n.1.Limestone containing a large percentage of iron carbonate, and hence turning brown on exposure.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
The carbonate cements in Es1 sandstones were mainly calcite; those in Es2 sandstones calcite, dolomite, ferrocalcite, and ankerite; those in Es3 sandstones mainly ferrocalcite and ankerite; and those in Es4 sandstones mainly dolomite and ankerite.
Carbonate cements of the fourth stage (Cc4) were euhedral fine crystalline ferrocalcites and ankerites, lying on the outer part of kaolinization feldspar or secondary pores dissolved by Cc3 (Figures 6(g) and 6(h)).
Zhang, "Distribution and origin of ferrocalcite cements in Paleogene overpressure sandstones on the south margin of Junggar Basin, Xinjiang, China," Journal of Chengdu University of Technology.