A Resource for Information on the Commonwealth's Geology
Aerial view (to the southeast) towards the mouth of the Rappahannock River. Photo by C. M. Bailey
The Rappahannock River forms a broad estuary as it flows to towards the Chesapeake Bay in Virginia’s Coastal Plain province. To the south the Piankatank River is also visible. The Rappahannock and Piankatank rivers are tidal estuaries.
This exposure in a pasture near Cuckoo exposes a poly-deformed hornblende and plagioclase-rich gneiss. Foliation in the gneiss has been refolded. Another interesting feature is the presence of garbenschiefer or “feather amphibolite.” This unusual texture is defined by stellate and featherlike hornblende clusters in the plane of foliation. Three amphibole species occur in this rock […]
When large quantities of magma intrude and solidify in the Earth’s crust they form bodies of intrusive igneous rock known as plutons. The featured image nicely illustrates the edge (geologic contact) of a granitic pluton in the Blue Ridge Mountains of central Virginia. The granite is part of the 706 ± 4 million year old […]