Chronometric dating, also known as absolute dating, refers to methods that provide a specific calendar age or a range of dates for archaeological, geological, or paleontological materials. Unlike relative dating, which only establishes a sequence of events, chronometric methods yield quantifiable ages based on measurable physical or chemical processes that occur at a known, constant rate.

Key chronometric dating techniques include:

• Radiocarbon Dating (C-14): Measures the decay of radioactive carbon-14 in organic materials (wood, charcoal, bone, textiles) up to approximately 50,000 years old. It's widely used in archaeology.
• Potassium-Argon (K-Ar) / Argon-Argon (Ar-Ar) Dating: Measures the decay of Potassium-40 to Argon-40 in volcanic rocks, suitable for very old samples, often millions of years, crucial for dating early hominin sites.
• Uranium-Series Dating: Based on the decay of uranium isotopes in calcium carbonates (e.g., stalagmites, teeth, corals), useful for dating materials from about 10,000 to 500,000 years ago.
• Thermoluminescence (TL) / Optically Stimulated Luminescence (OSL): Measures accumulated radiation in crystalline materials (pottery, burnt flint, sediments) since they were last exposed to heat or light, dating objects up to several hundred thousand years.
• Dendrochronology (Tree-Ring Dating): Provides highly precise dates by matching and counting annual growth rings in trees, applicable to wooden artifacts and structures.

Chronometric dating is indispensable for constructing accurate timelines of human prehistory, understanding cultural sequences, and correlating archaeological findings with environmental and geological events.