K-feldspar in xenoliths of quartzofeldspathic gneiss at Kilbourne Hole, New Mexico, is sanidine, commonly microperthitic. Cell parameters of a nonperthitic sample (Ог69АЬ27Аn3Сnі) are a = 8.4713, b = 13.0258, с = 7.1712A, β = 116°00′; V = 711.22A3. These cell dimensions indicate a high degree of Al-Si disorder (Z = 2[NAl(T1) — NAl(T2)] = 0.064), one of the highest reported in the literature. The high degree of Al-Si disorder is attributed to the heating of the xenolith when it was incorporated in the basalt, and probably is not a feature of the K-feldspar in the source terrain for the quartzofeldspathic xenoliths.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.