Mr B W Conway of the Institute of Geological Sciences has kindly made the following comments on the geology of the site:

“The causewayed enclosure is sited on the eroded terminal surface of the gravel train of the Upper Floor Plain Terrace at the junction of the Coinè and Thames river valleys (see OS 6 inch geological maps Buckinghamshire 56 SE, 58 NE and Middlesex 19 NE and SE (and Fig 2)). The late Professor Zeuner traced the profile of this terrace and claimed that it grades into the Late Monasirian sea level (7.5 metres) of the latter part of the last interglacial. The Coinè valley Flood Plain joins that of the Thames at Wraysbury and projects into the Thames as a distinct, slightly raised, delta. This delta was formed by the piling up of aggradation by the Coinè beyond the capacity of the Thames to remove it. The presence of this delta was the cause of the breaking up of the Coinè into a series of distributory channels: mainly those of the River Coinè, the Coinè Brook and Wyrardisbury River. These in turn eroded the Cclne delta and the Flood Plain gravel train. Erosion by the several distributory channels left slightly elevated gravel ridges between their valleys and clays, peats, and silts accumulated in these valleys. The eroded remnants of the delta and the Flood Plain Terrace appear as low “islands” of gravel between marshy stream valleys. The Staines causewayed enclosure is sited on the southern tip of the largest of these islands, which is approximately 4km long, has an average width of about 0.4km, and an area of approximately 182.lha.”

Macroscopically this sherd appears to be of a fine sandy ware, with ripple burnish. In thin section it can be seen to be a ferruginous clay with a large number of lumps of colloidal iron. It containes a high proportion of small grained and proportionately rounded quartz particles, and a small number of large, calcined flint particles. From the ID, T10, L2,

The worked stone, other than sarsen, was kindly examined macroscopically by Mr R W Sanderson of the Petrological Department of the Institute of Geological Sciences, and the following notes were compiled from his verbal comments. Apart from the polished stone axes, the majority of the rocks are not very distinctive in type, and except for a few specimens (eg S2, S15, and S20 and possibly S3, S6, and S5), it has not been possible to identify their sources.

Few identifiable fragments of charcoal were found on the site. The samples recovered were all very small and too few in number to determine the frequency of the species present. Dr D F Cutler and Mrs R Gale of the Jodrell Laboratory, Royal Botanic Gardens, Kew kindly examined and identified the specimens from the enclosure ditches and from the interior respectively. The samples from the ditches were all found to be mineralised, and some were compressed. The following species are present:

This comprises a small amount of pottery, together with a few objects of baked clay, spanning the second and first millennia BC. Many of the earlier Bronze Age sherds came from several small features in Area H. There were four main concentrations of Early pre-Roman material on the site, covering Areas C and D, and the south-east part of Areas G and H. None of these concentrations appeared to be associated with any substantial contemporary activity on the site, which is perhaps surprising in relation to the preponderance of such material from other sites in the area (Barrett pers comm).

A quantity of Romano-British material was found in the course of excavation and although most of this was from disturbed contexts an attempt was made to define the nature and period of occupation which it represents.

The principal features dated to this period by material from primary positions are a number of long straight ditches, F138, F225, F225a and F255, running roughly north-east to south-west, and an irregular D-shaped enclosure, F170 (Fig 12). It is suggested that the ditches form the boundaries of a fairly large-scale layout of fields. From the discrepancies of alignment in ditches lying close together it appears that the boundaries silted and were re-cut without much exactitude. Very little stratified pottery could be associated with these ditches: a Flavian sherd from F138 and late Roman wares from F255.

Only three Roman coins varying in date from the late third century AD to about the middle of the fourth century AD were found during the excavations. These came from superficial deposits within the interior of the enclosure, in the area covered by the detailed plans, F, G, and H (see Fig. 5), and are as follows;

The Samian pottery (51 sherds) was found in the Interior of the Enclosure, and is of first and second century date. I am grateful to Mr B R Hartley for discussing certain of the sherds with me.

The provenance of the ware was as follows:- South Gaulish, 8 sherds; Central Gaulish, 42 sherds; East Gaulish, 1 sherd: