Formation Processes in Archaeology
Archaeological Formation Processes and Taphonomy
Introduction to the Archaeological Record
The archaeological record constitutes the global sum total of all archaeological remains, including:
Artifacts (objects made or modified by humans)
Ecofacts (natural remains associated with human activity, e.g., seeds, animal bones)
Features (non-portable constructions or alterations by humans, e.g., hearths, postholes)
Architectural remains (structures, buildings)
Crucially, this sum total PLUS the various formation processes that have impacted these remains up to the present day define the archaeological record.
Taphonomy: The Study of Burial
Definition: Taphonomy is the specialized study of how and why something has come to be buried.
It investigates the processes that affect organic and inorganic remains from the time of death or deposition until the time of discovery by archaeologists.
Importance of Taphonomy: Understanding taphonomic processes is paramount because they directly influence what survives, how it survives, and its context within the archaeological record.
Example: Pompeii
Pompeii serves as a classic illustration of rapid and exceptional taphonomic preservation.
The city was buried by volcanic ash and pumice from the eruption of Mount Vesuvius in 79 \text{ AD}.
This rapid burial encapsulated structures, artifacts, and even human and animal forms, preserving them in remarkable detail due to the unique conditions of ash fall.
Cultural vs. Non-Cultural (Natural) Formation Processes
Formation processes are broadly categorized into those driven by human activity (cultural) and those driven by natural forces (non-cultural or natural).
Cultural Formation Processes
These are processes involving human behavior that introduce, modify, or remove items from the archaeological record.
Examples from archaeological site plans (e.g., Galaz, Old Town, Harris sites, Pithouse period structures along the Mimbres River) illustrate human activities over time, such as:
Acquisition of Raw Materials: Sourcing stone, clay, wood.
Manufacture and Use: Creation and utilization of tools, pottery, structures.
Discard and Burial: Deliberate or accidental disposal of items, leading to their entry into the archaeological record.
Reclamation and Modification: Humans reusing, recycling, or altering previously deposited materials or structures.
Intentional Disposal: Burials, caches, offerings.
Site Abandonment: How sites are left and subsequently become part of the archaeological landscape.
Natural Formation Processes
These are non-human agents that affect the archaeological record after deposition.
They can include, but are not limited to:
Sedimentation: The deposition of soils and sediments, burying objects (e.g., increasing depth in geological layers).
Erosion: The removal of archaeological materials by wind, water, or ice.
Bioturbation: Disturbance by living organisms, such as burrowing animals (rodents, insects) or plants (root growth), which can move artifacts vertically or horizontally.
Cryoturbation: Disturbance by freeze-thaw cycles in permafrost environments.
Pedoturbation: Soil formation processes.
Volcanic Activity: Like Pompeii, volcanic eruptions can bury and preserve or destroy sites.
These processes significantly alter the context and integrity of archaeological remains.
Preservation of Materials
Organics vs. Inorganics
The likelihood of an artifact or ecofact preserving depends heavily on its material composition.
Inorganic materials (e.g., stone tools, ceramic pottery, metals) generally preserve very well over long periods, especially in stable environments.
Organic materials (e.g., wood, textiles, bone, leather, feathers, uncharred plant remains) are much more fragile and typically rot or decompose quickly under normal conditions.
For example, feather cords made by Ancestral Pueblo peoples are rarely preserved, yet in specific contexts, their vibrant colors can be seen to have endured, offering insights into past aesthetics and ceremonial practices.