Ferricrete is a hard, erosion-resistant layer of sedimentary rock, usually conglomerate or breccia, that has been cemented into a duricrust by iron oxides. The iron oxide cements are derived from the oxidation of percolating solutions of iron salts. Ferricretes form at or near the land surface and may contain non-local sediments that have been transported from outside the immediate area of the deposit.
- alluvial iron oxyhydroxide-cemented conglomerates along old stream channels;
- colluvial iron oxyhydroxide-cemented, poorly sorted breccias with massive to minor layering subparallel to hillslopes;
- iron spring and bog deposits with few or no clasts, exhibiting fine, horizontal lamination; and
- manganocrete deposits with gray to black matrix containing abundant manganese oxide minerals.
- Dictionary of Mining, Mineral, and Related Terms, 2nd Edition. American Geological Institute in cooperation with the Society for Mining, Metallurgy, and Exploration, Inc., 646 p., ISBN 0-922152-36-5.
- Verplanck, Philip L.; et al.; Ferricrete Classification, Morphology, Distribution, and Carbon-14 Age Constraints in Environmental Effects of Historical Mining, Animas River Watershed, Colorado, US Geological Survey, Professional Paper 1651, 2007, p. 726 PDF