Depositional and paleohydrogeological controls on the distribution of organic matter and other reactive reductants in aquifer sediments

Aerobic degradation during sediment deposition appears to control the molecular composition and reactivity of SOM in aquifer sediments and to affect the potential of subsequent diagenetic pyrite formation. In addition, (paleo)hydrological conditions may result in the accumulation of a ferrous iron-bearing carbonate phase precipitated during the exfiltration of Fe(II)-containing anoxic groundwater.