Chalk, chert, and basalt dominate the lithologies of these well-rounded beach cobbles.
Hutton's classic unconformity (Devonian red beds over Silurian graywacke and shale).
Sill that intruded the Liassic shale on the east side of Portrush, Northern Ireland.
At the Caves of Cushendun, an arkosic conglomerate can be found.
Exemplars of the "Passage Creek Fauna" can be seen in this slab collected at the state Fish Cultural Center near Waterlick, Virginia. Brachiopods, crinoids, and bryozoans.
Ordovician carbonates; the obverse of this sample: gigapan.com/gigapans/186325
Contact between sedimentary rock and intrusive igneous dike.
Oldest rock in the North West Highlands
Limestone (calcite) and dolostone (dolomite) layers weather at different rates.
"Grind" means gate - here, during the biggest, storms, waves ramp up and crash through the gate, ripping out huge boulders of ignimbrite and piling them up inland as a crazy storm beach.
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