Morawan Formation
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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]
| Morawan Formation | |
|---|---|
| Stratigraphic range: Chattian | |
| Type | Formation |
| Unit of | Kawakami Group |
| Sub-units | unnamed, Kamirawan, Lower Hard Shale, Middle Hard Shales, Upper tuffaceous silstone |
| Underlies | Kiroro Formation |
| Overlies | Hombetsuzawa Formation |
| Thickness | 500 m (1,600 ft) |
| Location | |
| Region | Hokkaido |
| Country | Japan |
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: