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Climate signals from Hoxne

A new paper by Prof David Horne and colleagues sheds further light on the ‘Arctic Bed’ at Hoxne

The name ‘Hoxne’ has a special place in the lexicon of Palaeolithic archaeology. The brickyard and adjacent pits located near the village of Hoxne in northeast Suffolk have long been famous for John Frere’s discovery in 1797 of several “objects of curiosity”, which later become known as handaxes, and the recognition of their antiquity and significance. More recently John Wymer’s systematic excavations at the site in the 1970s provided a detailed account of the geology, environment and archaeology at the site. It is also an important site for Quaternary geology and biology more generally; Richard West’s classic work on the palaeobotany, published in 1956, provided a detailed assessment of the interglacial vegetation history at Hoxne, and was the basis of the formal definition in 1973 of the Hoxnian Stage of the British Pleistocene. This interglacial is now generally correlated with Marine Isotope Stage (MIS) 11 of the ocean record which dates to around 425,000 to 360,000 years ago.

Schematic section through the Quaternary deposits at Hoxne. The Hoxnian interglacial is represented by strata E-D and the cold interval by Stratum C.

A perhaps less well remembered but no less noteworthy contribution to research at Hoxne is that of Clement Reid (1853-1916). Reid, a geologist and palaeobotanist, and officer of the Geological Survey, is known for his detailed mapping and description of the Quaternary deposits in Britain and elsewhere, and, with his wife Eleanor, was one of the pioneers of the use of plant macrofossils to reconstruct past vegetation changes. Reid directed excavations at Hoxne in 1895 on behalf of the British Association. This work laid the foundations for understanding the site, and established the stratigraphic succession of a series of lacustrine clays (bed E), peat (bed D) and overlying lacustrine and fluvial sediments (beds C-A). Reid identified macrofossils of dwarf species of birch and willow in Bed C, hence the term the ‘Arctic bed’ for this part of the succession, which he regarded as being deposited during a period of cold climate conditions following the main part of the interglacial and succeeded by a further phase of temperate climate conditions when beds A and B were deposited.

A 50cm monolith through part of Stratum C at Hoxne, sampled during AHOB excavations in 2003
A 50cm monolith through part of Stratum C at Hoxne, sampled during AHOB excavations in 2003

One hundred and twenty-five years later, the Hoxne succession has again been investigated for its fossil content and palaeoclimatic significance. A new paper by Dave Horne and colleagues published in Quaternary Research provides quantitative palaeotemperature estimates from three invertebrate fossil groups; beetles, chironomids and ostracods, which are found within the Hoxne deposits, including Stratum (=Reid’s Bed) C. Using the results from the Beetle Mutual Climate Range (BMCR), the Chironomid Transfer Function (CTF) and the Mutual Ostracod Temperature Range (MOTR) methods, a multi-proxy consensus approach was used to reconstruct the temperature variations during the deposition of the Hoxne succession. The results indicate that summer temperatures during the Hoxnian interglacial were similar or up to 4oC higher and winter temperatures were similar or up to 3oC lower than today. In contrast the temperature reconstruction for Stratum C indicates summer temperatures 2.5oC cooler and winter temperatures between 5-10oC cooler than today. A return to more temperate conditions after the deposition of Stratum C, completes the warm-cold-warm oscillation represented at Hoxne. This climate signal can be correlated with sub-stage variations within MIS 11 of the deep ocean record and also provides a palaeoclimatic backdrop for human occupation of the site some 385,000 years ago.

The paper is not available under OA. However, it will be available on QMRO in due course.

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Coastal curios? A new paper explores recent finds on the beach at Happisburgh 

A new paper by Dr Rachel Bynoe, with PAB researchers and three collectors, has recently been published in Journal of Quaternary Science (the paper is available under open access here).

The paper reports on the large collection of ex situ flint artefacts and mammalian fossils found on the beach and it demonstrates the way in which the time spent on the beach collecting Palaeolithic artefacts and Pleistocene fossils can contribute to research knowledge and understanding. The paper explores the material collected by three of the co-authors, Tim Grimmer, Jo Leonard and Darren Nicholas, along a 5km stretch of the Norfolk coast from Happisburgh to Eccles North Gap between 2013 and 2017. A total of 741 artefacts and 157 mammal fossils were included in this study.

Examples of Pleistocene mammalian remains and flint artefacts as found in the study area (all photo credits: D. Nicholas and J. Leonard)
Examples of Pleistocene mammalian remains and flint artefacts as found in the study area (all photo credits: D. Nicholas and J. Leonard): (a) abraded Elephantid bone fragment near the waterline in Area C; (b) fresh handaxe over the Borehole HC exposures in Area A; (c) Bison sp. metacarpal at the shoreline in Area B; (d) Site 1 deposits exposed on foreshore, walking stick showing find‐point of an ex situ artefact; (e) ex situ handaxe in Area A; (f) ex situ core in Area A. [Colour figure can be viewed at]

The collections were made available to the PAB project by the collectors and handed over to Rachel Bynoe for detailed analysis of the lithics and identification of the fossil material. The artefact assemblage is dominated by hard hammer flakes and cores, though there are also eight handaxes. Among the mammal fossils are several specimens that are identifiable to species, including the extinct horse Equus altidens, the mammoths Mammuthus meridionalisand Mtrogontherii, the extinct elk Cervalces latifrons and giant deer Megaloceros dawkinsi. 

Importantly, all the finds were geolocated by the collectors using hand-held GPS devices. The location data was used to map all the finds in GISthe results of which showed some interesting spatial patterning. There are significant concentrations of lithics and fauna in close proximity to the known archaeological deposits at Happisburgh Site 1 and site 3 and in addition there is a substantial ‘hotspot’ at Eccles North Gap, which cannot be linked to any known occurrence of the Cromer Forest-bed Formation. While the concentration is partly the result of being ‘trapped’ up-drift of the most northerly of the Sea Palling rock reefs, it may indicate that there is an outcrop immediately offshore from which the artefacts are being eroded and transported only a short distance onto the beach. The distribution of the faunal finds also shows concentration close to Sites 1 and 3, but again there are other interesting patterns that might suggest as yet unidentified source deposits. 

The handaxe finds are also of interest. Only one, the Happisburgh handaxe, has been found in situ over the last 20 years, and this was associated with the Site 1 deposits. The discovery of several handaxes in the vicinity of Site 3, which has previously been considered as a core and flake assemblage, raises the question of whether they are an additional component of the Site 3 assemblage. Further handaxe discoveries in situ within the Site 3 deposits are needed to verify this. 

The intriguing possibility that there are archaeological deposits immediately offshore at Happisburgh is a question that Rachel Bynoe is currently investigating through her diving survey work with some promising initial findings. Onshore the collecting continues, with a growing band of enthusiastic collectors. More material has been discovered since 2017 and the diligence and persistence of the collectors who return to the beach again and again has been amply rewarded by the creation of a substantial body of information that has contributed to our understanding of this important Palaeolithic locality.