Which dating method is based on the last heating event by measuring radiation absorbed since then?

• A. Radiocarbon dating
• B. Dendrochronology
• C. Potassium-argon dating
• D. Thermoluminescence

Answer: (D)

Thermoluminescence dating hinges on the fact that minerals in the sample continuously accumulate trapped charge from environmental radiation after they are last heated. That heating event resets the stored energy, so after cooling the clock starts again. Over time, environmental radiation replenishes these traps. When the material is heated again in the lab, the trapped energy is released as light—the brighter the glow, the more radiation dose has built up. By measuring this glow (the equivalent dose) and knowing the rate at which the sample accumulates dose each year, we can estimate how long it has been since the last heating event. This method is especially useful for fired ceramics and burnt rocks. Other dating methods rely on radioactive decay in organic material, tree-ring counts, or isotope decay in rocks, not on the heating-reset signal used here.