Chapter 4 Doing Fieldwork: Why Archaeologists Dig Square Holes

Outline  The Folsom Site and Humanity’s Antiquity in North America  Excavation: What Determines Preservation?  Principles of Archaeological Excavation  Precision Excavation  Sifting the Evidence  Cataloging the Finds  Site Formation Processes: How Good Sties Go Bad

Provenience  Once archaeologists excavate a site, nobody can ever dig it again, therefore compulsive field notes are necessary.  An artifact’s provenience is the most important thing about the artifact.  Provenience is essential to recording an artifact’s context – it’s relationship to other artifacts, features, and geological strata in a site.

Folsom Site  A politically important question was how long Native Americans had been here.  Evidence on animal habitation dated back to the Pleistocene – a geologic period from 2 million to 10,000 years ago, characterized by multiple periods of extensive glaciations.  Seeking ancient artifacts in unquestionable association with the bones of Pleistocene animals.

The Black Cowboy  Born into slavery, George McJunkin gained his freedom at the age of 14.  In 1890s he became the foreman at Crowfoot Ranch.  August 1908, he found a line that dangled across a now deep muddy gully and found ancient bison bones.  Spear points in situ between ribs of Bison antiquus  In situ – “in position”, the place where an artifact, ecofact, or feature was found during excavation or survey

Excavation: What Determines Preservation?  The exact procedures in any excavation depend on several factors, beginning with the kind of materials that have survived the passage of time.  Some sites preserve organic materials, including basketry, leather, and wood, in other sites only ceramics, stones, and bones survive.  Examples of various conditions under which organic remains are preserved:  The Duck Decoys of Lovelock Cave  The Houses of Ozette  The Iceman of the Alps

The Duck Decoys of Lovelock Cave  Lovelock Cave (Nevada) sits on a barren hillside north of the Carson Desert.  The dry and dusty interiors of Lovelock Cave was better suited for storing things that for shelter.  Harrington found a basket with 11 duck decoys made from tule reeds twisted to simulate the body and head of a duck  Radiocarbon dating indicates these were made 2,000 years ago.

The Houses of Ozette  Located on Washington’s Olympic Peninsula, Ozette was a major beachside village of the Makah people.  Part of the village lay along the bottom a steep hill and 300 y.a. a mudslide descended on the village burying five houses.  The thick layer of clay preserved entire houses with all their furnishings and gear.  In the 1970s R. Daugherty, with the help of contemporary Makah people, found and excavated 42,000 artifacts with remarkable preservation.

The Ice Man of the Alps  The Ötzi, the “Ice Man” died 5,300 years ago and his remarkably preserved body was found at 10,000 feet by two skiers in the Alps in  He froze shortly after his death and a small glacier sealed his body.  His frozen body preserved and scientists were able to extract a lot of information about him.

Preservation  Decomposition is carried out by microorganisms that require warmth, oxygen, and water to survive.  These different preservation conditions present the archaeologists with both opportunities and challenges.  Lovelock Cave lacked moisture  Wet deposits beneath the clay cap at Ozette were anaerobic (oxygenless)  Ice Man’s glacial environment lacked warmth  The excavation techniques must record an artifact’s context as precisely as possible.

Principles of Archaeological Excavation  The key to maintaining information about an artifact’s contex is its Provenience – an artifact’s location  Location is hierarchical to general geography and location.  Location is relative to a spatial system.  Test excavations – a small initial excavation to determine a site’s potential for answering a research question

Expanding the Test Excavation  Archaeologists first establish a datum, or zero point, which is a fixed reference used to keep control on an excavation; controls both the vertical and horizontal dimensions of provenience.  Archaeologists excavate within horizontal excavation units in natural levels and arbitrary levels.  Natural levels are the site’s strata which are more or less homogeneous, visually separable from other levels by a change in texture, color, rock, or organic content.  Archaeologists prefer to excavate in natural levels wherever possible.

Precision Excavation  Excavation has become an even more exact science.  More precise builder’s level and measuring rode are used.  Record horizontal provenience by measuring distances from two of a unit’s sidewalls and use total stations to record provenience.  The resulting information is critical to understanding how a site was formed and inferring what people did there.

Why Archaeologists Dig Square Holes 1.Pit sidewalls are kept straight and perpendicular to enable excavators to maintain horizontal control on the X and Y axes by measuring directly from the sidewalls. 2.If the excavator misses something, the sifting process can tie its provenience down to a particular level in a particular unit—a very small area of the site.

Sifting the Evidence:  Digging is just the beginning of excavation.  No matter how carefully you excavate, it is impossible to see, map, and recover everything of archaeological interest.  Sifters find things that hand excavation misses.

Water Screening  A sieving process in which deposit is placed in a screen and the matrix washed away with hoses.  Essential where artifacts are expected to be small and/or difficult to find without washing.  Matrix sorting - a hand sorting of processed bulk soil samples for minute artifacts and ecofacts.

Flotation  Using fluid suspension to recover burned plant remains and bone fragments.  Based on the principle: Dirt doesn’t float, but carbonized plant remains do.  Seemingly unimportant burnt seeds collected through flotation helped make the important discovery that Native Americans domesticated plants more than 4,000 years ago.

Principles of Archaeological Excavation  Record artifact context by recording provenience in detail.  Structure excavation methods to level of preservation.  Follow natural stratigraphy wherever possible; use arbitrary levels only where necessary.  Excavate in the smallest practical horizontal and vertical units to maintain provenience of artifacts not found in situ.  Utilize sieving, water screening, and sediment samples to recover small items.

Cataloging the Finds  Excavation is only about 15 percent of a project – most time is spent in the lab analyzing the remains.  Objects must be catalogued to ensure that an artifact’s original provenience, and consequently its context is never lost.

Site Formation Processes in the Systemic Context  Sites are complex and archaeologists must draw inferences about human behavior from sites by knowing how the site was formed over time.  The archaeological record is only the contemporary evidence left over from past behavior.  Systemic context – the living behavioral system in which artifacts were originally manufactured, used, and discarded  Archaeological contexts- once artifacts enter the ground they continue to be affect by human actuon but are also affected by natural processes.

Formation Processes in the Systemic Context  Formation processes – the ways in which human behaviors and natural actions operate to produce the archaeological record  Cultural Depositional Processes constitute the dominat factor in forming the archaeological record.  Discard – breaks or wears out and is discarded  Loss – inadvertently lost  Caching - stored  Ritual internment – burials, offerings

Formation Processes in the Systemic Context  Reclamation Processes- Human behaviors that result in artifacts’ moving from the archaeological context back to the systemic context, e.g. scavenging beams from an abandoned structure to use them in a new one.  Cultural Disturbance Processes- Human behaviors that modify artifacts in the archaeological context, e.g. digging pits, hearths, canals, and houses.  Reuse Processes- Human behaviors that recycle and reuse artifacts before the artifacts enter an archaeological context.

Formation Processes in the Archaeological Context  Once an object enters an archaeological context, a host of natural and cultural formation processes take place.  Natural processes determine not only whether organic material will be preserved, but also where objects will be found.  There is no simple correspondence between the distribution of artifacts in a site and human behavior.

Floralturbation  A natural formation process in which trees and other plants affect the distribution of artifacts within an archaeological site

Faunalturbation  A natural formation process in which animals, from large game to earthworms, affect the distribution of material within an archaeological site  Krotovina – a filled-in animal burrow

Cryoturbation  A natural formation process in which freeze/thaw activity in a soil selectively pushes larger artifacts to the surface of a site

Argilliturbation  A natural formation process in which wet/dry cycles push artifacts upward as the sediment swells and then moves them down as cracks form during dry cycles.

Graviturbation  A natural formation process in which artifacts are moved downslope through gravity, sometimes assisted by precipitation runoff.

Relevant Videos  FOLSOM POINT! Field-found in SW Wisconsin  In Focus: Ötzi, the “Ice Man”  Visit the Grand Canyon Archaeological Sites Hidden for Centuries oGKHpDvSwhttp:// oGKHpDvSw

Quick Quiz

1. The guiding rule in all excavation is to record context, and this means recording ________ of artifacts, features, and ecofacts.

Answer: provenience  The guiding rule in all excavation is to record context, and this means recording provenience of artifacts, features, and ecofacts.

2. Archaeologists prefer to excavate in arbitrary levels wherever possible. A. True B. False

Answer: B  Archaeologists prefer to excavate in natural levels wherever possible

3. No matter how carefully you excavate, it is impossible to see, map, and recover everything of archaeological interest; _____ finds things that excavation misses.

Answer: sifting  No matter how carefully you excavate, it is impossible to see, map, and recover everything of archaeological interest, sifting finds things that excavation misses.

4. Archaeology is a destructive science. A. True B. False

Answer: A  Sites can be excavated only once, so it is imperative we do things right the first time.