Brandywine Blue Gneiss and Barley Mill Gneiss

Brandywine Blue Gneiss and Barley Mill Gneiss. metamorphic. , These boulders started out as igneous rocks formed beneath offshore volcanic islands. They contained the minerals quartz, plagioclase feldspar, and pyroxene. During the Taconic Orogeny they were subjected to extreme temperatures and pressures, metamorphosing them to the gneiss rocks we see today. The Brandywine Blue Gneiss appears darker because it is finer grained, more metaorphosed, and more deformed than the Barley Mill Gneiss., Brandywine Blue Gneiss is a common rock in this area and can be seen in many rock walls, cobblestones, and buildings, and alongside many fields north of Wilmington. When freshly broken, it has a gray-bluish color., Barley Mill Gneiss is abundant along Barley Mill Road. You have most likely seen boulders of it along roadsides in woods, fields, and landscaping., Can you tell the Brandywine Blue Gneiss from the Barley Mill Gneiss? , Hint: Look for the blue color, Do you see the alternating light and dark bands in these rocks? the twists and folds?, Do you know a baseball team named after Brandywine Blue Gneiss? , Wilmington Blue Rocks , The original Wilmington Blue Rocks baseball team was a quarry league team from a "blue rock" quarry.