Figure F11. Cartoon showing how the bulk magnetic susceptibility of the core half-round samples were used to estimate the amount of magnetite. The front view shows the fractional area that the half core occupies in the susceptibility loop compared to the expected cross-sectional area the loop is designed to measure. The side view schematically depicts the response function of the loop and shows that a ~7 cm length is required to capture 95% of the measured response. Also included is the equation used to calculate the percent magnetite (Mt).