Chemo- and sequence stratigraphy of Toarcian to Aalenian sedimentary successions from southern Germany

Toarcian to Aalenian sedimentary deposits in southern Germany have been accumulated in a shallow-marine, epicontinental shelf environment. The according successions are dominated by marlstones, thick claystones and argillaceous siltstones, with increasing percentages of sandstones towards the top of the Aalenian. While the Toarcian, including the TOC-rich paper shales of the Toarcian Oceanic Anoxic Event (T-OAE), is characterized by distinct lithologies, resulting in a number of hiatuses, Aalenian sedi­ments are likely to represent a relatively complete stratigraphic record. Although the investigated sequences are located in a region that has been known for its famous Jurassic sequences for more than 150 years, the sedimentary evolution and paleoclimatic significance of these successions, remain largely unexplored on a basin-wide scale. Here we present a suite of high-resolution x-ray fluorescence (XRF) core scanning, stable organic carbon isotope and biostratigraphy data to identify Transgressive-Regressive cycles during the Late Toarcian to Aalenian. Results are based on four scientific drill cores of 200 - 250 m length, taken on a profile over a distance of about 300 km. Resulting trends in elemental Si/Al ratios, which are indicative for subtle grain-size variations, combined with sedimentological observations on ichnofacies and bedform development were used to reconstruct shoreline trajectories and establish a sequence stratigraphic framework. Our study mainly focus the thick and largely homogenous lower Aalenian Opalinuston Formation.