Olivine is widespread in samll grains in the Keweenawan gabbroic and basaltic rocks in the county. 30 and NE NE Sec. SW SW Sec. R.1W and NW NW Sec. Olivine bearing rocks are exposed in the NW SWSec.
Associated minerals are plagioclase, orthopyroxene and clinopyroxene.
R.1W such as in the SW Sec. 3, the NE SE Sec. 10 and the SE SE Sec. Similar outcrops occcur in Sec.