Comparison of oceanic anomaly block models in the M0-M29 interval from the Japanese, Phoenix, Hawaiian and Keathley lineations indicates that the Hawaiian block model represents the closest approximation to a constant spreading rate record. The new Hawaiian block model differs slightly from that of Larson and Hilde (1975). Currently popular numerical age estimates for polarity chrons, base CM0 (121 Ma), CM16-CM15 (137 Ma) and top CM25 (154 Ma), are consistent with constant spreading rate in the new Hawaiian block model but inconsistent with constant spreading in the Larson and Hilde (1975) block model. A new time scale (CENT94) is based on the above ages and constant spreading in the new Hawaiian block model. Land section magnetostratigraphy, mainly from Italy and Spain, has provided direct correlations of polarity chrons to stage boundaries through ammonite biozones, and indirect correlation through nannofossil and calpionellid biozonations: Barremian-Aptian (base of CM0), Hauterivian-Barremian (upper part of CM4), Valanginian-Hauterivian (base of CM1 In), Berriasian-Valanginian (CM15n), Tithonian-Berriasian (base of CM18), Kimmeridgian-Tithonian (CM22A) and Oxfordian-Kimmeridgian (top CM25). These correlations yield the following stage boundary ages using CENT94: Barremian-Aptian (121 Ma), Hauterivian-Barremian (126 Ma), Valanginian-Hauterivian (131.5 Ma), Berriasian-Valanginian (135.8 Ma), Tithonian-Berriasian (141.6 Ma), Kimmeridgian-Tithonian (150 Ma), and Oxfordian-Kimmeridgian (154 Ma).