<?xml version="1.0" encoding="utf-8"?><metadata xmlns:dc="http://purl.org/dc/elements/1.1/"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dcterms="http://purl.org/dc/terms/"><dc:title xml:lang="en">uranium-thorium dating</dc:title><dc:identifier>http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31410439</dc:identifier><dc:language>en</dc:language><dc:publisher xml:lang="en">Getty Institute</dc:publisher><dcterms:created>2026-03-30 20:50:21</dcterms:created><dcterms:isPartOf xsi:type="dcterms:URI">http://AATesaurus.cultura.gencat.cat/aat/getty_en</dcterms:isPartOf><dcterms:isPartOf xml:lang="en">Tesaurus d&apos;Art i Arquitectura</dcterms:isPartOf><dc:format>text/html</dc:format> <dcterms:alternative xml:lang="en">U-Th dating</dcterms:alternative> <dcterms:alternative xml:lang="en">dating, uranium-thorium</dcterms:alternative> <dc:description xml:lang="en"><![CDATA[ Radiometric dating method which measures the age of igneous calcium carbonate materials. The technique calculates the degree to which radioactive thorium-230 isotopes within a sample have reestablished secular equilibrium with their parent uranium-234 isotopes. ]]></dc:description></metadata>