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.
Selected locations showing truncated cross bed sets are labeled.
Proterozoic dike with big feldspars.
Obverse of the sample here:
Is it a "Snowball Earth" tillite? Maybe!
An example courtesy of Allen Fraser, local geology expert.
Barberton Greenstone Belt, South Africa
Sample courtesy of Ken Rasmussen and his colleague, the Baltimore-based archaeologist Henry Ward.
Oldest fossils in the United Kingdom.
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