Kern Knob Granite. Leucocratic, medium-grained biotite monzogranite having a hypidiomorphic inequigranular texture. Includes sparse biotite, muscovite, fluorite, hematite, and garnet. Contains dikes and pegmatite lenses. Recognized only at Kern Knob [Haystack]. Previously called Kern Knob pluton by Griffis (GSA Cordilleran Sec. Gdbk, Trips 2 and 14, 1986; California State Univ. MS thesis, 1987). Age is Late Cretaceous. Biotite Ar-Ar plateau age ~ 91 Ma (Griffis and others, 1986, GSA Abs. w/ Prog., v. 18, no. 2).
Type locality: a small quarry at the northern base of Kern Knob [now Haystack], in SW/4 NE/4 sec. 19, T. 15 S., R. 37 E., [approx. Lat. 36 deg. 37 min. 04 sec. N., Long. 117 deg. 59 min. 37 sec. W.], Dolomite 7.5-min quadrangle, about 500 m east of the boundary with the adjacent Lone Pine 15' quadrangle, Inyo Co., central eastern CA. Named from prominent hill at western base of Inyo Mountains, originally called Kern Knob.

Source: Publication.