Llewelyn Volcanic Group
From Wikipedia, the free encyclopedia
TypeGroup
Sub-unitsCapel Curig Volcanic Formation, Foel Fras Volcanic Formation, Conwy Rhyolite Volcanic Formation, Foel Grach Basalt Formation, Braich Tu Du Volcanic Formation
UnderliesCwm Eigiau Formation
OverliesNant Ffrancon Formation
| Llewelyn Volcanic Group | |
|---|---|
| Stratigraphic range: Caradoc Ordovician | |
 Rhyolitic ash-flow tuffs of the Capel Curig Volcanic Formation exposed on the northeastern face of Pen yr Ole Wen, capped by sandstones of the overlying Cwm Eigiau Formation, which can be seen at the top of the face | |
| Type | Group |
| Sub-units | Capel Curig Volcanic Formation, Foel Fras Volcanic Formation, Conwy Rhyolite Volcanic Formation, Foel Grach Basalt Formation, Braich Tu Du Volcanic Formation |
| Underlies | Cwm Eigiau Formation |
| Overlies | Nant Ffrancon Formation |
| Thickness | approx 1400m |
| Lithology | |
| Primary | ash flow tuffs |
| Other | rhyolites, mudstones, siltstones, sandstones, breccias etc |
| Location | |
| Region | northwest Wales |
| Country | Wales |
| Type section | |
| Named for | Carnedd Llewelyn |
The Llewelyn Volcanic Group is an Ordovician lithostratigraphic group (a sequence of rock strata) in Snowdonia, north-west Wales. The name is derived from Carnedd Llewelyn, the highest peak in the Carneddau range where it outcrops.
