Two fundamental approaches to dating archaeological materials
Relative dating: establishes sequence (older/younger) without exact dates — stratigraphy, typology, seriation. Absolute dating: gives actual calendar dates — radiocarbon (C-14), potassium-argon (K-Ar), dendrochronology, thermoluminescence. Most sites use both in combination: relative methods for context, absolute for anchor dates.
Establish age as before/after without an absolute number
Stratigraphy: law of superposition — lower layers are older unless overturned. Typology: classify artifacts by style to establish sequences. Seriation: order artifacts by style changes over time. Fluorine dating: bones in same deposit absorb fluorine at same rate — confirms contemporaneity.
Radiocarbon Dating
Carbon-14: half-life ~5,730 years, reliable to ~50,000 years. Organic material only.
Radiocarbon Dating
The most widely used absolute dating method for organic material
Living organisms absorb C-14 from atmosphere. After death, C-14 decays at known rate. Measure remaining C-14 → calculate age. AMS (accelerator mass spectrometry) allows dating tiny samples. Works on bone, wood, charcoal, shell, seeds. Limit ~50,000 years. Calibration curves correct for atmospheric C-14 fluctuations.
K-Ar Dating
Potassium-Argon (K-Ar): half-life 1.3 billion years — dates volcanic rock layers near fossils
Potassium-Argon Dating
For ancient hominin sites — dates the volcanic rock above and below fossils
K-40 decays to Ar-40. When volcanic rock forms, argon escapes — clock resets to zero. Date the volcanic layer → constrain the fossil age between layers. Used at Olduvai Gorge (Homo habilis finds) and Laetoli (Australopithecus footprints). Ar-Ar dating is a refined version — more precise for small samples.
Taphonomy
Taphonomy: processes that modify bones and artifacts after death and deposition
Taphonomy
Understanding how the archaeological record forms — and gets distorted
Taphonomy studies: weathering, carnivore gnawing, water transport, bioturbation (burrowing animals), root etching, trampling, chemical dissolution. Essential for interpreting bone assemblages — distinguishes human butchery marks from carnivore tooth marks. Actualistic studies: observe modern bone decay to model ancient processes.
Provenience and Context
Provenience: exact 3D location of an artifact. Context: association with other objects. Looting destroys both.
Provenience and Context
An artifact's location is as scientifically important as the artifact itself
Provenience = precise coordinates (x, y, z) of a find. Primary context: undisturbed original position. Secondary context: object moved after deposition. Looted artifacts lose provenience permanently — scientific value destroyed. Field recording: total stations, GIS, photogrammetry now standard. A pottery sherd in situ tells more than a gold object without context.
Lithic Analysis
Lithic analysis: study of stone tools. Knapping = controlled fracture. Conchoidal fracture = predictable flaking.
Stone Tool Analysis
Reading the story of human technology from flaked stone
LiDAR (Light Detection and Ranging): laser pulses penetrate forest canopy → reveal hidden structures. Discovered Caracol Maya city, Angkor Wat complexity, Amazonian earthworks. GPR (ground-penetrating radar): bounces radar off subsurface features. Magnetometry: detects burned features and pits by magnetic anomalies. Aerial photography: crop marks show buried ditches and structures. Satellite imagery: large-scale survey.
The Neolithic Revolution
Neolithic Revolution: ~10,000 BCE — farming replaces foraging. "The most important change in human history."
Agricultural Origins
The shift to farming transformed human society in every possible way
Independent origins: Fertile Crescent (~10,000 BCE — wheat, barley, sheep), China (~8,000 BCE — rice, millet), Mesoamerica (~7,000 BCE — maize, squash), New Guinea (taro). Consequences: sedentism, surplus, population growth, social stratification, states, cities — but also: infectious disease increase, nutritional decline, warfare. The Çatalhöyük site (Turkey) documents early agricultural community life.
Two major theoretical schools that changed how archaeologists interpret the past
Processual (New Archaeology, 1960s): Binford — culture process, ecological adaptation, scientific method, hypothesis testing. Cultural systems, not just culture history. Post-processual (1980s): Hodder — meaning, symbolism, agency, gender, power. Critique: past people had intentions we can access. Modern archaeology: pluralist — combines scientific rigor with interpretive nuance.