Figure 2
From: Seep-carbonate lamination controlled by cyclic particle flux
Laminae counting and elemental composition analysed with LA-ICP-MS.
(a) Scan of epoxy impregnated, polished slab, highlighting individual 204 laminae and spots of isotope samples (1–10; see Supplementary Table S1); note mottled intervals (black arrows) sometimes lack distinct lamination; white arrow indicate overlapping of lamina #101; epoxy resin and unfilled porosity appear dark grey to black. (b) Thin-section scan of the build-up top displaying the relative position of the thin section used for LA-ICP-MS (inlet) and the actual ablation spots (black rectangle in the upper right of the blown-up section). (c) Thin section micrograph (plane-polarized light) displaying the LA-ICP-MS ablation craters within clotted and fibrous aragonite (Cfa) and fossilised biofilms (see also Supplementary Fig. S1); craters that yielded high aluminium (Al) contents are associated with biofilms (purple circles); arrow points towards the top. (d,e) bar diagrams showing element contents of LA-ICP-MS analyses; high strontium (Sr) contents agree with aragonite as dominant carbonate cement; spots with relative high contents of terrigenous aluminium (Al) are highlighted (grey bands); note that high silicon (Si) and magnesium (Mg) contents correlate with high Al contents.
