| Abstrakt: |
The integration of buried soils with overlying soils was evaluated by examining base saturation, clay illuviation, and the clay weathering products of soil formation. Base saturation is considered as a rapidly changing characteristic, clay illuviation as slow to change, and clay minerals as most resistant to alteration. The soils studied have loamy or clayey buried B horizons that overlie clastic or limestone rock of Mississippian age. Pedisediment or a zone of mixed loess and pedisediment separates a surficial loess from the buried Sangamon B horizon. Base saturation and fine clay distributions above clayey and loamy Sangamon B horizons show little change through the loess and pedisediment. This distribution of base saturation and fine clay indicates that the pedisediment is integrated with the ground soil. However, where the Sangamon B is clayey, trends in base saturation and fine clay distributions break abruptly at the buried B. Integration of the ground soil with the clayey Sangamon B is not indicated by these properties. When the buried horizons are loamy, there has been post‐loess leaching of bases and illuviation of clay. Apparently, clayey buried Bt horizons retard downward movement of solutes which effectively inhibits post‐loess alteration of the clayey Sangamon B horizon. Amounts and kinds of clay minerals are about the same in the pedisediment and Sangamon B, which indicates that post‐loess integration of the pedisediment has not proceeded to the extent of altering clay mineral suites. |
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