No effect of thermal maturity on the Mo, U, Cd, and Zn isotope compositions of Lower Jurassic organic-rich sediments

Abstract The isotope ratios of redox-sensitive metals in organic-rich rocks are critical tools for quantifying the timing and severity deoxygenation nutrient cycling Earth's past. resilience isotopic data to thermal alteration host sediments over millions years burial is, however, largely unknown. We present molybdenum, uranium, cadmium, zinc stable-isotope from two stratigraphic successions same Lower Jurassic Posidonienschiefer unit Saxony Basin northern Germany that were affected by different histories. show maturity had no effect on compositions these elements but does appear have increased their concentrations rock. corroborate results laboratory-based maturation studies provide constraints Mo, U, Cd, Zn ca. 182 Ma seawater Basin.