The Mesoproterozoic intrusive contact between the ~1.1 Ga anorogenic Town
Mountain Granite and the ~1.3 Ga Packsaddle Schist is a gradational contact
exhumed within the Llano uplift. This contact is exposed along the southeastern
margin of the Enchanted Rock batholith in central Texas. Field observations,
hand sample and thin section petrography, and handheld X-ray fluorescence
analysis of hand samples were used to characterize the gradational nature of this
contact at multiple scales. The style of gradation between the Town Mountain
Granite and Packsaddle Schist varies throughout the study area, containing both
injection and permeation. The complex relationships observed at the contact
possibly resulted from variations in temperature conditions along the contact at
different stages of the emplacement.
Galle, Travis, "Petrology of the Gradational Intrusive Contact Between the Packsaddle Schist and the Town Mountain Granite, Enchanted Rock State Natural Area, Llano Uplift, Central Texas" (2020). Student Publications. 2.