Figure F67. Examples of progressive AF demagnetization of basement archive halves. A. Section 183-1141A-22R-2 at 90 cm from basement Unit 6. The magnetization has a MDF of 30 mT and a single-component magnetization. B. Section 183-1141A-24R-2 at 77.5 cm from basement Unit 6. The magnetization has a MDF of 8 mT and a two-component magnetization. J₀ is the magnetization intensity before AF treatment.