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Condition of the archaeological deposits

Sediment descriptions

Laboratory descriptions of the sediments examined are presented in Tables 5, 6, 7, 8 and 9. The deposits ranged from very humic material with a silty texture to largely mineral sediments with a substantial clay component. In this, they were very typical of archaeological deposits seen previously in the Coppergate-Pavement area of York, for example at 16-22 Coppergate and 6-8 Pavement (Kenward and Hall 1995; Hall et al. 1983). However, none of the contexts seen in section in Trench 1 was as richly organic and obviously well preserved as many of the pit fills and even some floors and other layers at Coppergate. At the time of the evaluation, it was felt subjectively by two of us (AH/HK) that, on the basis of observations in the field and in the laboratory, some of the deposits had probably decayed from a state like that observed in some of the best-preserved layers at Coppergate. While some of the deposits (especially those from the upper parts of the north-west face of Trench 1, e.g. Context 1004) were distinctly 'jumbled' and clearly represented redeposited material, others were essentially homogeneous and there was little doubt that they were primary pit fills.

The most striking aspect of these deposits, and the characteristic which led to the initiation of the present project, was the macroscopic evidence observed during assessment (and amply supported during the second phase of investigation) suggesting that in situ decay might be occurring: zones of reddening and apparently changes in texture, interpreted as recent oxidation and the precipitation of calcium salts in voids. It is difficult to describe in objective terms the very strongly characteristic nature of certain of these deposits as perceived subjectively - the subtleties of coloration (and its distribution) and of texture which made them stand out from almost all of the very large number of other deposits examined by the authors. Perhaps the most effective way of conveying these subtle impressions is by quoting from the discussion section of the evaluation report (Carrott et al. 1995, 7).

'These conclusions [concerning the history of decay of the remains] drawn from an examination of the fossils are strongly supported by direct observation of the samples of deposits. All of the deposits examined contained organic matter, in several cases in the form of concretions familiar to us from previous excavations as being faecal in origin. Some of these concretions showed signs of oxidation, with voids and the softer-textured areas rather orange in colour. The matrix in which these were contained was soft and spongy in texture, reddish in colour, and will undoubtedly decay to dust very quickly with exposure. Several samples contained wood, and there were four 'spot' finds also of wood; this material was generally very soft on the outside with a brittle core which may have been the result of mineralisation. It is our contention that organic material in this condition could not possibly have survived for nearly a millennium. We have seen deposits in a somewhat similar condition on a few occasions, when we have suspected that there had been recent changes in ground conditions allowing the onset of decay. The present site offers very much the best case for such recently initiated decay, however. There are also strong similarities to some of the samples from 16-22 Coppergate, which were in good condition when excavated but had become distinctly soft and friable in storage, although in [that] case there was more limited colour change and oxidation of fossils.'

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