TECTONIC FRACTURES IN BAIKAL BOTTOM SEDIMENTS (STUDIES OF BDP-98 CORE)

Abstract

Structural studies of BDP-98 core recovered during deep drilling on the Akademichesky Ridge (Baikal Drilling Project) have shown that the Baikal bottom sediments are cut by tension and shear joints of various scales, locally clustered into zones of fracturing. Specific features of the fractures, formed under the conditions of rifting and diagenesis, are related to their latent character, effects of fluid pressure, prevalently normal geometry of extensional jointing, and the structure of the fracturing zones which favors horizontal extension. The obtained results reveal the regularities of active extensional fracturing, as the latter in the case of Baikal is not overprinted with earlier deformation.