CoachA Zijderveld diagram plots the end points of the remaining remanence vector after each step of demagnetisation on two planes at once, the horizontal (north against east) and a vertical one (north against down), with a common north axis. A component removed alone over a range of steps plots as a straight segment; a segment ending at the origin is the characteristic remanent magnetisation (ChRM), the most stable component, interpreted as the primary one when tests allow.
