Adjust layer parameters to explore how the apparent resistivity curve changes.
Thickness is considered infinite.
ρ₁ > ρ₂ < ρ₃
Conductive middle layer (e.g. saturated sand between dry soils). Curve dips then rises.
ρ₁ < ρ₂ > ρ₃
Resistive middle layer (e.g. dry gravel between clay). Curve rises then falls.
ρ₁ < ρ₂ < ρ₃
Monotonically increasing (e.g. clay → sand → bedrock). Curve rises continuously.
ρ₁ > ρ₂ > ρ₃
Monotonically decreasing (e.g. gravel → sand → saline water). Curve falls continuously.
The plotted curve represents Apparent Resistivity (ρa) over electrode spacing, which is essentially what a Pseudosection plots spatially.
The pseudosection/plot is NOT a true depth section. It is a distorted, volumetrically averaged image of the subsurface. Mathematical Inversion is required to recover the true resistivities (ρ₁, ρ₂, ρ₃) and thicknesses that you are manipulating in the controls above.