Dating stone monuments presents a particular challenge because stone itself cannot be radiocarbon dated. Instead, archaeologists rely on associated organic material — charcoal from construction fires, bone fragments placed within chambers, or pollen trapped in buried soils beneath the stones. Radiocarbon dating measures the decay of carbon-14 in organic remains and, when calibrated against tree-ring sequences, can provide dates accurate to within a few decades.
Beyond radiocarbon, optically stimulated luminescence (OSL) dates the last time mineral grains in soil were exposed to sunlight, useful for establishing when a stone socket was dug. Archaeoastronomy offers another line of evidence: if a monument aligns precisely with a solstice sunrise, its builders must have observed and recorded that alignment, connecting the structure to a particular astronomical epoch.
These methods are complementary rather than competing. A single site might yield radiocarbon dates from charcoal, OSL dates from its stone holes, and archaeoastronomical evidence from its orientation. Taken together, they build a picture of when a monument was built, how long it was used, and whether it was modified over centuries — a reminder that these places were not frozen in time but evolved alongside the communities that tended them.