Julie K. Stein

Earthworm Activity: A Source of Potential Disturbance of Archaeological Sediments

for most archaeologists. Rodents move through strata accumulating their backdirt at the surface. Tree roots penetrating downward can be ripped up if the tree is blown over. Differential freezing and thawing transports large objects upward, while ants and some earthworms are capable of transporting the same material to lower levels. Wind, water, and gravity scatter material in every direction, while catastrophic events such as earthquakes can completely obliterate any original order. Human activity (plowing, excavating) is often the most powerful force of disturbance. Wood and Johnson (1978) have described nine types of disturbance that affect archaeological deposits. One type of disturbance, faunalturbation-the mixing of sediment by animals (Thorp 1949)-is commonly observed in archaeological profiles as networks of abandoned animal burrows. A burrow, after abandonment, fills with material from another soil horizon. Differences in soil texture and color allow the feature to be easily recognized. But some animal burrows are so small that

6 – Deposits for Archaeologists

Publisher Summary This chapter presents an approach to decipher depositional histories. A useful approach to decipher depositional histories would be to treat the record (in its entirety) as a sedimentological deposit. All components could then be described in sedimentological terms (attributes) and according to the rules established in the geological code of stratigraphic nomenclature, which would allow the archaeologist to determine the contribution of biological (cultural) agents and natural agents in archaeological deposits. A sedimentological deposit is a single sedimentation unit formed under essentially constant physical conditions with constant delivery of the same material during deposition. The material contained in the deposit is called sediment. Each individual sedimentary particle can have a unique depositional history related to its source, transport agent, environment of deposition, and postdepositional alteration. Attributes of the sedimentary particles that can be used to interpret depositional history are texture, composition, and structures. Sedimentary particles are grouped in deposits because the sources, agents of transport, and depositional environments were constant for a sufficiently long period of time to allow them to accumulate.

Coring Archaeological Sites

The history of coring and augering at archaeological sites is traced to two periods in the twentieth century. In the first period, Period I (1935-1955), the technique was used primarily to correlate archaeological deposits with river sediments for dating purposes. Rarely were the deposits containing artifacts cored or augered; rather the stratigraphic relationship of cultural to non-cultural deposits was sought. Most of this work was done in the Lower Mississippi River Delta where geologists had calculated absolute dates for river deposits. This period seems to have ended with the availability of radiometric dating and was followed by Period II (1964-present). After 1964 there is a renewed interest in coring and augering, mostly following a shift in archaeological research interests from culture history toward ecological questions. This shift coincides with the availability of a new device: a mechanical corer. During Period II, coring is utilized in many different projects, including reconstructing the environment surrounding sites, collection of samples from subsurface deposits, and locating buried archaeological sites. Following the discussion of the history of coring and augering, a description of equipment, techniques, and data potential is presented.

Building Confidence in Shell: Variations in the Marine Radiocarbon Reservoir Correction for the Northwest Coast Over the Past 3,000 Years

In many regions, fluctuations have occurred through time in the local 14C activity of seawater. Evaluating these shifts and their effects on 14C age estimates is difficult, and, as a result, archaeologists working in coastal settings tend to preferentially date charcoal samples over shell. Our research on 18 charcoal–shell pairs from Puget Sound and Gulf of Georgia archaeological sites helps elucidate the spatial and temporal dynamics associated with marine reservoir effects in the Pacific Northwest. This analysis suggests that between 0 and 500 B.P. the regional correction value (ΔR) is 400 years, which agrees with the modern value determined by Stuiver and others. Between 500 and 1200 B.P., however, ΔR dips close to zero, possibly reflecting a decrease in offshore upwelling. From 1200 to 3000 B.P., ΔR returns to 400 years. These data are presented as a Puget Sound/Gulf of Georgia regional correction curve for the late Holocene, which local researchers may use to calibrate dates of marine shell. In addition, we detail our methods for constructing calibration curves and present guidelines for archaeologists working in other coastal settings to develop calibration curves for their regions.

A Review of Site Formation Processes and Their Relevance to Geoarchaeology

Someone unfamiliar with the history of archaeological methods and theory who read the title of this chapter would guess that the content addresses the processes responsible for the formation of archaeological sites. That guess would be based on the English use of the word “formation”; an act of giving form or shape to something, or of taking form. The word formation in archaeology, however, has a connotation that goes well beyond this English definition.

Evidence for a Cultivar and a Chronology from Patterned Wetlands in Central Veracruz, Mexico

The patterning found in certain wetlands of lowland Mesoamerica has added an important element to the subsistence system that may be attributed to pre-Hispanic inhabitants of the region. The form of the remains, largely expressed in terms of surface vegetation, suggests agriculture on planting platforms, separated by canals. The physical and chemical aspects of the stratigraphy have clarified depositional environments but have not indicated agricultural horizons. Maize phytoliths at about 1 meter below the surface in two Central Veracruzan wetlands do confirm the practice of agriculture. Associated ceramics indicate wetlands agriculture was practiced by A.D. 500 and perhaps earlier.

Earthquake‐induced burial of archaeological sites along the southern Washington coast about A.D. 1700

Although inhabited by thousands of people when first reached by Europeans, the Pacific coast of southern Washington has little recognized evidence of prehistoric human occupation. This apparent contradiction may be explained partly by geologic evidence for coastal submergence during prehistoric earthquakes on the Cascadia subduction zone. Recently discovered archaeological sites, exposed in the banks of two tidal streams, show evidence for earthquake-induced submergence and consequent burial by intertidal mud about A.D. 1700. We surmise that, because of prehistoric earthquakes, other archaeological sites may now lie hidden beneath the surfaces of modern tidelands. Such burial of archaeological sites raises questions about the estimation of prehistoric human population densities along coasts subject to earthquake-induced submergence.

Coring in CRM and Archaeology: A Reminder

Corers and augers have become increasingly useful in archaeological investigations, but more in cultural-resource management (CRM) than in research archaeology. Although this increase is evident, coring and augering were used in the earliest CRM projects in the 1970s and merely have gained in popularity in the last five years. Schuldenrein (1991) points out that of all the coring and augering equipment described, the manual bucket auger with a large-diameter barrel is of special value. However, one major disadvantage is that sediment is disturbed during extraction, making observations about soil structure and stratification difficult. The disadvantages have to be balanced against the fact that bucket augers are more versatile than corers and penetrate many more types of substrate. Because of these differences between augers and corers, the terms should not be used interchangeably.

Determining the provenience of Kennewick Man skeletal remains through sedimentological analyses

We present the results of a sedimentological study of a 9300 calendar yr old disarticulated skeleton known as Kennewick Man. Micromorphological, granulometric, mineralogical, and chemical analyses were performed on sediments from the skeleton and streambank adjacent to where the bones were found. Our results support earlier estimates that the skeleton eroded out from an 80 cm section of Columbia River flood deposits. Fine-textured sediments from the burial site attached to the bones indicate a low energy, fluvial depositional environment. Given the taphonomic evidence that Kennewick Man was rapidly buried, we believe that the stratigraphic and sedimentological evidence support the hypothesis that the body was interred by humans in the ground rather than being quickly buried by overbank flooding.

Vashon Island archaeology : a view from Burton Acres Shell Midden

ContributorsPrefaceAcknowledgments1. The Project: A Tribal Perspective--Judy Wright2. The Project: An Archaeological Perspective--Julie K. Stein3. Ethnographic Background--LLyn De Danaan4. Field and Laboratory Methods and Procedures--Mary Parr, Julie K. Stein, and Laura S. Phillips5. Stratigraphy and Dating--Julie K. Stein6. Historic Artifacts--MaryAnn Emery7. Lithics--Timothy Allen8. Bone and Antler Tools--Laura S. Phillips9. Faunal Analysis: Mammal and Bird Remains--Kristine Bovy10. Faunal Analysis: Fish Remains--Robert Kopperl and Virginia Butler11. Faunal Analysis: Shellfish Remains--Laura S. Phillips12. Botanical Analysis--Nancy A. Stenholm13. Conclusions--Julie K. Stein