Type Group Region Orkney Named for Yesnaby | Country Scotland Primary Sandstone Underlies Caithness Flagstone Group | |
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Unit of Old Red Sandstone Supergroup Sub-units Qui Ayre Sandstone Formation, Harra Ebb Sandstone Formation Overlies unconformable on 'basement' Other siltstone, conglomerate | ||
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.
Contents
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 Formation and the Harra Ebb Sandstone Formation. 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.
References
Yesnaby Sandstone Group Wikipedia(Text) CC BY-SA