The basement rock underneath Payún Matrú is formed by Mesoproterozoic (1,600-1,000 million years ago) to Triassic rocks of the San Rafael Block, Mesozoic (251.902 ± 0.024 to 66 million years ago) to Paleogene sediments of the Neuquén Basin and Miocene lava flows such as the Tertiary Patagonian basalts. The Andean orogeny during the Miocene has folded and deformed the basement, creating basins and uplifted basement blocks, and the Malargüe fold and thrust belt underlies part of the volcanic field. Oil has been drilled close to the volcanic field from sediments of Mesozoic age.