The dating technique which was used to establish the age of the volcanic ash at the Laetoli site is: potassium-argon (K/A) dating.
Absolute dating can be defined as a radioactive process that is typically used to accurately determine the age of a rock, volcanic ash or fossil, by measuring the decay of the isotopes that is associated with the rock or within the fossils.
Thus, scientists can accurately determine the age of a volcanic ash, rock or fossil by measuring its isotope concentration such as through the use of potassium-argon (K/A) dating.
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