Seasonal patterns of carbonate diagenesis in nearshore terrigenous muds: Relation to spring phytoplankton bloom and temperature

摘要

Pore water saturation state with respect to calcite and aragonite minerals in Long Island Sound sediments fluctuates from saturated and near saturated conditions during late fall, to undersaturated during winter, before slowly changing to supersaturated conditions during late spring. Undersatura- tion occurs during cold, winter periods when lower rates of ΣCO_2 production (low rates of heterotrophic metabolism) and oxidation of reduced minerals such as FeS lower calcium carbonate saturation states. Direct evidence that dissolution of both calcites and aragonite are occurring during this season comes from the simultaneous increases in excess pore water carbonate dissolution products Ca~2+, F~- and Sr~2+ during periods of pore water undersaturation.