Carbonization of Carbonates and Fractionation of Stable Carbon Isotopes in a Dynamic Slip ZoneстатьяПеревод
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 11 ноября 2020 г.
Аннотация:Data obtained on carbonates and metaterrigenous rocks of the Devonian complex of the SultanUizdag Range, northwestern Uzbekistan, which are carbonized in local deformation zones, are used in a generalized interpretation of the genesis of carbonaceous matter by means of decomposition of carbonates under the effect of seismogenic movements. The release of free carbon is facilitated by synchronous Fe–Mg metasomatism and by the reducing conditions in the presence of hydrogen. Based on literature data on experimental modeling of carbonization processes at high-speed shear deformations of carbonates in a hydrogen medium, a possible scenario is considered for the generation of hydrogen on the surfaces of quartz dislocations in the presence of water in metaterrigenous rocks in association with carbonates. The variation of carbon isotope composition over the volume of the carbonate and terrigenous rocks is extremely heterogeneous, with the 13C isotope enriched in the fracture zones and 12C enriched in the near-fracture volumes of decompression-damaged rocks. It is hypothesized that deformations can affect the fractionation of stable carbon isotopes. With regard for literature data, it is demonstrated that isotope exchange can proceed between the free carbon and carbonate carbon. Various aspects are discussed of the influence of mineral-phase and structural–textural transformations of carbonate rocks at their thermomechanical decomposition under shearing on the geomechanical behavior of the fracture, manifestations of mechanical instability in it, and causes of frictional weakening.