Role of ionizing radiation in the chemical evolution of a substance in nature

Metamorphism is not only characteristic of earth. It also occurs beyond its boundaries, other bodies of the solar system and in interstellar space. Although metamorphism occurs with all rocks, the authors will limit this discussion to a special case: transformation of carbon-containing substances in the earth's crust, in the upper mantle, and in outer space, more precisely, in interstellar grains and meteorites. It should be emphasized that this does not concern all carbon-containing substances, but only organic compounds in the modern sense of this term. The authors will be interested in methane, but will not consider calcium carbonate, although both can be biogenic. Metamorphism of organic matter (OM) increases the concentration of carbon in it. This process is called carbonification, although it only results in the formation of coal in the case of a concentrated bed of OM, and the term open-quotes carbonizationclose quotes seems better for this reason. 24 refs., 10 figs., 1 tab