Morawan Formation
The Morawan Formation is a Chattian age siliceous marine geological formation of the Oligo-Miocene Japanese Kawakami Group of eastern Hokkaido prefecture. The formation is fossil rich and contains source units where toothed baleen whales and Desmostylians have been discovered.
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.
Fossil species from the Morawan Formation include:
- Ashorocetus eguchii
- Morawanocetus yabukii
- Aetiocetus tomitai
- A. polydentatus
