Chapter 4: Excavations, Archaeological Stratigraphy, and Cultural Components
Michlovic, Michael G., Plains Anthropologist
EXCAVATION AND CULTURAL COMPONENTS
Excavations at the Rustad site were conducted in three areas (see Figure 1.4 in Chapter 1), each consisting of a number of adjacent 1 × 2 m units. Area 1 was in the southeastern portion of the quarry pit and comprised about 112 m^sup 2^. Area 2 on the west side of the quarry included about 40 m^sup 2^. Area 3 was made up of 14 m^sup 2^ placed in the northeastern wall of the quarry. It consisted of two disjunct portions of the eastern wall of the quarry, called 3 A (north) and 3B (south). Two units helped to determine the eastern and southern site boundaries; XU-8 in the southern and central portion of the quarry, and XU-80, opposite a gully on the eastern side of the site, were culturally sterile units. The western boundary is a deep ravine immediately west of Area 2, and the northern boundary is visible in the eastern quarry wall where the buried A horizons disappear, only a few meters south of the gravel road on the north side of the site.
Units were excavated in 5 cm levels, numbered sequentially from the beginning of each unit excavation. Levels were interrupted to conform to changes in natural stratigraphy. The exception to this was the excavation of units 1-11. These units were laid out on a grid the first season at the site (consisting of four days work). The cultural layers were shovel scraped and no levels maintained. The reasons for this are explained in the introduction.
The Rustad site contains three components. The major component is Early Archaic and consists of artifacts, bone, and features in Layers 5 and 6. It has an average radiocarbon age of about 7450 B.P. Paleoindian materials are present in much lower frequencies in the deeper Layer 9. This Paleoindian component may partially superimpose itself in a few units, a situation that is explained below. The Paleoindian is only found in Area 1, and it is dated to between 9000-8400 B.P. A Woodland component is recognized in eolian sands only in Area 2. This component has not been dated, but it is defined on the basis of two potsherds, a projectile point, lithic and bone debris, and an ash stain. The most important component, and the focus of the greatest archaeological effort at the site, was the Early Archaic. This component occurs in all three areas and in all units that contained cultural material (Figure 1.4).
STRATIGRAPHY (Figure 4.1)
Natural horizons and strata at the site were given archaeological layer designations (Table 4.1). This was done in each of the areas where excavations were conducted. Sandy and silty sediments above the occupation were designated Layers 1-4 based on color variations. Layer 1 was excavated in a few southern units in Area 1. Layers 2 and 3 were most commonly encountered above the main living floor. Layer 4 was a thin layer (l-2cm) found in some of the Area 1 units. None of these are believed to be culture-bearing layers, and the few artifacts and animal bones found in them were probably displaced from Layers 5 and 6. Layers 1-3 were generally removed without level control. Layer 4 was excavated and screened with normal controls since it was so close to the artifact-bearing levels. This procedure was adopted to save time for the excavation of the archaeologically rich layers below.
The main archaeological occupation was originally identified as Layer 5, a conclusion that later had to be modified. In places where Ab2 and Ab3 were recognized as separate, Ab2 was called Layer 5 and Ab3 was defined as Layer 6. After exposure Layer 5 in Area 1 appeared to have a dark gray color contrasting to the black or very dark gray color of Layer 6. In Areas 1 and 3 a Layer 5b was defined as the relatively thin, light colored (pale brown) and culturally poor layer between 5 and 6. In Area 1, Layer 5b was found in only a few units on the eastern side of the excavation, while it was observed in all units in Area 3. In most of Area 1, and all of Area 2 it was impossible to distinguish Layer 5 from 6 (Ab2 and Ab3). …