Figure 2.
The plot presents diffusion coefficient in square metres per second against pre test permeability in square metres, boom clay values range from about 2.5 multiplied by 10 to the power minus 10 to 4.7 multiplied by 10 to the power minus 10 as permeability increases from about 1 multiplied by 10 to the power minus 19 to 1 multiplied by 10 to the power minus 18, with a logarithmic fit y is 8 multiplied by 10 to the power minus 11 ln of x plus 4 multiplied by 10 to the power minus 9 and R 2 of 0.8076, synthetic samples increase from about 1.1 multiplied by 10 to the power minus 10 to 6.5 multiplied by 10 to the power minus 10 as permeability rises from about 1 multiplied by 10 to the power minus 19 to 1 multiplied by 10 to the power minus 16, with a logarithmic fit y is 9 multiplied by 10 to the power minus 11 ln of x plus 4 multiplied by 10 to the power minus 9 and R 2 of 0.9933, showing an increasing trend for both datasets.Cross-plot of diffusion coefficient against pre-test intrinsic permeability for Boom Clay samples compacted to a pressure equivalent to 400 m depth of burial and synthetic samples comprise of different mineralogical compositions. The graph suggests a fundamental relationship exists between these two coefficients, with the offset between natural and synthetic samples potentially linked to the compaction pressure of the synthetic sample (from Harrington et al., 2025)