Поширення і склад рослинних асоціацій, нагромадження фітомаси, глибина
розкладу органічного матеріалу залежать, головним чином, від палеогеографічних і фаціальних умов. Зміна об’ємів фітомаси в процесах торфо- і вуглеутворення
залежить від низки генетичних та епігенетичних чинників. Найбільше її об’єм зменшується (у 20–40 разів) у седиментогенезі, де переважають біохімічні процеси. Під
час вуглеутворення торф ущільнюється в основному через фізичні фактори і лише
в 1,3–9,4 раза.
The distribution and composition of plant associations, the accumulation of phytomass
and depth of the organic material decay depend on the existing paleogeographical and
facies conditions in the territory of the coal formation.
For the formation of genetic groups of coal with biochemically deep-decayed lignincellulose tissues of collinite and precollinite the conditions of stable and relatively stable
water-encroached forest peat bogs are required. Facies conditions of moving and relatively
moving encroached-flowing forest peat bogs contribute to the coal formation of genetic
type of telinites and posttelinites with weak and relatively weak decay of lignin-cellulose
tissues. In the first case an organic mass acquires homogenous, colloidal or fluidal microstructure, in the second one mainly attrital and fragmentary-attrital.
Change of the phytomass volume in the process of the peat and coal formation depends upon a series of genetic and epigenetic factors. To genetic factors of the phytomass
strinkage belong the processes occurred during the period of sedimentogenesis, in the main
these are biochemical decay of organic plant remains and loss of moisture that have led
to decrease of its volume 20–40 times. In the metamorphic series brown coal-anthracite,
biochemical processes have a considerably weak influence on metamorphosis of the initial
plant substance: in case of the initial stage of coalification only. The main epigenetic
factors influencing the compacting of the peat mass are temperature and pressure, as well
as the primary depth of decay of the organic material (genetic groups) and macrostructure
(homogenous, colloidal, fluidal etc.). On the whole, in the metamorphic series the
compacting factor is 1.3–9.4, that is to say, tens times lower than that one of phytomass in
diagenesis. Maximum compacting factor in the process of metamorphism is observed in
case of well-structure coal mass.