Hypolimnetic oxygen conditions influence varve preservation and δ13C of sediment organic matter in Lake Tiefer See, NE Germany - Nadine Dräger; Birgit Plessen; Ulrike Kienel; Michał Słowiński; Arne Ramisch; Rik Tjallingii; Sylvia Pinkerneil; Achim Brauer (Journal of Paleolimnology, 2019)