THE POWER AND REACTIVE CONTINUUM MODELS AS PARTICULAR CASES OF THE Q-THEORY OF ORGANIC-MATTER DYNAMICS

The reactive continuum model (Boudreau and Ruddick, 1991), the power m odel (Janssen, 1984; Middelburg, 1989), and the a-theory (Bosatta and Agren, 1991a) have been used to describe decomposition of organic matt er; the reactive continuum model has also been used to model the kinet ics of kerogen cracking, i.e., of oil and gas generation (Burnham et a l., 1987). The reactive continuum model describes the organic matter a s being composed of a continuous distribution of reactive types; the b asic premise in the power model is that the reactivity of organic matt er decreases with time. The q-theory is based on the idea that organic matter is composed of an infinite spectrum of interacting (through mi crobial and physicochemical processes) reactive types. We show here th at the reactive continuum model and the power model can be deduced as particular cases of the q-theory. The q-theory reduces to the reactive continuum model if all interactions between the components of the spe ctrum are neglected, whereas the power model is obtained under specifi c assumptions about microbial properties. The q-theory is, therefore, not only mathematically more general but has also a larger explanatory power.