Figure F26. Ratios of magnetization removed from split cores after 10 mT alternating-field (AF) demagnetization along the x-, y-, and z-axes of the core. The core orientation system is shown in the lower right corner along with the a schematic of the vertical and radial overprint. As discussed in the text, much more magnetization is removed along the z-axis than along the x- or y-axes, which is a result of removal of a large vertical drill-string overprint. The ratio of z:y removed is much larger than z:x removed, particularly for APC cores, which indicates the presence of a radial overprint. APC = advanced hydraulic piston corer; XCB = extended core barrel; and RCB = rotary core barrel.