Flotation samples from 16 features at the Fredricks site were analyzed. The data were drawn from one burial pit (Burial 14), two probable burial pits, and 13 pits. Soil samples were drawn from all feature zones in 10 liter bucket-measured quantities. Additional 10 liter samples were taken from fill zones containing abundant visible charcoal. All samples were processed in the field using a device similar to the SMAP machine described by Watson (1976). Light fractions were collected in a U.S. Standard geological sieve with mesh openings of 0.71 mm, and heavy fractions were captured in a 1/16 in mesh screen inside the flotation tank. Each fraction was then dried in the field and transported back to the laboratory for cataloguing and analysis. In addition, several seeds were sorted from waterscreened material and will be mentioned where appropriate but neither included in site totals nor subjected to quantification.
Procedures for analysis approximated those reported in Yarnell (1974). Each sample was weighed and sifted through a series of U.S. Standard geological sieves with mesh sizes ranging from 6.35 mm to 0.21 mm. Material retained in the 2.00 mm and larger screens was sorted completely and weighed (for heavy fractions, only carbonized plant remains in this size category were sorted completely). Material passing through the 2.00 mm screen was searched only for seeds, cultigen remains, and carbonized plant remains not found in the largest size category. Total plant remains quantities in the 1.41 mm, 1.00 mm, and 0.71 mm screens were estimated on the basis of their representation in the fully sorted (2.00 mm and greater) size class. These extrapolated values appear in Table 38; extrapolated weights for plant food remains are itemized in Table 39.
Most of the flotation samples were analyzed completely. However, three heavy fractions contained large quantities of fired clay, rock, soil, and other inorganic material. Since the heavy fractions were not separated into charcoal and non-charcoal components using chemicals or a second washing, these heavy fractions would have been unwieldy and time-consuming to sort by hand. Therefore, in these cases a 50% sample was obtained using a riffle-type sample splitter. Samples treated in this way are indicated in Table 38.
Two primary methods of quantification of plant remains data for comparative purposes were used, namely percentage (by number for seeds and by weight for other types of plant food remains) and ubiquity. Percentage by weight is flawed as a comparative tool for assessing relative importance of various types of plant foods because of differences in durability, preservability, method of deposition, and food-to-waste ratio between these food types. However, percentage by weight (Table 40) does give a rough measure of quantities of plant food remains and can be useful for comparing remains classes with similar preservability (such as hickory shell and walnut shell). Less preservable types of plant remains such as small seeds and acorn shell may appear to be poorly represented on the basis of percentage by weight alone. Ubiquity (as the percentage of features in which a plant taxon is represented) has the advantage as a comparative measure of considering only frequency of occurrence without ranking by quantity and is useful for comparing plant remains classes with different physical characteristics and/or types of remains manipulated differently by people. Densities of plant remains, plant food remains, and seeds in feature fill are given in Table 41 as a quick reference to the concentration of plant remains in different features and feature types.
Seeds are reported by number (Table 42) and weighed as an aggregate for each feature (Table 39). Heavy, durable propagules like nuts and peach pits, which usually occur as fragments, were weighed but not itemized by number. Cultigen remains (common bean, maize kernels and cupules, and cucurbit rind) are itemized by weight as well as number, except for cucurbit seeds, which were weighed together with other seeds. Seed quantities also are expressed as percentage of total identified seeds. Interpretation of the importance of plant foods represented by whole seeds depends upon number of seeds per fruit, durability, and method of preparation as well as on relative or absolute quantities.