Figure 3
Relationship between mean grain size, mean grain sphericity and total porosity, permeability and mean connected pore diameter. Grain sphericity is measured on a scale between 0 and 1 where 1 is entirely spherical, a schematic diagram is shown to represent the range of sphericities according to Krumbein46 plotted in (f). A generally positive relationship with porosity and permeability can be observed in the case of mean grain sphericity in (b) and (d), but no such relationship is present with mean grain size in (a) and (c). A region of outliers is identified by a dashed line in (d) with the same data points also apparent in (b) to a lesser extent. A simple linear fit is calculated between grain sphericity (φs) and porosity (φ), defined by the black line and accompanying equation in (b). It is apparent that there is a generally positive relationship between sphericity and connected pore diameter aside from a small group of four outliers (e).
