Wester Ross Supergroup | |
---|---|
Stratigraphic range: 1000–960 Ma | |
![]() Torridon Group sandstones near Diabaig | |
Type | Geological supergroup |
Sub-units | Sleat Group, Torridon Group, Morar Group, Iona Group, Tarskavaig Group |
Underlies | Ardvreck Group or Loch Ness Supergroup (tectonic contact) |
Overlies | Lewisian complex or Stoer Group |
Area | Northwestern Scotland |
Thickness | 6–9 km |
Lithology | |
Primary | Sandstone (psammite where metamorphosed) |
Other | Conglomerate, mudstone (pelite where metamorphosed) |
Type section | |
Named for | Wester Ross |
The Wester Ross Supergroup is one of the subdivisions of the Neoproterozoic sequence of sedimentary rocks (or their metamorphic equivalents) in the Scottish Highlands. It lies unconformably on medium to high-grade metamorphic rocks and associated igneous rocks of the Archaean and Paleoproterozoic age Lewisian complex or locally over the Mesoproterozoic sedimentary rocks of the Stoer Group.[1] The contact between the Wester Ross Supergroup and the next youngest of the Neoproterozoic sequences in the Scottish Highlands, the Loch Ness Supergroup, is everywhere a tectonic one.[2]