| If either the rate of subsidence or the rate of influx of new sediment increases, the peat will be buried and soon thereafter the coalification process geochemical coalification begins. |
| The most widely accepted explanation is that coalification takes place in response to increasing temperature. |
| The organic carbon content of coal increases gradually with increasing coalification degree. |
| Since microbial activity ceases within a few metres of the Earth's surface, the coalification process must be controlled primarily by changes in physical conditions that take place with depth. |
| Depending on the degree of carbon concentration and coalification, one differentiates between lignite, bituminous coal and anthracite. |
| The effect of increasing pressure due to depth of burial is not considered to cause coalification. |
