At Redwood Falls two kilns of brick, about 200 thousand, were burned by Bohn & Lamberton in 1878. The clay is about 40 feet above the top of the succession of falls here in Redwood river, and about 180 feet above Minnesota river. The section is black soil, 2 feet; yellow clay, dipping slightly eastward, about 7 feet; changing below to yellowish sand. This clay is in layers, mostly about 8 inches thick, divided by dark partings similar to those described at Carver and Jordan. The underlying sand is in layers from ¼ to 1 inch thick, separated by hard films of iron-rust. Attempts to make bricks at Minnesota Falls and Granite Falls have failed, because of small limy concretions in the clay, causing them to crack in burning. Bricks in this region command $8 per M [1,000]. (The Geological and Natural History Survey of Minnesota, The Eighth Annual Report for the Year 1879, Submitted to the President of the University, Feb. 18, 1880, The Pioneer Press Company, St. Paul, MN, 1880, Page 120)
Page 587. Bohn & Lamberton, at Redwood Falls, in 1878, made two kilns of red bricks, amounting to about 200,000, which were sold at $8 per thousand. The clay and sand used are a deposit of
Page 588. modified drift, situated near the top of the bluff of Redwood river, on its west side, about thirty rods north of Cook & Co.’s mill, and nearly 50 feet above their mill-pond. The section here is black soil, 2 feet, gradually becoming yellow in the next 2 or 3 feet; thence, compact yellow clay extends to 9 feet below the surface, divided by darker partings into layers from four inches to eight inches or a foot in thickness, which dip 2° or 3° E. These layers are distinctly continuous along the whole extent of the excavation, about four rods. They are probably the depositions of successive years; the finer, dark partings being the sediments of the season of low water; while the great mass of each layer was made by high floods, with stronger currents and bearing more abundant detritus, supplied from the melting ice-sheet during the warm portion of the year. Below the depth of 8 or 9 feet the clay changes to yellowish sand, obliquely bedded in layers from a quarter of an inch to one inch thick, separated by harder films of iron rust. Too much sand was mixed with the clay in this brick-making, so that the bricks were somewhat deficient in hardness and durability; but the clay seems to be excellent for this use. (The Geological and Natural History Survey of Minnesota, 1872-1882, Volume I, N. H. Winchell & Warren Upham, Johnson, Smith & Harrison, Minneapolis, 1884)