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2017-08-31 06:52:27 • ID: 1653
Swanscombe during the Hoxnian
It is one of the most famous Paleolithic sites in Europe, preserving an exceptional succession of fluvial deposits and Paleolithic "industries", as well as three conjoining fragments of a human cranium assigned to Homo Heidelbergensis.
The site was noted as early as 1883 by Spurrell. The first systematic excavation took place in 1912, followed by many others until the 1990ies. The most important parts of the Swanscombe sequence are entirely assigned to the Hoxnian.
The Hoxnian Stage is a middle Pleistocene stage of the geological history of the British Isles. It precedes the Wolstonian and follows the Anglian Stage. The Hoxnian is suggested to be equivalent to MIS 11, which started at ca 422 k.a. and ended 380 k.a. ago.
The climatic signal of MIS 11 is well-documented in marine and ice-sheet isotopic records and is known to comprise at least two major warm episodes with an intervening cool phase. The main parts of the Swanscombe succession are:
- Lower Gravel, Lower Loam: Pollen zone Ho I with temperate climate. Possibly the Lower Gravel may, in part at least, date to an earlier stage, but the Lower Loam is usually accepted as a truly full interglacial deposit of Hoxnian date.
Its top is a weathered palaeosol, so a considerable hiatus is inferred before the lower and upper Middle Gravels accumulated on top of it. - Lower middle Gravel: Hol III b-c with temperate climate and the Upper middle Gravel: Hol III b-IV with cool climate. The Middle Gravels began to accumulate not before the end of the late-temperate substage of the Hoxnian, and probably extend into the early-glacial substage of the succeeding glaciation.
- The Swanscombe Upper Loam, a decalcified and oxidized clayey silt is capping the interglacial sequence at this locality
The British evidence suggests that humans during the Hoxnian rather avoided lake-edge situations, but were exploiting the river valleys. The open nature of river valleys was better suited to humans.
Equally, there was a greater variety of resources, in terms of plants, animals and lithic raw materials. Finally, they acted as open corridors through the otherwise dense forest, having good accessibility and being easily navigable, and as prominent features in the landscape were simple to relocate.
It has been suggested that the absence of handaxes at certain horizons at some MIS 11 sites does not reflect a non-handaxe cultural tradition—the Clactonian—but merely reflects the differential distribution across the landscape of different knapping practices by humans with a varied technological repertoire including Handaxes.
This interpretation has, however, been questioned by others, mainly because there is no unequivocal evidence of handaxe manufacture in primary context Clactonian horizons in southern Britain, although the raw material at these sites was perfectly suitable for handaxe manufacture.
The pointed artifact, displayed her comes from the middle gravels at Swanscombe and shows the typical pointed appearance of the majority of the bifaces that were found in the strata with the famous Hominid remains. Further studies on the handaxe ensemble showed, that there is no indication that the preference for pointed shapes could be related to either the shape or source of raw material.
The famous Swanscombe human fossil remnants consisting of three conjoining large cranial bones (two parietals and an occipital) of a young female found in in the middle gravels in 1935, 1936, and 1955 and therefore later than the pointed handaxe displayed here.
The upper loam bears a handaxe industry with twisted ovates. Assemblages with concentrations of twisted ovates in Britain appear to demonstrate a strong chronological correlation toward late MIS11/ early MIS10.
Twisted ovates are virtually absent from sites of a pre-Hoxnian age, such as High Lodge, Boxgrove or Warren Hill. They also do not appear to occur in significant numbers in assemblages younger than MIS 11/10, such as those recovered from Purfleet, Wolvercote and Furze Platt, but they are known from OIS 9 and 8 from Nothern French Acheulian sites-see 2080
Other stratigraphies of Britain show that Handaxes were already present during much earlier times than the Clactonian ensembles at Swanscombe and that the succession of a „Clactonian” -- “Acheulian” with pointed handaxes -- Acheulian” with ovates s not an overall trend, but a singular (random) succession at Barnfield Pit.
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