Geochemical Kinetics and Transport

The kinetics of geochemical and biogeochemical processes can be studied in isolation in the laboratory, but only rarely is it possible to separate these processes from those of transport when considering their importance in natural systems at the field scale. This is because the driving force for most reactions of interest in water—rock interaction is transport. The most intense geochemical and biogeochemical activity occurs at the interface between global compartments like the oceans, the atmosphere, and the Earth’s crust where elemental and nutrient fluxes provide the maximum driving force for reactions to take place. The important role of transport in these settings makes it critical to consider these time-dependent processes in conjunction with those processes we think of as more purely biogeochemical. In other words, these global interfaces are

open systems

, where both mass and energy transfers must be accounted for.