Fig. 2: Occurrences of sulfide rosettes and their paragenetic context. | Communications Earth & Environment

Fig. 2: Occurrences of sulfide rosettes and their paragenetic context.

From: Evidence for high-frequency oxygenation of Ediacaran shelf seafloor during early evolution of complex life

Fig. 2

a Bedding-parallel distribution of sulfides (opaque) in a granular phosphorite. b Close-up of the area marked in (a) showing local abundance of sulfide rosettes. c–e A phosphatic dolostone composed of dolomite matrix (Dol-1), phosphate (Ap) peloids and abundant sulfide rosettes. d Overlayered elemental distribution of Mg, S, and P for the area marked in c. e Close-up of the area outlined in c, showing that sedimentary lamina (arrows) drape around opaque sulfide rosettes (SR) and partial dissolution of phosphate peloid grains (Ap) and dolomite (arrowheads). f A sulfide rosette crosscutting phosphate grains and dolomite matrix (arrowheads). g, h Dissolution of phosphate grains, dolomite and glauconite (Gl) and replacement by sulfide rosettes. Note the presence of quartz (Qtz) in the rosettes. i A second generation, highly birefringent dolomite (Dol-2) cementing and replacing isotropic phosphatic granules (Ap). a Thin section scan; b, c, e–g transmitted plane-polarized light image; d elemental map by EDS; h secondary electron image; i, transmitted light image, crossed polars.

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