Sedimentary facies and paleontology of the Ottnangian Upper Marine Molasse and Upper Brackish Water Molasse of eastern Bavaria: A field trip guide

As a chronostratigraphic stage of the Paratethys realm, the Ottnangian comprises a single third order sequence and is correlated with the middle Burdigalian (Bur3). In the North Alpine Molasse Basin, the Ottnangian encompasses the most extensive transgression of the Paratethys Sea as well as its final retreat and replacement by brackish water ecosystems. The respective sediments of the Upper Marine Molasse and Upper Brackish Water Molasse are generally widely distributed in the eastern part of Bavaria (SE Germany). This field guide focuses on the development of the sedimentary facies and fossil biota of the Ottnangian strata in the Ortenburg-Passau and Simbach am Inn regions. The entire marine succession, which comprises the Untersimbach Beds, Neuhofen Beds, and “Glaukonitsande und Blättermergel,” as well as the nearshore equivalents of these facies can be observed in the presented outcrops. Two of the outcrops exemplify the lower Ottnangian transgression on a granitic basement. Moreover, the lower portion of the Upper Brackish Water Molasse is featured with two outcrops, which show the typical sedimentary succession of these strata. Both sections include the so-called “Schillhorizont,” a famous coquina and marker bed, which is almost exclusively composed of millions of shells of a single brackish water bivalve species.