Diagenetic Self-Organization and Stochastic Resonance in a Model of Limestone-Marl Sequences

Figure 2

Schematic representation of Munnecke et al. [27] and Böhm et al.’s [28] conceptual model for the generation of self-organized rhythmites. Left diagram: as fresh sediment is buried, aragonite dissolution occurs in a bacterially active ADZ. Carbonate and calcium ions are transported by diffusion and advection and the sediment immediately above the ADZ is cemented by calcite (dominantly) and aragonite precipitation. Center diagram: as the sediment is buried, the cemented zone passes the ADZ with much-reduced aragonite dissolution rates. Right diagram: as the cemented zone gets buried below the ADZ, fresh sediment is made available again to strong aragonite dissolution, and the cycle repeats itself again. The result is a sequence of cemented sediments (limestone-rich) alternating with carbonate-depleted sections (marl).