Parham, W.E.Hogberg, R.K.2010-04-062010-04-061964Parham, W.E. and Hogberg, R.K., 1964, Kaolin Clay Resources of the Minnesota River Valley Brown, Redwood & Renville Counties, A Preliminary Report, Minnesota: Minnesota Geological Survey Report of Investigations 3, 43 p.0076-9177https://hdl.handle.net/11299/60187Kaolin clays of potential economic significance occur in the upper part of the thick regolith developed on Precambrian crystalline rocks and in overlying shales of late Cretaceous age in the Minnesota River valley, in Redwood, Brown, and Renville counties. Preliminary tests indicate that the clays in the regolith warrant further testing for use as filler and coating clays in the paper industry and for the manufacture of refractories. Ball clays, previously unknown in Minnesota, and a few thin bentonite beds in Cretaceous strata appear to be of limited tonnage but should be investigated further.en-USReport