Fossil and recent soil formation in lateleistocene loess deposits in the southern part of the Netherlands.

Abstract

In the younger, Weichselian (Wurm, Wisconsin) loess deposits in the south of the Netherlands there is a horizon with fossil pedotubules (filled animal burrows). These pedotubules, 3 mm ( plus or minus 1 mm) in diameter, unbranched, without preferential orientation, are most abundant in the zone extending from about 30 cm above the decalcification boundary (situated 2-3 m below the soil surface) to some decimeters below it. They are rare in the B3t horizon of the overlying Hapludalf. Their lower extension boundary occurs some 2 m below the decalcification boundary. These tubules result from fossil animal activity followed by decalcification, mainly of a Boelling soil surface. A loess layer some 2 m thick was probably deposited in the post-Boelling period; the lower part of this layer has a lamellae spot zone. Micromorphological evidence shows that the lamellae spot zone was originally at the actual soil surface. Consequently a geogenic origin of the lamellae spot zone rather than a pedogenic origin seems likely. Soil formation subsequently intensified the textural differences. It is suggested that the post-Boelling loess was free of calcium carbonate at the beginning of the Holocene and was deposited non-calcareously or was decalcified synsedimentarily. In Western Europe, loess soils formed from Pleistocene deposits probably matured earlier in the Holocene than has been assumed hitherto. (Abstract retrieved from CAB Abstracts by CABI’s permission)