1. Origin and Transformations of Organic Matter in Geosphere

To speak about the organic matter in the geosphere means, in fact, to speak about the organic matter in the Earth’s crust. This, together with the so-called upper mantle, builds up the lithosphere (Fig. 1.1). It has been estimated that the amount of organic carbon in the biosphere, which has accumulated so far and further transformed in the geosphere, is around 6.4 × 10¹⁸ kg. The average annual accumulation of organic carbon in the geosphere since the beginning of life on Earth to date has been estimated to 3.2 × 10⁸ kg, which accounts for only about 0.01 % compared to the average annual organic carbon production only in marine environment. Nevertheless, as the organic matter in the geosphere has been accumulating since the appearance of photosynthesis, and then continued during a long geological time (about 2 billion years), its total amount in the geosphere is now about 2000 times larger than the amount of organic matter in the biosphere.