Soom Shale
| Soom Shale | |
|---|---|
| Stratigraphic range: Hirnantian | |
Typical lithological features of the Soom shale, note the frequent beds of white quartz | |
| Unit of | Cederberg Formation, Table Mountain Group |
| Underlies | Disa Siltstone |
| Overlies | Pakhuis Tillite |
| Thickness | 10–15 m (33–49 ft) |
| Lithology | |
| Primary | Shale |
| Location | |
| Coordinates | 33°00′S 19°00′E / 33.0°S 19.0°E |
| Approximate paleocoordinates | 28°30′S 153°42′E / 28.5°S 153.7°E |
| Region | Western Cape |
| Country | South Africa |
The Soom Shale is a member of the Late Ordovician (Hirnantian) Cederberg Formation (Table Mountain Group) in South Africa, renowned for its remarkable preservation of soft-tissue in fossil material. Deposited in still waters, the unit lacks bioturbation, perhaps indicating anoxic conditions.
It overlies the Pakhuis tillite and is overlain by the Disa Siltstone.
It contains typical Ordovician microfossils, such as chitinozoa, acritarchs and spores, and its shelly fauna is also typical of this time period.
Its macrofauna comprises pelagic organisms that sank rapidly to a barren sea floor. These include brachiopods, eurypterids, conodonts, nektaspids, trilobites, a lobopodian and orthoconic cephalopods.