Bipolar percussion is a lithic reduction technique in stone tool production where a core is placed on an anvil and struck from above, causing flakes to detach from both ends simultaneously. It is a distinctive method used when raw material is small, tough, or difficult to work with using freehand percussion.

🌍 Definition

• Bipolar Percussion: A flaking technique in which a stone core is positioned on a hard surface (anvil) and struck with a hammerstone, producing flakes from both the point of impact and the opposite end.
• Resulting Morphology:
  • Flakes often show crushing or battering at both ends.
  • Cores exhibit opposing impact scars and splintering.
• Contrast:
  • Direct Percussion: Striking a core held in the hand or stabilized without an anvil.
  • Bipolar: Requires both hammer and anvil, producing distinctive fracture patterns.

🔑 Archaeological Contexts

• Raw Material Constraints:
  • Common when knappable stone is small (e.g., pebbles, nodules).
  • Efficient for maximizing usable flakes from limited resources.
• Global Use:
  • Found in Paleolithic contexts worldwide, including Africa, Europe, and the Americas.
• Diagnostic Features:
  • Opposing crushing at ends of flakes.
  • Splintered cores with bidirectional fracture scars.
• Functional Role:
  • Produced sharp flakes for cutting, scraping, or projectile point preforms.

📚 Importance in Anthropology

• Technological Insight: Shows adaptation to material constraints and efficiency in resource use.
• Cultural Identity: Presence of bipolar percussion indicates specific technological traditions or ecological adaptations.
• Comparative Value: Highlights differences between freehand flaking traditions and bipolar strategies.
• Material Culture Link: Bipolar percussion often associated with expedient toolkits and mobile hunter-gatherer groups.

In short: Bipolar percussion is a lithic technique where a core is struck on an anvil, producing flakes from both ends, especially useful for small or tough raw materials.