Global correlation using magnetic susceptibility data from Lower Devonian rocks

Magnetic susceptibility data from marine rocks can be used for global correlation because of synchronous variations in global erosion. We show here correlations between magnetic susceptibility data from two Lower Devonian, biostratigraphically well defined sections, one in northwestern Spain, and one from the Anti-Atlas region of Morocco. Using the Moroccan outcrop section, we correlate to cuttings from a Bolivian well with minimal biostratigraphic control. Using the magnetic susceptibility data, we identify the Lower Devonian, Pragian-Emsian, and lower-upper Emsian stage boundaries in the Bolivian well samples.