巴尔顿期（也被称为奥弗斯期）是中始新亚世的一个阶段，起始和终止时间分别为40.4 ± 0.2百万年前和37.2 ± 0.2百万年前。

• GeoWhen Database - Bartonian

Not to be confused with the Bortonian of the New Zealand geologic time scale.

The Bartonian is, in the ICS's geologic time scale, a stage or age in the middle Eocene epoch or series. The Bartonian age spans the time between 41.2 and 37.8 Ma. It is preceded by the Lutetian and is followed by the Priabonian age.