The Cenozoic Graben in the Marginal Suture Zone of the Siberian Craton: Interior Structural Features and Tectonic Stress Reconstructions

Marginal suture zones of ancient platforms are deep-seated fault zones separating the craton from the mobile belt. Of particular interest is the Pribaikalian marginal suture of the Siberian craton, activated during the Cenozoic rifting. There is one of the youngest structures of the Baikal rift zone – the Buguldeika-Chernorud graben. The graben is formed by the Primorsky and the Tyrgan normal faults, longitudinal relative to the marginal suture. The paper deals with the study of the graben interior structure by the electrical resistivity tomography method and presents the results of tectonic stress reconstruction by different methods. The study has shown that the fault-block structure of the graben and its immediate vicinities formed largely under the northwest to southeast regional extension conditions typical for the Late Cenozoic development of the Baikal rift. Local faults corresponding to other regional dynamic settings make up no more than 26 % of the total amount.