Recovery

The methods for recovering macroremains depend on the type of deposit being excavated. Samples from dry sites can simply be dry-screened to separate the plant remains from the surrounding sediment. Plant remains from wet sites may be recovered by wet-screening, that is, by using pressurized water to wash the sediments though a screen or set of nested screens that divide the material into size grades. Another method, flotation, is Used where charred material is the main form of plant remains. For flotation, large volumes of soil (often 10501) are collected from a variety of contexts. The samples may be the complete fill from a pit or other context or may be a subsample depending on time and budget constraints. In general, all context types at a site are sampled. If a pit is excavated in a deeply stratified site, each pit layer is normally sampled. If the site is a large village with a variety of contexts such as house floors, hearths, storage pits, and refuse dumps, then each of these should be sampled. Once collected, the soil is partially dried. Too much drying can cause the delicate charred remains to break. The soil volume is measured and recorded along with the sample’s location. In the simplest method, bucket decanting, the soil is gently poured into a bucket of water, stirred, and the material suspended in the water decanted through a fine-mesh (usually 0.2 mm) sieve (Figure 1). The suspended material, or light fraction, is trapped in the sieve while the water passes though it. This is repeated until no more material is in suspension. The soil in the bottom of the bucket is then screened through a mesh of roughly 1-1.5 mm. The material caught in this screen is the heavy fraction and will contain small artifacts and plant remains that did not float. In fact, flotation is recommended for the rapid collection of all small items in certain contexts. Both fractions can be placed in separate pieces of cloth that are tied into a self-contained bags, dried and stored for analysis. For processing large volumes of soil, a number of mechanized methods are available but they are all based on the same principle as the bucket-decanting technique.