"Methanic" graphite from lower archean crystalline shists (Kola peninsula)

The isotope composition of carbon in carbon-containing substance from Lower Archean crystalline shists (Kola Peninsula) has been studied. Carbon content in the rocks varies from 0.71 to 1.83 %. It is characterized by the extremely low value d13C — from –45.7 to –31.7 %. The formation of carbon substance apparently occurred during methane oxidation.