Yesnaby Sandstone Group
Yesnaby Sandstone Group Stratigraphic range: Givetian (Devonian) | |
---|---|
Type | Group |
Unit of | Old Red Sandstone Supergroup |
Sub-units | , |
Underlies | Caithness Flagstone Group |
Overlies | unconformable on 'basement' |
Lithology | |
Primary | Sandstone |
Other | Siltstone, conglomerate |
Location | |
Region | Orkney |
Country | Scotland |
Extent | West coast of Mainland, Orkney |
Type section | |
Named for | Yesnaby |
The Yesnaby Sandstone Group is a Devonian lithostratigraphic group (a sequence of rock strata) in west Mainland Orkney, Scotland. The name is derived from the locality of Yesnaby where the strata are exposed in coastal cliffs.[1]
Outcrops[]
These strata are only exposed on either side of the Garthna Geo Fault in the Yesnaby area of west Mainland, Orkney.
Lithology and stratigraphy[]
The Group comprises the Qui Ayre Sandstone and the Harra Ebb Sandstone. The basal beds are talus and alluvial fan facies deposited in a fluvial or lake marginal environment probably during the Emsian Stage of the Devonian Period.[2]
References[]
- ^ (BGS on-line lexicon of rock units)
- ^ British Geological Survey 1:100,000 scale geological map (Scotland) Orkney Islands (special sheet)
External links[]
Categories:
- Geological groups of the United Kingdom
- Geologic formations of Scotland
- Devonian System of Europe
- Givetian Stage
- Stacks of Scotland
- Sandstone formations
- Siltstone formations
- Conglomerate formations
- Fluvial deposits
- Lacustrine deposits