Morawan Formation

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Morawan Formation
Stratigraphic range: Chattian
TypeFormation
Unit ofKawakami Group
Sub-unitsunnamed, Kamirawan, Lower Hard Shale, Middle Hard Shales, Upper tuffaceous silstone
UnderliesKiroro Formation
OverliesHombetsuzawa Formation
Thickness500 m (1,600 ft)
Location
RegionHokkaido
CountryJapan

The Morawan Formation is a Chattian age siliceous marine geological formation of the Oligo-Miocene Japanese Kawakami Group of eastern Hokkaido prefecture.[1][2][3] The formation is fossil rich and contains source units where toothed baleen whales (Aetiocetidae) and Desmostylians have been discovered.[4]

The Morawan Formation is a very siliceous unit containing hard platy shales interbedded with tuffaceous mudstones and sandstones, and some pumice. The unnamed lower member is a hard platy shale alternating with beds of tuffaceous mudstones and sandstones, the Kamirawan member is a tuffaceous sandstone with pumice, the Lower Hard Shale is a very siliceous hard shale with tuffaceous sandstones and mudstones, and the Middle Hard Shales and the Upper tuffaceous siltstone are similar.[5]

Fossil species from the Morawan Formation include:

References

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