Thorianite (ThO 2 ) was found in the phlogopite -bearing spinel -garnet peridotite (Plešovice peridotite) occurring as decimeter -size lenticular body in the Gföhl granulite that forms the metamorphic core of the Variscan orogenic belt. Thorianite occurs as a member of multiphase solid inclusions, consisting of phlogopite + carbonates + apatite + graphite + rutile + monazite + thorianite, in chromian spinel. U -Th -Pb ages of the thorianite give a good concentration at 333.8 ± 4.5 Ma, which overlaps the U -Pb ages of zircon extracted from the host Gföhl granulite, probably reflecting the Variscan high -pressure high -temperature metamorphism during the continentcontinent collision.

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