Dear Meriel McClatchie,
I know of examples where wet soilsamples have been stored over many years in plastic-bags kept in opaque plastic-boxes in a cool room. Be sure to remove as much air as possible before closing/sealing the bag. It just needs to be checked every two / three years whether the samples are still wet, because especially with thin-walled, cheap plastic-bags it can happen that water-vapor leaves through the plastic and oxygen goes in.
Other colleagues used freezing, but this might be too expensive and appears to be not necessary.
As to the wooden vat: There are many ways of conserving waterlogged wood. Soaking it in Sugar, PEG or Melamin-resin or freeze-drying are just the best known. Every method has its own problems and advantages. Sugar and PEG leave the sample in constant danger of humidity, but it is at least theoretically reversible. Melamin-conservation as used in the Römisch-Germanisches Zentralmuseum in Mainz has great results, yields a strong and light sample that won´t change the color any further and is tolerant of changing air-conditions etc. but it is irreversible. In contrast to PEG it is invisible even under the microscope while PEG fills the vessels. PEG-samples are also quite heavy which makes it difficult to mount samples for restauration and presentation.
If waterlogged wood is just to be kept some years for later analysis it is best to use the same plastic-bag-method as for the soil-samples. A simple basin can be used to improvise a vacuum in the bag. It is possible to ad some fungicide, but it appears to be unnecessary. The problem is: Obviously the soil-chemistry and the species will also influence the result. I have seen wood-samples of ash from a bog that were in bad condition after 12 years and oak from a lake that were in great condition after 25 years...
Hope this helps.
Good Luck
Niels
> Greenwich Museum in England some years ago preserved a Roman wooden
> vat excavated in the 1980's. They soaked it in some liquid for some
> months with the
> result was it changed its appearance and is now black. I would have
> thought there was
> a better way to preserve it - but then I am not a conservation expert. I
> feel it has so changed its appearance that over time it might be thought
> that it was how it looked originally and could be confusing.
>
> Beatrice Hopkinson
>
> >Dear colleagues,
> >
> >
> >
> >I am writing with a question relating to the long-term storage of
> >waterlogged deposits. A colleague here in Ireland, Christina Fredengren, has
> >been excavating an important Late Mesolithic lakeside site (further
> >information available at www.discoveryprogramme.ie - see Lake Settlement
> >Project section). Many of the deposits at the site are waterlogged.
> >
> >
> >
> >Christina took many soil samples during the excavation, and it now seems
> >that there are a number of samples that will not be examined in the near
> >future. A museum here in Ireland is interested in storing these unexamined
> >samples, possibly for analysis at some time in future decades.
> >
> >
> >
> >I am looking for advice on current best practice for long-term storage of
> >waterlogged samples. Would it be better to store the soil samples
> >'untouched', or can we sieve them to reduce their mass? Any advice on the
> >addition of water/alcohol/other materials to enable preservation of the
> >waterlogged remains would also be appreciated.
> >
> >
> >
> >Best wishes,
> >
> >Meriel McClatchie.
> >
>
--
Niels Bleicher
Textorstr. 97
60596 Frankfurt
Tel.: 069 66124984
mobil: 0177-2349074
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