Geology of the National Parks Through Pictures - FDR Memorial

My next post about the Geology of the National Parks Through Pictures is about some parks visited a long time ago within Washington D.C.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.

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Franklin Delano Roosevelt Memorial

The FDR Memorial is built with a reddish-grey granite called Carnelian Granite. The granite was quarried from a quarry near Milbank, South Dakota.

 Carnelian Granite is a course-grained igneous rock that Early Proterozoic in age (about 2 billion years old). The granite is a true granite (unlike many countertops) that contains large minerals of quartz, potassium feldspar, plagioclase feldspar, and biotite.

 This rock was chosen for the memorial because of the similarity in color to the reddish grey field stones that were used at another National Park, the Roosevelt estate at Hyde Park, NY. The rock finish was created to make it look like these stones were "just-quarried" by giving them a rough edge.

References

http://www.dakotagranite.com/

https://www.mindat.org/locentry-1134912.html

https://www.coldspringusa.com/Building-Materials/Project-Portfolio/Franklin-Delano-Roosevelt-Memorial/