Images from Enchanted Rock State Natural Area

Enchanted Rock S.N.A. (S of Llano, TX) is a very special (but too small) state park devoted to Granite. The granite exposed is one of the Town Mountain Granite suite and is of Proterozoic age (1082+-6). There are several large exfoliation domes and castle tors in the park. The largest (Enchanted Rock itself) rises 122 m. above the surrounding landscape. ER is (probably) the second largest exfoliation dome in the U.S., and the largest without dead Confederates carved in the side. ER is well worth a stop to see magmatic foliation, complex K-feldspar megacrysts, spectacular schlieren, rapakivi and anti-rapakivi textures, fantastically weathered granite, large magmatic enclaves, the contact of the batholith, contact metamorphism, post-intrusion cataclastites and exfoliation as it was meant to be seen. This is simply the best place to look at granite in Texas.



Updated and Expanded Information


Description and Chemical Analysis of the Granite at Enchanted Rock
from Barnes and others, 1947



That's the north side of Enchanted Rock itself. Nice exfoliation, eh? Even exfoliation is bigger in Texas
In the foreground is Dr. James "I have a real job at Beloit" Rougvie; the exfoliation sheets in the background are as tall as he is.
Jim is using a specially made device to call a rare Llano granite goat into range so it can be can be captured for study.

Remember Enchanted Rock is a State Park. No Sampling without a Permit.