Kopp, Raub, Kirschvink, et al. examine a PETM magnetofossil spike

Robert E. Kopp, Timothy D. Raub, Dirk Schumann, Hojatollah Vali,
Alexei V. Smirnov, and Joseph L. Kirschvink (2007) Magnetofossil Spike During the Paleocene-Eocene Thermal Maximum: Ferromagnetic Resonance, Rock Magnetic, and Electron Microscopy Evidence from Ancora, New Jersey, USA. Paleoceanography, 22(4):PA4103, 16 November 2007. CaltechAUTHORS