acteristic that looks like a doughnut ring with a gnamma pit in the center. Along the decent we come across a Tent Blister, a sheet of rock that breaks in the middle and the center portion of the rock elevates into a point. As we continue down, we come across the best place to see exfoliation in progress. Exfoliation consists of sheets of rock that break from the surface and slide (very slowly) down hill.Schlieren, thin layers of dark minerals found within a granite, can be seen from this side of enchanted rock. Geologists have conflicting theories on how these are formed. Geologists do agree on a process that they use to date rock formations called Isotopic age dating. This is a formula that allows them to solve for age using known variables from the rock. Enchanted Rock has been dated from the Proterozoic age (1082+-6).You can see the Contact Zone by traveling up Sandy Creek from the eastern parking lot. This zone has pieces of broken off metamorphic rock and pegmatites (igneous intrusion with very large crystals) are common along this zone. Pegmatites may or may not be granatic. Because they from late in the crystallization process, they are rich in strange elements. These strange elements aid the formation of multiple minerals Including tourmaline, beryl, topaz, allanite and apatite. Also visible at Enchanted Rock is Xenolith. Xenolith is a section of surrounding rock that broke off and dropped into the granite while still molten. Looking at the rock stretch up towards the horizon is remarkable and is only possible because in the late Seventies, it was purchased by the Nature Conservancy of Texas from a private owner. In 1984 the Conservancy of Texas transferred the land to the state for use as a park. The park can get so crowded on nice weekends that they must close by 11AM. Maps are helpful to lead visitors to points of interest and provide detail on the slope of Enchanted Rock for climbers. ...
