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 micrograph illustrates a mylonite from the Hylas Zone in the eastern Piedmont ~5 km west of Doswell, Virginia. The rock is characterized by a well-developed foliation with elongate quartz ribbons (transparent grains) and feldspar porphyroclasts. The rock originally was a granodiorite that was strongly deformed and sheared, under ductile conditions, into a mylonite. Checkout […]
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 […]