Mahantango Formation, Trinity Church site, Fort Valley, Virginia.
Pliocene scallop from the Yorktown Formation.
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:
Unusual rock for Iceland: felsite (granite, more or less).
Flatlying strata from a Permian lake, exposed in coastal western "Mainland" Orkney
Another view of this sample: gigapan.com/gigapans/191903
Basalt flow with "warbonnet" columnar jointing, pillow lavas.
Is it a "Snowball Earth" tillite? Maybe!
Not a member yet? Sign up