Middle Pleistocene stratigraphy in south-east Suffolk

Abstract

A conspicuous horizon of rubification, clay and iron enrichment, involutions and ice-wedge casts is attributed to two stages of soil formation. It comprises a rubified sol lessivé formed in warm temperate conditions, which was altered to an arctic structure soil by periglacial processes. These palaeosols indicate that the sand and gravel deposits beneath the Lowestoft Till comprise two units, and provide the basis of a revised Middle Pleistocene stratigraphy. The Kesgrave Sands and Gravels were formed during the Beestonian in a periglacial environment by a major river which drained towards the north-east. Subsequently the Valley Farm Rubified Sol Lessivé was formed during the Cromerian Interglacial, and the Barham Arctic Structure Soil and the associated Barham Loess were formed during the early Anglian Glacial. Both soils and the wind-blown sediments were formed on low relief terrace topography and are the remnants of a formerly extensive land surface. This feature was subsequently trimmed by meltwater rivers, then overlain by the Barham (outwash) Sands and Gravels and the Lowestoft Till which were deposited during the Anglian Glaciation.