Ypresian

In the geologic timescale the Ypresian (pronunciation: /iːˈprɛsiən/) is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between 56 and 47.8 Ma, is preceded by the Thanetian age (part of the Paleocene) and is followed by the Eocene Lutetian age.

The Ypresian is consistent with the lower Eocene.

The Ypresian age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark and the Messel shales in Germany are from this age.

The Ypresian stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after Ypres, the French name of the Belgian (Flemish) city of Ieper (Ieper). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (French: Group d'Ypres), which has an Ypresian age.

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