Abstract
The Paleozoic minima of 87 Sr 86 Sr ratios and δ 34S values in seawater are observed in anhydrite layers of the Stassfurt (A-2) and Aller (A-4) cycles of evaporation of Late Permian age in Germany. These minima were probably caused by extremely low rates of continental runoff and bacterial sulfate reduction. Thereafter conditions changed suddenly, with a steeply increasing supply of radiogenic Sr and of nutrients into seawater. The latter induced a large growth in the production of organic material, in bacterial activity in sediments, and in the flow of isotopically heavy sulfur back into the oceans. This large change in the cycles of S and Sr (as well as of C and O) within the relatively short Zechstein period (2–5 Ma) reflects a considerable modification of the plate tectonic and environmental conditions shortly before the beginning of the Mesozoic era. The Ochoan deposition in the USA is probably of the same age as the Stassfurt-Leine evaporation in W Europe.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
