Kaolinite-enrichment beneath coals, a modern analog, Snuggedy Swamp, South Carolina

Abstract

Abstract The Snuggedy swamp contains peat deposits up to 100 inches (250 cm.) thick underlain by about 10 inches (25 cm.) of rooted and unbedded clay. This clay has a kaolinite/montmorillonite ratio of more than 2/1 and a pH less than 5. On the other hand, the clay below this zone, or where the peat is absent, is bedded, contains no roots, has a kaolinite/montmorillonite ratio below 1, and a pH greater than 5. There is strong evidence to suggest that the clay zone immediately beneath the peat was not kaolinite-rich when deposited, but was enriched due to leaching by humic-acid solutions which filtered down from the peat. This phenomenon may be similar to the formation of underclays below certain Paleozoic coals.