Earlier workers did not clarify usage as to whether the Courtland was the quartzite at Redstone in the township of Courtland or the quartzite conglomerate near New Ulm. Name applied in this report to the quartzite at Redstone near New Ulm on east side of Minnesota River (according to the geologic map), Nicollet Co, MN in the Lake Superior region. The formation forms a series of scarps and terraces above the river. Is 300 ft thick at Redstone. Maximum thickness not known. The quartzite varies from soft to flinty; it may be cross-bedded; it is composed of crystalline sand grains with silica cement. Some of lower beds are argillaceous. Some of the upper beds are coarse grained (pebble-bearing or conglomeratic). Presence northward form New Ulm noted by boulders of Courtland in glacial drift. Term Sioux quartzite may be applicable to this quartzite. Redstone quartzite (named) applied to same rocks as Courtland quartzite. New Ulm conglomerate, thought by some [unpublished data?] to be the basal conglomerate of the Courtland, is regarded by this author as younger and separate from the Courtland. New Ulm thought to be Cambrian in age. [Age of Courtland not clearly stated. Is older than New Ulm and inferred to be Huronian.]

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