Sill that intruded the Liassic shale on the east side of Portrush, Northern Ireland.
Dolerite sill that intruded the Liassic shale on the east side of Portrush, Northern Ireland.
Close to the contact with the Malmesbury Group (meta-)sediments.
Evidence of Neoproterozoic glaciation overprinted by Appalachian mountain-building.
Other samples from the same site:
Turbidites of the Colonsay Group, after having enjoyed a bit of tectonic sculpting.
Shorelines of an ancient glacier-dammed lake, etched into the sides of this U-shaped valley.
Skolithos tubes define this member of the Cambrian quartzite, north of Loch Assynt.
Proterozoic dike with big feldspars.
Obverse of the sample here:
Is it a "Snowball Earth" tillite? Maybe!
Barberton Greenstone Belt, South Africa
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