excess thorium-230
Quick Summary
Excess thorium-230 dating is a geochronological method used to determine the age of marine sediments. This technique relies on the radioactive decay of isotopes, specifically protactinium-231 and thorium-230. These isotopes have half-lives of 32,500 years and 80,000 years, respectively.12
The method is effective because protactinium and thorium share similar chemical properties, leading to their precipitation at comparable rates in marine environments. By analyzing the ratio of these two isotopes, scientists can date sediments up to 175,000 years old, even if sedimentation rates have varied over time. This method is a part of broader uranium-series disequilibrium dating techniques used to date geologically young materials.13
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