This granite is one of a series of exposures that occur along the Pedernales River well to the south of most Precambrian exposures (On the figure in the TMG write-up, they're the tiny pink dots south of the area labeled "Grape Creek"). This granites have a different appearance than seen elsewhere in the Llano Uplift. Note the slight bluish tinge to the quartz. The exposures are the tops of paleo-monadnocks that are completely surrounded by Paleozoic rocks. These granites may be part of the Grape Creek Pluton, but the appearance and mineralogy of the Pedernales granites are very different from the Grape Creek granite. I suspect the Pedernales granites represent a separate unnamed pluton that is almost completely covered by Paleozoic rocks.