Retrieval of Materials with Water Separation Machines

Retrieval of Materials with Water Separation Machines

Sarah E. Peterson
with contributions by Philip P. Betancourt
Volume: 1
Copyright Date: 2009
Published by: INSTAP Academic Press
Pages: 27
https://www.jstor.org/stable/j.ctt3fgvxx
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  • Book Info
    Retrieval of Materials with Water Separation Machines
    Book Description:

    From the introduction: A water separation, or flotation, machine is an instrument that divides soil into three components: the material that floats (called flot or light fraction), the stones and other heavy portions that do not float (called residue or heavy fraction), and the particles that either dissolve in water or become suspended in it and are washed away. The primary purpose for utilizing such a device is the recovery of organic remains, such as charred seeds, charcoal, or small bones, which would otherwise be permanently lost. However, the machine is of great value for archaeological excavation because it allows for the collection of tiny artifacts of all classes, it divides them by size and weight, and it does not break fragile items. Water separation is very different from water screening. Use of a water separation machine requires four stages in the recovery of archaeological material: 1. Retrieval of archaeological sediments 2. Operation of the water separation machine 3. Sorting of the materials 4. Study of the materials Contents: List of figures; Introduction; Goals for Using Water Separation Machines; History of Water Separation Machines; General Components of a Water Separation Machine; Retrieval of Soil; Sorting and Study of Remains; Contamination; Case Studies; Bibliography.

    eISBN: 978-1-62303-129-9
    Subjects: Archaeology

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. List of Figures
    (pp. vii-viii)
  4. Introduction
    (pp. 1-2)

    A water separation, or flotation, machine is an instrument that divides soil into three components: the material that floats (called flot or light fraction), the stones and other heavy portions that do not float (called residue or heavy fraction), and the particles that either dissolve in water or become suspended in it and are washed away (Fig. 1).

    The primary purpose for utilizing such a device is the recovery of organic remains, such as charred seeds, charcoal, or small bones, which would otherwise be permanently lost. However, the machine is of great value for archaeological excavation because it allows for...

  5. Goals for Using Water Separation Machines
    (pp. 2-3)

    One of the primary goals of the archaeologist is the collection of material evidence to aid in the understanding of the past, and the methods by which these remains are collected during excavation will influence these interpretations. If recovery techniques carried out in the field are biased toward larger, more visible remains, conclusions that are based solely on such materials will be incomplete and inaccurate. Additional contextual information, therefore, must be obtained from the collection and analysis of smaller, less noticeable items. Water separation allows for the retrieval of such materials.

    Small archaeological remains that can be retrieved through water...

  6. History of Water Separation Machines
    (pp. 3-4)

    One of the first water separation devices was D.H. French’s so-called Ankara machine, built for operation at Can Hasan III in Turkey. The conception of the Ankara machine and others like it can be credited largely to the sieve experiments carried out by Sebastian Payne in the early 1970s at Can Hasan and several other Mediterranean sites, including the Franchthi Cave and Sitagroi in Greece (French 1971, 59; Pearsall 2000, 22–23). The Ankara machine, whose description was published by French in 1971, was designed to use two main components—a main box into which soil samples were poured and...

  7. General Components of a Water Separation Machine
    (pp. 5-7)

    In the operation of the water separation machine recommended here, water is directed into the lower section of a metal or plastic container called the main tank. Then by some means the water is directed upward through the bottom of a cloth mesh-lined tray into which a soil sample has been poured. The soil is then broken up, and residue that is larger than the holes in the cloth mesh is collected in the tray (Fig. 4). Flot is carried by the flow of water over a sluiceway (large spout) attached to the main tank and is then collected in...

  8. Operation of a Water Separation Machine
    (pp. 8-11)

    Water separation machines are very simple to use. Any individual who has received less than an hour’s training is sufficiently prepared to correctly operate the device. It is not necessary to have a specialist on site to supervise labor; his or her services may only be required during the sorting and studying of resulting material. Provenience data, sample number, volume, and any other information required as determined by the project specialists or director must be recorded before beginning. The calculation of volume can be accomplished by collecting or storing soil in buckets with standard capacities.

    The steps in the operation...

  9. Retrieval of Soil
    (pp. 11-12)

    The objectives of the soil sampling strategy for water separation will vary between excavations, and they should be developed under the guidance of project specialists in order to answer specific archaeological questions. The availability of such resources as funding, labor, and time should also be taken into account. The collection system utilized ultimately will determine the kind, quantity, and quality of interpretative data that is obtained, and it should be carefully planned (Wright 2005, 21). Two methods exist for collection of soil for water separation: bulk collection of all excavated soil and representative sampling.

    Bulk collection involves the systematic retrieval...

  10. Sorting and Study of Remains
    (pp. 12-13)

    Following the processing of soil samples, archaeological materials present in the dried flot and residue are sorted and identified. During sorting, recovered remains are classified primarily based on size and appearance. Students and other unskilled individuals can be employed to sort and initially identify residue samples because a basic familiarity with commonly represented materials is sufficient. New workers should be shown examples of the items that they will encounter, and the instruction of a specialist, material identification manuals, taxonomy textbooks, and comparative collections can be helpful in this respect. A specialist, such as an archaeobotanist, usually sorts through flot samples...

  11. Contamination
    (pp. 13-14)

    Materials can become contaminated at every stage of collection. Soil samples can become contaminated before retrieval by modern seeds or other materials that fall into the topsoil through dry cracks and root holes or as the result of plowing and burrowing. Contamination can also occur if samples are recovered, stored, or transported without care. Some types of ancient remains, such as seeds and other plant parts, are unlikely to survive unless they are preserved by charring or desiccation. It may be relatively simple, therefore, to distinguish modern contaminants from ancient material. Some waterlogged remains, however, may appear to be modern...

  12. Case Studies
    (pp. 14-18)

    The Cretan copper smelting workshop at Chrysokamino was excavated in 1996 and 1997 under the direction of Philip P. Betancourt. The site, which was situated at the top of a cliff overlooking the Aegean Sea, was covered with a pile of slag containing pottery from Final Neolithic to Early Minoan III. The excavation uncovered a small hut and extensive evidence for the copper smelting operation. In addition to the slag, finds included chimney fragments, pieces of ore, a tuyere, part of the wall of a furnace, and pot bellows (Betancourt 2006).

    The program to retrieve materials with a water separation...

  13. Bibliography
    (pp. 19-24)