Germany Valley, West Virginia. Ordovician carbonates with fossils.
An outcrop north of Loch Assynt showing the basal Pipe Rock (Cambrian quartz arenite).
Mahantango Formation, Trinity Church site, Fort Valley, Virginia.
Ancient glacier-dammed lake shores, etched into the hillside of this U-shaped valley.
Hutton's classic unconformity (Devonian red beds over Silurian graywacke and shale).
Plagioclase-rich anorthosite in a cobble. Shows a fair amount of weathering as well as nice reaction rims.
This is the obverse of this sample:
Flatlying strata from a Permian lake, exposed in coastal western "Mainland" Orkney
Basalt flow with "warbonnet" columnar jointing, pillow lavas.
Is it a "Snowball Earth" tillite? Maybe!
Stratotype for the Ordovician-Silurian boundary. Figured out by Charles Lapworth, using graptolites.
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