Properties and genesis of a soil and the underlying gibbsite-bearing saprolite, Cape Breton Island, Canada

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Abstract
Brownish yellow saprolite derived from granite gneiss is exposed beneath 1–2 m of reddish brown till along a roadcut in the Cape Breton Highlands. The strongly acid soil is similar to other Podzolic soils of the region except for the presence of gibbsite in the silt and clay fractions. In the saprolite, feldspar and biotite have weathered to poorly crystalline kaolinite, gibbsite, and a minor component of iron oxide. The poorly crystalline kaolinite does not occur in the overlying till.The evidence presented is consistent with the view that the area was covered either by "cold-based" or by stagnant "warm-based" glaciers that eroded the pre-Quaternary surface only slightly and deposited a thin, discontinuous veneer of till derived mainly from local bedrock and saprolite. Weathering products from the saprolite are probably incorporated commonly in tills of the area. During the formation of soils in these tills the poorly crystalline kaolinite and most of the gibbsite are either transformed to other minerals or dissolved and removed in solution.