Sequence stratigraphic controls on formation of dolomite: Insights from the Carboniferous Um Bogma Formation, Sinai-Egypt

In this paper we demonstrated that integrating sequence stratigraphy to dolomite formation is a probable approach for understanding the condition of dolomite formation at sediment surface or near subsurface. The employment of this technique is possible, because parameters controlling the sequence stratigraphic framework could have a profound impact on processes of dolomite cementation and dolomitization during early diagenesis. The Early Carboniferous dolostone beds in southwestern Sinai, Egypt, are interpreted to have been formed by dolomitization during transgressive system tract and early highstand system tract. The appropriate conditions for formation of extensive dolomite including, the seawater with modification by microbacteria or meteoric water dilution in the anoxic environment, exist of required ions (Ca²⁺, CO3^2-, Mg²⁺), nucleation sites and effective fluxes of dolomitizing fluid through the shelf were be provided during the Middle Viséan marine transgression in the Um Bogma area. By this mean, the dolomitization began early and penecontemporaneous with carbonate deposition at sediment surface or near subsurface and continued by precipitation of dolomite overgrowths and pore filling dolomite cements during later diagenesis, which is supported by oxygen isotope analyses.