IRON-MANGANESE AND OTHER PANS IN SOME SOILS OF NEWFOUNDLAND

• Published in: Canadian Journal of Soil Science
• Main Authors: McKeague, J. A., Damman, A. W. H., Heringa, P. K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1968
• Subjects: Soil Science; Sola; Newfoundland
• Online Access: http://dx.doi.org/10.4141/cjss68-034; http://www.nrcresearchpress.com/doi/pdf/10.4141/cjss68-034

The thin, dark-colored, cemented layers that occur commonly in coarse deposits under peat in humid coastal areas of Newfoundland were found to be cemented mainly by amorphous Fe and Mn or by Fe compounds. The Mn contents of these pans varied from about 0.1 to 15%, and Mn tended to accumulate in the lower part of the pan. The Fe-Mo pans could be distinguished in the field from Fe or Fe-organic matter pans by the fact that the black layer at the base of the Fe-Mn pans reacted vigorously with cold 3% H 2 O 2 . The Fe-organic pans, which usually had a rusty brown layer at the base, reacted only slowly. The Fe-Mn pans were associated generally with more humid conditions, as indicated by a greater thickness of peat, than those characteristic of the Fe-organic matter pans. We think that reduction, translocation as Fe +2 and Mn +2 and subsequent oxidation and precipitation of mixed hydrous oxides must be involved in the formation of the Fe-Mn pans, whereas translocation and precipitation of Fe-organic complexes are thought to be involved in the formation of Fe-organic matter pans.Many of the Fe-Mn pans occur below organic soils, but they also occur within the sola of some mineral soils. Thus, they should be recognized in soil mapping and accommodated in the soil classification system.