Figure 4
Relationship between concretion diameters (R) and widths of reaction fronts (L). The measured data from L1 to L3 and estimated value from L4 to L6 show an almost linear correlation between the width of reaction front ‘L’ and the diameter of the concretion ‘R’ suggesting that concretions were formed under relatively stable sedimentary environments controlled by diffusive solute migration, which is expressed as L = aRb, where a = 0.0807 ± 0.0105 and b = 0.992 ± 0.017.
