A contour map of part of the basin of the glacial Lake Pickering was constructed from surface and sub-surface levels. This map (figs 2, 3 and 4) gives a pictorial representation of the microtopography of the area and is amplified by an additional map (fig. 13) in which the margin of the organic deposits is given for the early Mesolithic period, based on evidence outlined below. A stratigraphical survey of the basin deposits shows that the infilling of the lake in the Devensian Late-glacial began largely with the deposition of calcareous muds. In the early Flandrian there followed a natural hydroseral development from open water to reedswamp and fen carr. Towards the end of the Boreal period and during the early Atlantic, a rise in water level was responsible for the replacement of fen carr by reedswamp. The rate of hydroseral development was affected by a progressive rise of water level. This has been determined (estimated) by radio-carbon dating the basal organic muds on the 23, 24 and 25 m OD sub-surface contours at eight sites within the study area. During the early Mesolithic (Godwin's pollen Zone IV, c.9600 BP)the water level in the basin was likely to have been in the range of 23–24.5 m OD. By reference to the dating evidence, including published pollen diagrams (Walker and Godwin 1954) and new data presented in Parts 2 and 3, the stratigraphical evidence is interpreted to show that there was considerable variation in the vegetation of the lake margin during the early Mesolithic period (pollen Zone IV). At Seamer Carr there was a large area of fen carr woodland with reedswamp fringing the open water. Star Carr had a much larger area of reedswamp, with open water close to the dry land in places, but with a narrow fringe of carr. The bed of the ancient River Hertford, which drained the basin, probably in the late Mesolithic, has been identified in two of the sections which traverse the basin.

A three-dimensional study of the vegetational history of Seamer Carr from the Devensian Late-glacial to the Atlantic period has been made with the aid of six sites in the main basin. Five of these are close to the margins of the organic deposits and the sixth is from deep basin deposits. The Godwin zonation scheme has been used to allow a direct comparison with the survey of Walker and Godwin (1954). A composite section through the basin deposits, based on the detailed contour plan described in Part 1, shows that, pre-Zone IV, the open water margin abutted the dry land, and that during Zone IV reedswamp and carr gradually filled in the edges of the lake. Large expanses of fen carr occupied Seamer Carr during Zone V, but a rise in water level during Zone VI was responsible for the area reverting to reedswamp. At the Boreal/Atlantic transition, coincident with the rise in the alder pollen curve, there is a thick band of highly humified, acid peat, full of microscopic pieces of charcoal. Analysis through this band at one of the specially selected sites on East Island produced evidence of local disturbance, seemingly anthropogenic, at the wetland margin. There were two other special sites in West Embayment that were sampled for pollen analysis. The first was located over a radiocarbon dated Zone II organic deposit, sealed beneath a Zone III calcareous sand layer. The second was located in a late Mesolithic organic mud radiocarbon dated to c. 8000 BP and containing an assemblage of microliths of late Mesolithic type, identified tentatively as a composite tool (A. David pers. comm.).

Detailed boring records and surface levels, combined with knowledge of the rate of extension of organic deposits in the lake basin (Part 1), allow the production of a computer-generated contour map and isometric drawings of the microtopography of the area around the Star Carr site of Clark (1954) (figs 1 and 2). The site was at the mouth of a shallow gully on the southern face of a hillock of glacial till which could be reached from the higher ground to the N over dry ground. The hillock extended into the lake basin as a low peninsula ending in a spit, at the entrance to its relatively narrow outflow channel. The occupation area was at a point where the open water most closely approached the shore and extended from the marginal wetland on to the dry slopes of the hillock.

Pollen and lithological analysis, combined with extensive C14 dating, is described at four closely spaced points along a section through the basin deposits close to the Star Carr site. Dated sequences of local vegetation development are established. The results are used to reconstruct pictorially the environmental changes through a period of occupation contemporaneous with, and presumably an extension of, the occupation of the Star Carr site (fig. 9). The dry ground supported birch wood throughout, but natural successional changes in the wetland, on a nominal timescale, were as follows:

(a) At 9800 BP the open water of the lake lapped the shore save for a narrow zone of reeds, sedges and water plants.

(b) By 9650 BP immediately before the occupation, reedswamp dominated by the great reed (Phragmites) had extended well into the basin. There was a narrow drier zone at the landward side of the reedswamp with abundant ferns enclosing a damper patch with fen plants.

(c) At the time of the occupation, around 9600 BP, the inshore reedswamp had largely been replaced by fen dominated by the saw sedge (Cladium). The marginal environment, where artefacts were found, was still dominated by ferns but a wood layer occupied the former damp fen area, presumably having been deliberately emplaced to consolidate the ground. Cladium fen and fringing reedswamp formed an extensive tract to the E of the occupation area behind the spit mentioned above, and probably also to the W.

(d) By 9300 BP (on the nominal timescale used for the reconstruction) the occupation was over and the wood layer and an associated ‘brown layer’ were covered by Cladium deposits on which willows were now growing.

Attention is drawn to the need for detailed work on the taphonomy of artefacts as a component of any further excavation in the organic deposits of the Vale of Pickering.

The inception of the Neolithic has always been one of the more vexed questions of British prehistory. As an issue, it has been obscured by a number of conceptual difficulties. Not least amongst these is that the transition from the Mesolithic to the Neolithic coincides with the point at which two different and opposed approaches to prehistory and its teaching meet. The first of these, which dominates the study of the Palaeolithic and Mesolithic periods, is concerned with human behaviour in terms of adaptive responses to environmental pressures. The latter, more common in the Neolithic and later periods, is more likely to consider human beings as purposive subjects, acting in pursuit of socially-defined goals. As a result, the Mesolithic-Neolithic transition represents not merely a change of lifestyle, but also a point at which our perception of the past changes. It is the boundary between two models of man.

Material culture meanings are transferred between objects on the basis of similarities and differences. In order to fix the potential ambiguity of meanings, experience is bracketed within bounded contexts. New acts always refer back to existing organized experience or texts. It can be argued that text comes before action. This idea is used in a discussion of the appearance of agglomerated and bounded settlements in the European Neolithic. It is shown that occupied settlements are often preceded by non-domestic enclosures which sometimes have a ritual nature. Ritual text seems to prefigure practical event. A similar relationship between formalized ritual texts and social action is shown in a wide range of other examples. Finally some of the potential reasons for the observed relationship between text and action are discussed.

Aerial survey in Essex has revealed a number of elongated enclosures interpreted as either long barrows or mortuary enclosures of Neolithic date. Excavation of one of these sites at Rivenhall in 1986 produced finds of flintwork and pottery which help to substantiate this hypothesis. A surface collection survey of the field containing the enclosure produced Mesolithic and Neolithic flintwork. A short discussion considers the Essex sites in their wider context.

The environmental setting of two late-prehistoric enclosures in upland Ardudwy, Gwynedd was investigated by pollen analysis of nearby valley mire deposits and of old ground surfaces revealed during excavation of the sites. Radiocarbon-dated pollen data indicate human influence on the local environment since Mesolithic times, with the major period of woodland clearance in the early Bronze Age. The two enclosures appear to have been constructed in an environment already substantially deforested. Remanent upland timber resources appear to have been substantially depleted during occupation of the sites, whilst soil acidification and/or climatic change may also have contributed to their eventual abandonment.

Two late prehistoric circular enclosure settlements near Harlech, Gwynedd were excavated by the Gwynedd Archaeological Trust in 1980–81 in advance of upland pasture improvements. Both produced evidence for the change from timber to mainly stone as a building material, commonplace in upland Britain at this time. At Moel y Gerddi there was some evidence for earlier activity in the Neolithic period, but the principal occupation occurred in the mid-first millennium BC, and comprised a roughly circular timber palisade enclosing a fairly substantial timber roundhouse. As these structures deteriorated, they were consolidated and embanked with stone, but despite this the occupation did not last very long and the site was abandoned. Erw-wen a short distance away produced similar evidence but there was no Neolithic phase and the site was re-used in the Medieval period. The principal late prehistoric settlement there comprised a single large roundhouse standing within an imposing enclosure wall but whether or not this had been preceded by a timber palisade is not known. It was clear, however, that the stone roundhouse was a replacement for an earlier timber counterpart and, quite unlike Moel y Gerddi, the occupation lasted a considerable period of time, possibly two or even three centuries. Dating evidence from either site was poor, and acid soil conditions mitigated against the preservation of most finds. The sites were apparently aceramic and probably relied on pastoralism rather than arable farming. The environmental setting and background has been considered in some detail in the preceding paper with particular reference to soil pollen studies and a bog core dug near Moel y Gerddi. Typologically the sites belong to the Gwynedd stone-built hut-circle settlements and it is argued that they could mark the first appearance of these monuments in the landscape. But in any case, the use of timber as witnessed here, was far more commonplace than has previously been supposed on these sites.