The array of Leg 171B sites yielded a detailed magnetostratigraphy of the Aptian/Albian boundary interval (including polarity Subchron M''-2r'') and the Cenomanian through Eocene. All polarity chrons from C31r (early Maastrichtian) through C15r (latest Eocene) are present as relatively thick polarity zones at one or more sites. The precise placement of polarity reversals within individual Milankovitch orbital-sediment cycles should be possible with further focused sampling. The current array provides a reference suite for enhanced biostratigraphic calibration and general astronomical tuning of the Maastrichtian through Eocene magnetic polarity time scale and oceanic spreading rates.