A.I.duPont Students see geology of the Delaware Piedmont
This page tagged with:
- amphibolites
- Appalachian Piedmont
- Baltimore Gneiss
- Barley Mill Gneiss
- bedrock
- Brandywine Blue Gneiss
- Brandywine Springs
- Clinopyroxene
- Cockeysville Marble
- crystalline rocks
- deformation
- Delaware
- Enstatite (Bronzite)
- fall zone
- Fall Zone
- Faulkland Gneiss
- Garnet
- geology
- Glenarm Series
- Greenbank
- Hornblende
- Hypersthene
- igneous
- magma
- Magnetite
- mapping
- Metapyroxenite and metagabbro (undifferentiated)
- Mica
- Microcline
- Mount Cuba
- Orthoclase
- Orthopyroxene
- pegmatite
- Plagioclase
- Pyroxene
- Quartz
- Red Clay Creek
- Rockford Park Gneiss
- rocks
- Serpentinite
- Setters Formation
- Sillimanite
- Taconic Orogeny
- tectonics
- topography
- Wilmington Complex
- Wissahickon Formation
- Wooddale
- Yorklyn
- Zircon
Biotite Tonalite
Sbt
Fine- to medium-grained, equigranular biotite tonalite usually occurring as rounded boulders. Tonalites are leucocratic (15 to 25% modal mafic minerals), light gray to buff on fresh surfaces, and locally contain mafic enclaves with reddish rims, the result of iron hydroxide staining. Possibly intrusive into the Perkins Run Gabbronorite Suite.



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