Site Formation Processes

Site formation processes explain how an archaeological site came into its current state. These processes bridge the gap between human activities in the past and the physical remains discovered by researchers. They are categorized into cultural processes and natural processes.

Cultural Formation Processes

Cultural processes are activities performed by human beings that create or modify the archaeological record.

C-transforms

C-transforms refer to the life cycle of artifacts and features. They include acquisition, manufacture, use, and discard.

• Acquisition: Humans gather raw materials from the landscape.
• Manufacture: Materials are modified into tools or other objects.
• Use: The artifact serves a functional or symbolic purpose.
• Discard: The object is abandoned or intentionally deposited in a midden or burial.

Reuse and Recycling

Archaeological sites often show evidence of secondary usage.

• Reuse: An object is used for a different purpose than its original intent, such as using a broken ceramic vessel as a scoop.
• Recycling: A broken tool is reworked into a smaller, functional tool, such as turning a shattered handaxe into a scraper.

Deliberate Deposition

Human actions include the intentional burial of objects for rituals or protection.

• Burials: The placement of human remains with grave goods.
• Caches: The storage of tools or valuables intended for future retrieval.
• Foundation deposits: Items placed within the structure of a building during construction.

Natural Formation Processes

Natural processes, or N-transforms, involve environmental events that move, bury, or destroy artifacts after their deposition.

Geomorphological Processes

Geological forces play a major role in site modification.

• Erosion: Wind and water remove soil and artifacts from a site, often destroying the stratigraphic context.
• Deposition: Sediments such as sand, silt, or volcanic ash bury a site, protecting it from surface disturbances.
• Bioturbation: Plants and animals alter the soil layers. Tree roots can push artifacts to different levels, and burrowing animals like rodents or earthworms cause vertical mixing of deposits.

Chemical Processes

Chemical conditions in the soil dictate the preservation of materials.

• Acidity: Highly acidic soils dissolve bone, shell, and other calcium-based materials.
• Waterlogging: Saturated, anaerobic environments prevent decay by excluding oxygen. This preserves organic materials like wood, leather, and textiles.
• Oxidation: Exposure to air causes metals to corrode and organic matter to decompose rapidly.

Physical Processes

Physical forces can shift artifact locations.

• Cryoturbation: The cycle of freezing and thawing in cold climates causes the soil to heave, moving artifacts vertically and horizontally.
• Solifluction: The slow downhill movement of water-saturated soil can displace entire archaeological layers.

Analytical Frameworks

Archaeologists use specific frameworks to untangle these processes.

Primary and Secondary Contexts

• Primary Context: The original location where an object was deposited and remained undisturbed. This provides the most accurate information about human behavior.
• Secondary Context: A location where artifacts have been moved from their original position by natural or human activity. These contexts provide limited information about the activity that created them.

Site Formation Matrix

Interpretation of the Archaeological Record

Understanding formation processes prevents the misinterpretation of natural events as cultural ones.

• Feature Identification: Digging a hole for a storage pit creates specific soil color changes that differ from natural animal burrows.
• Assemblage Analysis: Researchers must determine if a collection of tools was abandoned in place or swept into a refuse pit by water.
• Stratigraphic Integrity: By examining soil composition, archaeologists determine if a layer represents a single occupation event or a palimpsest of many events occurring over centuries.

Key Facts about Formation Processes

• The term palimpsest is used when multiple occupation events are compressed into a single stratigraphic layer, making it difficult to distinguish specific activities.
• The Pompeii Premise is a concept describing the mistaken belief that an archaeological site represents a perfect, frozen moment in time. Most sites are the result of long-term use and constant modification by both humans and nature.
• Middens are concentrated deposits of domestic waste, such as shells, bones, and charcoal. They are excellent sources for environmental reconstruction but require careful analysis to distinguish between domestic refuse and intentional ritual deposits.
• Refitting is a method used to assess site integrity. Archaeologists attempt to reassemble broken pottery or stone tool flakes found in different areas of a site. If the pieces connect, it proves that the artifacts have not been moved significantly by natural processes.
• Micro-refuse analysis involves sifting soil samples through fine meshes to recover tiny debris. This allows researchers to identify activity areas, such as locations where stone knapping occurred, even if the larger artifacts were removed or destroyed.
• The concept of site formation was popularized by Michael Schiffer, who emphasized the importance of distinguishing between artifacts in use and artifacts in the archaeological record.
• Waterlogged sites are rare but essential for understanding the past. Sites like the Ozette village in Washington, USA, were buried by a mudslide, which created a anaerobic seal that perfectly preserved wooden tools, basketry, and even food remains.

Soil micromorphology involves studying thin slices of soil under a microscope. This reveals microscopic evidence of trampling, floor construction, and waste management, which are often invisible to the naked eye.