10,000 years in the life of the river Wandle: excavations at the former Vinamul site, Butter Hill, Wallington JIM LEARY, NICK BRANCH and BARRY JOHN BISHOP with contributions by PHILIP ARMITAGE, CHRIS JARRETT and IAN RIDDLER Archaeological excavations alongside the river Wandle in Wallington produced evidence of the environmental history and human exploitation of the area. The recovery of a large assemblage of struck flint provided information on the nature of the prehistoric activities represented, while a detailed environmental archaeological programme permitted an examination of both the local sediment successions and thus an opportunity to reconstruct the environmental history of the site. The site revealed a complex sedimentary sequence deposited in riverine conditions, commencing during the early Holocene (from c 10,000 years before present) and continuing through the late Holocene (c last 3000 years). Large flint nodules were washed by the river onto the site where they were procured and worked by Mesolithic and Bronze Age communities. Potentially usable nodules had been tested, and suitable pieces completely reduced, while the majority of useful flakes and blades had been removed for use elsewhere. Small numbers of retouched pieces, such as scrapers and piercers, indicate that domestic activities took place nearby. By the Saxon period the site had begun to stabilise, although it remained marshy and probably peripheral to habitation. Two pits from this period were excavated, one of which contained an antler pick. A small quantity of cereal grain also suggests that cultivated land lay in the vicinity of the site. During the 19th century a mill race was dug across the site, redirecting water from the river Wandle, which resulted in episodic flooding. Introduction An archaeological investigation was carried out in 2001 by Pre-Construct Archaeology in advance of the redevelopment of the former Vinamul site (site code BTG01), Butter Hill, Wallington, in the London Borough of Sutton (fig 1; TQ 2825 6520). The initial investigations showed that much of the site had been damaged by modern activities and that it contained localised areas of toxic contamination. However, three areas were identified as having promising sedimentary sequences, and consequently an archaeological excavation followed, comprising trenches A, B and C. The mitigation strategy employed on the site allowed for only one-third of the prehistoric deposits to be excavated. The site lies within the relatively low-lying valley of the river Wandle, immediately to the east of the present course of the river, and the levels of the modern land surface fall steeply towards the river to the west. The archaeological sequence THE EARLY HOLOCENE The earliest deposits recorded during the excavations comprised olive grey consolidated clay, identified as redeposited London Clay (fig 2; fig 3, contexts 35 and 27), which was recorded at a height of between 26.04 and 26.85m OD. The pollen record from these contexts is characterised by high percentages of grass (Poaceae), pine (Pinus) and hazel (Corylus type). These pollen taxa suggest the presence of open pine woodland and hazel shrubland growing on nearby dryland. In wetter areas, the pollen record indicates the presence of open alder (Alnus) and willow (Salix) woodland (fig 7). Though not secured by independent dating, it is Surrey Archaeological Collections, 92, 1–28, 2005