage boundaries show up as gaps, unconformities, and deformation features in the deposition patterns.The earliest Late CretaceouseOligocene stage began long before the IndiaeEurasia collision in a setting ofdiffuse extension that acted over a large territory of Asia. The NWeSE far-field pure extension produced anNE-striking half-graben oriented along an old zone of weakness at the edge of the Siberian craton. That wasalready the onset of rift evolution recorded in weathered lacustrine deposits on the Baikal shore and ina wedge-shaped acoustically transparent seismic unit in the lake sediments. The second stage spanning LateOligoceneeEarly Pliocene time began with a stress change when the effect from the Eocene IndiaeEurasiacollision had reached the region and became a major control of its geodynamics. The EWand NE transpressionand shear from the collisional front transformed the Late Cretaceous half-graben into a U-shaped onewhich accumulated a deformed layered sequence of sediments. Rifting at the latest stage was driven by extension from a local source associated with hot mantle material rising to the base of the rifted crust. Theasthenospheric upwarp first induced the growth of theBaikal dome and the related change fromfiner to coarsermolasse deposition. With time, the upwarp became a more powerful stress source than the collision, and thestress vector returned to the previous NWeSE extension that changed the rift geometry back to a half-graben.The layered Late PlioceneeQuaternary subaerial tectonicelithologicalestratigraphic and the Quaternarysubmarine seismic stratigraphic units filling the latest half-graben remained almost undeformed. The riftingmechanisms were thus passive during two earlier stages and active during the third stage.The three-stage model of the rift history does not rule out the previous division into two major stages butrather extends its limits back into time as far as the Maastrichtian. Our model is consistent with geological,stratigraphic, structural, and geophysical data and provides further insights into the understanding of riftingin the Baikal region in particular and continental rifting in general.