A group of granitic rocks that intrude Tigerton anorthosite (new) here referred to as Bowler granite. Relation of Bowler to other granites in state not determined. First used as map unit in vicinity of Bowler, Shawano Co, WI. Type locality not given. Derivation of name not stated, but apparently named for Bowler, WI. Is shown on geologic sketch map (p. 16). Surrounds and dissects the Tigerton anorthosite. "It frequently has xenoliths of anorthosite in it over a several mile wide zone surrounding the anorthosite. It shows a great variety of textures in western Shawano County, including a fine-grained unit with particles under one millimeter, pegmatite pods and veins with crystals over a foot, and porphyritic varieties with three inch phenocrysts in a ground mass of one eighth to one quarter inch grains. The color varies from a light red to pink, cream white, gray, and dark gray. The composition is variable, even within each textural group. In all outcrops several varieties are present. Where in contact with the Tigerton anorthosite, the Bowler granite frequently shows distinct layering. Age is not stated, but presumed to be Precambrian.

Source: GNU records (USGS DDS-6; Reston GNULEX).