Sequence stratigraphic interpretation of the Toarcian succession in Northern Germany (including the Hainberg section) and Thuringia in comparison with 3rd order South-German and the 2nd order Boreal standard cycles. Sedimentary succession and ammonite biostratigraphic evidence according to Denckmann (1892), Ernst (1923–1924), Kumm (1941), Ernst (1970), Maul (1984), Brachmann (1991), Krause and Katzung (1999), and specimens from the BGR collection [https://gewis.bgr.de/, leg. K. Hoffmann, R. Jordan, K. Wiedenroth]. T-R cycles: 1 third order sequences Northern Germany (Zimmermann et al. 2015), 2 third order sequences Southern Germany (Röhl and Schmid-Röhl 2005; Arp et al. 2021); 3 second order sequences Boreal standard (de Graciansky et al. 1998; Jacquin et al. 1998).