New advances in the stratigraphy and geochemistry of the German Turonian (Late Cretaceous) tephro- stratigraphic framework

The lowest of the five bentonites in the German Turonian tephrostratigraphic framework, T[C], can be correlated for the first time from the Rotplaner (red limestone) standard section in the Sohlde-Loges Quarry (Lower Saxony) to highly condensed, near-swell successions of the nearby Woltwiesche Quarry and the Hoppenstedt Quarry (Saxony-Anhalt). A second bentonite, T[C2], only recently recognised at Sohlde-Loges, is now identified at Woltwiesche and in the distal/expanded white limestone successions of the Salzgitter-Salder Quarry and the Floteberg road-cutting (both Lower Saxony). T[C2] can easily be located a short distance above a major lithofacies change (herein termed the Basal Upper Turonian Facies Turnover), making it an isochronous marker permitting correlation between condensed near-swell and expanded basinal sections. On this basis, a bentonite, previously identified as T[C] at Hoppenstedt must be re-assigned as T[C2].Examination of the major, trace, and rare-earth element (REE) data of all the five bentonites identified in Lower Saxony and Saxony-Anhalt shows that it is possible to discriminate between them to some extent. Bentonites TC[ ]and T[C2] are geochemically similar and separable from T[D], which is itself distinct from T[E] and T[F].