Sampling Guidelines

S Carter. 2002.

Notes from a site visit by S Carter, 26/06/02

General potential for palaeoenvironmental information.

We discussed what potential there was (if any) for the recovery of palaeoenvironmental information.

  • most sediments are of mineral composition so survival of organic material is improbable. Carbonised plant remains could be present but have not been seen so must be rare. Bone may survive where limestone is present in the gravel.
  • the dark upper fills of the two parallel pit alignments appear to be organo-mineral. However, they are now dry, oxidised and highly humified. Potential for macroscopic plant remains/beetles and even well-preserved pollen is very low. (NB these sediments may be suitable for C14 dating.)

Recommendations for sampling

Bulk sediment samples

Given the absence of evidence for concentrations of carbonised material and a lack of settlement/refuse type deposits, the value of bulk sediment sampling is low. It would be helpful to collect representative samples from each type of feature to support the field evidence for the absence of carbonised plant remains. Processing of the samples may reveal subtle differences between features or simply confirm the lack of material. Collect 2 x 30 litre samples from each pit alignment and the ditches and 1 x 30 litres from each ring ditch.

C14 samples

If low concentration of carbonised plant remains are recovered from bulk samples they are unlikely to be suitable for C14 dating. If the upper fills of the two parallel pit alignments prove to contain organic matter they may be suitable for dating. If these fills represent the gradual infiling of the pits, the base of the organic fill should be close in date to the cutting of the pits (assuming no re-cuts, see below). Potential problems include modem root growth, mixing by worm burrows and oxidation of organic matter (leaving insufficient for dating). Recommend collection of stack of 2 cm spit samples from two pits to allow for dating of various levels in deposit. This will provide a check on mixing.

Kubiena Tin samples

Feature 216 shows evidence for re-cutting in its fills: multiple lenses appear to be cut through down one side of the pit fill. Three Kubiena Tin samples have been taken to allow more detailed examination of these lenses and the apparent re-cut. Determination of the process of deposition of these sediments may confirm or refute evidence for a re-cut and explain why the pit displays a distinctive sedimentary sequence.

Summary of action

  1. Bulk samples: collect, process and assess
  2. C14 samples: collect, store dark and cold, confirm suitability of samples for dating with C14 lab, obtain c. 3 dates from each pit (base, near base and higher up)
  3. Kubiena samples: store dark and cold (with SC), impregnate blocks a.s.a.p. Prepare and analyse sections (SC to provide quotation)

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