The Carbon and Oxygen Isotope Composition of Secondary Carbonates in Volcanites of the pre-Jurassic Complex of the West Siberian Plate

Resumo

The carbon and oxygen isotope composition of secondary carbonates from acidic effusives in the top of the pre-Jurassic complex of the West Siberian plate (Tomsk Region) was studied. The siderite values of δ¹³С (VPDB) and δ¹⁸О (VSMOW) vary from –6.6 to –2.4‰ and from 7.8 to 12.3‰, while the calcite values vary from –8.9 to –8.4‰ and from 2.5 to 3.7‰, respectively. The light oxygen isotope composition indicates that the carbonates were from medium- and low-temperature hydrothermal solutions.