The Puget Group is a geologic group in Washington (state). It preserves fossils dating back to the Paleogene period.
In the northern area of group around Renton, Washington, the Group has been divided into three formations (from oldest to youngest), the Tiger Mountain Formation, the Tukwila Formation, and Renton Formation.
Age
The total deposition time has been estimated to be as short as approximately 7.7 million years, from around based on isotopic data reported in 1993 or as long as based on the paleofloristic data of Wolfe (1968, 1977)
Western North American floral stages
The Western North American floras of the Eocene were divided into four floral "stages" by Jack Wolfe (1968) based on work with the Puget Group plant fossils. The four stages,
Franklinian,
Fultonian,
Ravenian, and
Kummerian covered the Early Eocene through early Oligocene, and three of the four were given informal early/late substages. Wolfe tentatively deemed the Franklinian as Early Eocene, the Fultonian as Middle Eocene, the Ravenian as Late, and the Kummerian as Early Oligocene.
The beginning of the Kummerian was refined by Gregory Retallack
et al (2004) as 40 mya, with a refined end at the Eocene-Oligocene boundary where the younger
Angoonian floral stage starts.
See also
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List of fossiliferous stratigraphic units in Washington (state)
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Paleontology in Washington (state)
