Taylor Creek high-silica tin-bearing rhyolites are found in the northern Black Range of the Mogollon-Datil volcanic field in southwestern New Mexico, occurring near the stratigraphic top of a thick mid-Tertiary volcanic section. Initial ɛ_Nd values for the high-silica rhyolite lavas range from −5.0 to −6.2, which are similar to those of the Garcia Camp tuff, a pyroclastic phase of the Taylor Creek Rhyolite. The older Kneeling Nun tuff, which crops out in the same area, also has a similar ɛ_Nd1 value, which indicates that the high-silica rhyolites and spatially associated silicic tuffs were derived from an isotopically...