Archaeologists use various methods and techniques to uncover and interpret the past. From excavation to survey, stratigraphy to artifact analysis, these tools help piece together human history. Understanding these methods is crucial for grasping how we learn about ancient societies.

These techniques reveal hidden clues about past cultures, from buried cities to tiny artifacts. By carefully uncovering and analyzing these remnants, archaeologists reconstruct ancient ways of life, shedding light on human evolution and cultural development throughout prehistory.

Archaeological Excavation Process

Principles and Techniques

• Archaeological excavation is a systematic process of uncovering and recording archaeological sites, features, and artifacts in their original context
• The main principles of archaeological excavation include:
  • Preservation of the site's stratigraphy and context ensures that the relationships between artifacts and features are maintained
  • Thorough documentation of all findings through notes, photographs, and drawings creates a detailed record for future research and interpretation
  • Careful removal and recording of artifacts and features allows for the reconstruction of past human activities and behaviors
  • Minimal disturbance to the site ensures that future research potential is not compromised
• The excavation process typically involves:
  • Site preparation, which includes clearing vegetation and establishing a reference grid
  • Grid layout, which divides the site into manageable units for systematic excavation
  • Surface survey, which identifies and records visible artifacts and features
  • Systematic removal of soil layers (spits) or following natural stratigraphy to uncover and document archaeological remains

Tools and Methods

• Archaeologists use various tools during excavation to carefully uncover and recover artifacts and features, such as:
  • Trowels for precise removal of soil and exposing artifacts and features
  • Brushes for cleaning and revealing delicate artifacts and surfaces
  • Shovels for removing larger amounts of soil
  • Sieves for screening excavated soil to recover small artifacts and ecofacts (seeds, bones)
• Proper excavation techniques, such as maintaining straight walls and flat floors, ensure that the maximum amount of information is retrieved from the site while minimizing damage to the archaeological record
• Other methods used during excavation include:
  • Flotation, which recovers small organic remains (seeds, charcoal) by agitating soil samples in water
  • Soil sampling for various analyses (pollen, phytoliths, chemical residues)
  • In-situ conservation of fragile artifacts and features (waterlogged wood, painted plaster)

Methods of Archaeological Survey

Non-invasive Techniques

• Archaeological survey is the process of identifying, recording, and interpreting archaeological sites and landscapes without excavation
• Pedestrian survey involves systematically walking over an area to identify surface artifacts, features, and sites (lithic scatters, pottery sherds, structural remains)
• Aerial photography and satellite imagery can reveal archaeological features such as:
  • Earthworks (mounds, ditches, roads)
  • Buildings and structural remains
  • Landscape modifications (terraces, irrigation systems) that may not be visible from the ground
• LiDAR (Light Detection and Ranging) is a remote sensing method that uses laser pulses to create high-resolution, three-dimensional maps of the landscape, revealing archaeological features obscured by vegetation (Maya ruins in the Guatemalan jungle)

Geophysical Prospection Methods

• Geophysical prospection methods allow archaeologists to detect subsurface features without excavation
• Magnetometry detects magnetic anomalies in the soil caused by human activities, such as:
  • Hearths or kilns that have been subjected to high temperatures
  • Iron objects or features containing magnetic minerals
• Ground-penetrating radar (GPR) uses radar pulses to create a profile of subsurface features and layers, such as:
  • Buried walls, foundations, or tombs
  • Soil disturbances or fill episodes
• Electrical resistivity measures the electrical resistance of the soil to identify buried features, such as:
  • Stone walls or foundations that have higher resistance than surrounding soil
  • Ditches or pits that have lower resistance due to higher moisture content
• These methods are often used in combination to provide a comprehensive understanding of the subsurface archaeological record (Stonehenge Hidden Landscapes Project)

Stratigraphy in Archaeological Interpretation

Principles and Concepts

• Stratigraphy is the study of layering in archaeological sites, which can provide crucial information about the relative age of artifacts and features
• The law of superposition states that, in an undisturbed sequence of layers, the oldest layers are at the bottom, and the youngest layers are at the top
• By understanding the stratigraphy of a site, archaeologists can:
  • Establish a relative chronology of events and reconstruct the site's formation processes
  • Determine the association between artifacts, features, and structures, providing insights into the activities and behaviors of past societies
• Stratigraphy can also reveal evidence of natural events, such as floods (alluvial deposits) or volcanic eruptions (tephra layers), that may have impacted human activities at the site

Recording and Analysis Methods

• Archaeologists use various methods to record stratigraphy, including:
  • Profile drawings, which depict the vertical sequence of layers along a wall or trench
  • Photographs, which provide a visual record of the stratigraphy and can be used for photogrammetry
  • The Harris Matrix, a diagram that represents the temporal relationships between stratigraphic units
• Stratigraphic units are defined based on their physical characteristics (color, texture, composition) and the interfaces between them (sharp, gradual, erosional)
• Artifacts and samples (charcoal, bone) recovered from each stratigraphic unit are used to date the layers and reconstruct past human activities
• Micromorphology, the microscopic analysis of thin sections from soil and sediment samples, can provide detailed information about site formation processes and human-environment interactions (Neolithic settlement of Çatalhöyük, Turkey)

Artifact Analysis for Past Societies

Classification and Interpretation

• Artifact analysis is the study of objects made, modified, or used by humans to gain insights into past societies' technological, economic, social, and cultural aspects
• Typology is the classification of artifacts based on their physical attributes, such as:
  • Shape and size (projectile point types)
  • Material (ceramic fabrics)
  • Decoration (painted motifs)
• Typologies can help establish chronologies and identify cultural traditions (Roman pottery typology)
• Functional analysis examines the use-wear patterns and residues on artifacts to determine their function and the activities they were associated with (microwear analysis of stone tools)

Scientific Techniques

• Technological analysis studies the manufacturing process of artifacts, including:
  • Raw material selection (obsidian sourcing)
  • Production techniques (pottery forming methods)
  • Skill level (apprenticeship in metalworking)
• Spatial analysis examines the distribution of artifacts within a site or across a landscape to identify:
  • Activity areas (lithic reduction zones)
  • Social organization (elite vs. commoner residences)
  • Trade networks (exotic materials)
• Archaeologists use various scientific techniques to analyze artifacts, such as:
  • Microscopy to examine the microstructure and composition of materials (petrography of ceramics)
  • Chemical analysis to identify the composition of artifacts and trace their origin (X-ray fluorescence of obsidian)
  • Residue analysis to detect organic remains, such as food or plant material, on artifact surfaces (starch grain analysis on grinding stones)
• By combining multiple lines of evidence from artifact analysis, archaeologists can reconstruct various aspects of past societies, including:
  • Subsistence strategies (faunal remains indicating hunting practices)
  • Social organization (architectural remains reflecting household structure)
  • Trade and exchange (imported goods and raw materials)
  • Ideology and symbolism (iconography on decorated artifacts)