EVIDENCE OF MICROBIAL-INDUCED MINERALIZATION IN THE ROCKS OF THE TOMTOR CARBONATITE COMPLEX (ARCTIC SIBERIA)
Carbonates of the Tomtor complex of ultrabasic alkaline rocks and carbonatites (north of the Republic of Sakha-Yakutia) are distinguished by a wide range of carbon isotopic composition δ<sup>13</sup>C from +2 to –59.9‰. The paper gives a description of the geological position, localization patterns, mineral and chemical composition, relationship with REE mineralization of samples with δ<sup>13</sup>C carbonates from –25 to –59‰. The formation of abnormally low δ<sup>13</sup>C in carbonates is due to the biogenic oxidation of methane from δ<sup>13</sup>C<sub>met</sub> to –70‰.