Chemical and isotopic properties of kukersites from Iowa and Estonia

Kukersite samples from Estonia and Iowa were analyzed for elemental composition, functional group distribution, and carbon and hydrogen stable isotope ratios. The elemental and hydrogen isotope values, together with other analytical data, suggest a higher thermal maturity for the Iowa kukersite. The wide carbon isotopic range of 9.3‰ among kukersites, with unusually negative δ13C values reaching −33.2‰, indicates isotopically variable carbon sources for production of biomass, and thus major paleoceanographic differences between the environments supporting biosynthesis.