Port Deposit Gneiss | |
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Stratigraphic range: Paleozoic | |
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Polished slab of the Port Deposit Gneiss, about 10.7 cm wide
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Type | metamorphic |
Lithology | |
Primary | gneiss |
Location | |
Region | PiedmontofMaryland |
Extent | eastern Maryland |
Type section | |
Named for | Port Deposit, Maryland |
The Port Deposit Gneiss is a Paleozoic gneiss formation in Cecil County, Maryland. It is described as a "Moderately to strongly deformed intrusive complex, chiefly composed of quartz diorite gneiss. Rock types include gneissic biotite-quartz diorite, hornblende-biotite-quartz diorite, and biotite granodiorite, with minor amounts of quartz monzonite and hornblende-quartz diorite. Moderate protoclastic foliation grades into strong cataclastic shearing."[1]Itintrudes into the Volcanic Complex of Cecil County.
The Port Deposit Gneiss has been quarried along the east as well as the west bank of the Susquehanna River for over 100 years.
Port Deposit Gneiss was used in:[2]