Reformatory And Quanah Granites

Most of the granites of the Wichita Mountains of southwest Oklahoma are biotite- and hornblende-bearing, but in a number of plutons riebeckite and/or aegirine occur locally, and these minerals have also been recognized in granite recovered from boreholes. The most widespread development of aegirine and riebeckite is in the Reformatory granite which lies in the westernmost part of the Wichita granites area. The Reformatory granite comprises parts of the Headquarters Mountain, Quartz Mountain, Flattop Mountain and Soldier's Spring Mountain granites, and is the coarsest of the Wichita Mountains granites, consisting of perthite and orthoclase, a little albite-oligoclase, quartz, a little hornblende and biotite, and up to 4% aegirine and riebeckite. Aegirine-riebeckite granite dykes have been reported from Headquarters Mountain and Quartz Mountain (Merritt, 1958, p. 50). Riebeckite and aegirine also occur in the Quanah granite and associated pegmatites in the eastern Wichita Mountains (Merritt, 1958, p. 51; Ham et al., 1964, Table 8, No. 6). Myers et al. (1981) have revised the nomenclature of the Wichita granites and have classified them chemically; they give a map showing the distribution of the various units (op. cit., Fig. 2); see also Powell et al. (1980, Fig. 1).