Abstract: The carbonization was studied within schist formation zones at the Baikal ledge southern flank (Western Baikal Area). Isotope carbon composition from schists and carbonaceous material composition with residual hydrocarbon radicals point to their deposition from fluid saturated in hydrocarbons. Dating of muscovite which is syngenetic to carbonaceous material fits with age of 1947±7.8 Ma.
Key words: Siberian Craton, Baikal ledge, carbon, graphite, isotopic composition of carbon, 40Ar-39Ar dating