Dating the Lascaux Cave Gour Formation
Level 5 - mechanism / opinion, no new human data
Level 5 by design analogy (physical science / geochronological dating study with no clinical or human data)
OpenAlex W1916438908 · doi:10.1017/s0033822200034603
What was done
Researchers performed geochronological dating on the calcite flowstone (gour) formations of Lascaux Cave. They conducted 24 radiocarbon accelerator mass spectrometry (AMS) and 6 uranium-thorium (U-Th) analyses on gour calcite, 4 AMS 14C analyses on charcoals embedded in the calcite, and 4 AMS 14C analyses on organic matter extracted from the calcite. By combining charcoal and organic matter 14C ages with carbonate U-Th ages, they estimated the dead carbon proportion (dcp) and modeled calcite ages and growth rates using IntCal09 calibration data.
What was found
The gour calcite deposits grew between 9530 and 6635 yr cal BP when assuming a dead carbon proportion of 10.7 ± 1.8% (2 σ), or between 8518 and 5489 yr cal BP assuming a dead carbon proportion of 20.5 ± 1.9% (2 σ). This growth coincides with regional Holocene humid periods (the European Atlantic period and Mediterranean Sapropel 1). The gour deposits had ceased growing and remained inactive for thousands of years prior to the cave's re-entry in the 1940s.
Why it matters
This establishes the chronologic timeline for the water-ponding calcite structures in Lascaux Cave, demonstrating that they developed during the mid-Holocene rather than concurrently with Paleolithic painting ~18,000 years ago or immediately before modern rediscovery.
Limits
The findings rely on 38 total geochemical analyses from a single cave system. Absolute age boundaries vary by roughly 1,000 years depending on the estimated dead carbon proportion. The abstract notes that local geomorphological alterations at the cave entrance may have influenced gour development alongside broader climatic drivers.
Cited by
- supports The cave paintings of Lascaux date to approximately 20,000 years ago.