| Matt Formation | |
|---|---|
| Stratigraphic range: Early Oligocene, | |
| Type | Formation |
| Unit of | North Helvetic Flysch |
| Underlies | Blattengrat Nappe, Wildflysch Nappe |
| Overlies | Elm Formation |
| Lithology | |
| Primary | Slate, sandstone |
| Location | |
| Region | Canton Glarus |
| Country | Switzerland |
| Type section | |
| Named for | Matt, Switzerland |
| Named by | Siegenthaler, 1974 |
The Matt Formation is an Early Oligocene-aged marine geological formation that outcrops in the Glarus Alps of the Canton of Glarus, Switzerland.[1][2] It is most notable for its fossiliferous slates found near Engi, known as the Engi slates, Glarner Schiefer (Glarus Slate) or Glarner Fischschiefer ("Glarus fish slate"), which contain the well-preserved fossils of fishes, birds, and sea turtles. The metamorphization of the rock has led to many of the fossils appearing somewhat distorted.[1]