On the base of analysis and generalization of geological data including indicator features of magmatism riftogenic bedding of Lesser Caucasus oceanic basin are defined in Late Triassic. The newest Paleotectonic setting and development stages of MesoTethys platetectonic structures are suggested in its geodynamic model. On early oceanic stage spreading finished in Bajocian. During period of culmination of the Late Kimmerian tectogenesis of compression of oceanic crust transformations in serpentinite melange and formation of ophiolitic accretion prism of islands on front of active island arc margin of South Caucasian plate and terranean: narrowing of oceanic basins lead to attachment of terranean with formation of twinned oceanic basin and also suture of ophiolitic zone of conjugation of simatic (Garabagh) and sialic (Lok-Agdam) island arcs. In late oceanic stage along with regeneration of spreading and subduction in a new plan and other events and processes groovelike graben-troughs mainly form in each branch of oceanic basin. During period of closure of graben-troughs served as a “trap” in accumulation of autochthonous olistostrome series and allochthonous covers of ophiolites which in residual troughs are covered by non-autochthonous carbonaceous series.