Evidence of two temperate episodes in late Pleistocene deposits at Marsworth, UK

Abstract

In the British Quaternary, two post-Cromerian interglacials, the Hoxnian and the Ipswichian, are recognized¹. Evidence of additional interglacials in this interval is widely accepted in the oceanic record of Quaternary events², and the possibility that at least one additional interglacial of this age is represented in Britain has been discussed^3–5. However, in the absence of datable interglacial deposits which are seen to overlie one another, the issue has remained controversial. We describe here deposits at Marsworth, UK (Fig. 1) where there is evidence of two temperate episodes, and of intervening periglacial conditions. Stratigraphical superposition is established beyond any reasonable doubt. The later deposit relates to the temperate woodland stage of the Ipswichian Interglacial. Dating of the earlier temperate material by the ²³⁰Th/²³⁴U disequilibrium method indicates an interglacial episode not previously established in the British Quaternary.