Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 145.

To mark the 70th birthday of Neil D. Opdyke, a Chapman Conference entitled "Timescales ofthe Internal Geomagnetic Field" was held at the University of Florida in Gainesville on March 9-11, 2003. This AGU Chapman Conference was sponsored by the U.S. National Science Foundation, University of Florida, Florida Museum of Natural History, and 2G Enterprises. Forty-one talks and twenty-three posters were presented during the three-day meeting. This monograph contains twenty-four of those papers, and is a balanced subset ofthe papers presented at the conference. The monograph is divided into three parts. Part 1 deals with the geocentric axial dipole (GAD) hypothesis, continental reconstruction, and long-term geomagnetic field behavior. Part 2 comprises papers on magnetic polarity stratigraphy and the acquisition of sedimentary magnetization. Part 3 deals with secular variation, paleointensity, and short-term geomagnetic field behavior. These are all topics that have been substantially impacted by Neil's scientific work.