Deciphering the Cretaceous Lower Saxony Basin: Lithostratigraphic and geochemical insights from a 1,500-m composite record

The Lower Cretaceous sediments of the central Lower Saxony Basin (LSB) are primarily composed of thick, CaCO₃-poor mudstones and siltstones. These deposits exhibit a continuous increase in CaCO₃ content during the Albian–Cenomanian interval, culminating in chalky deposits in the upper Cenomanian. The sedimentary system is predominantly controlled by two contrasting processes: carbonate production and the input of fine-grained siliciclastics from the hinterland.

This study presents a 1,500-meter composite stratigraphic record spanning the late Berriasian to the middle Turonian, derived from 14 drill cores. All cores are located in the Hannover area, which served as the depocenter of the LSB during the Early to mid-Cretaceous. In addition to a published long-term carbon isotope stratigraphy (Bornemann et al., 2023), we generated high-resolution CaCO₃ and total organic carbon (TOC) data. Our objective was to evaluate whether the lithostratigraphic units can be clearly differentiated from adjacent units based on these parameters.

As a case study, we revisit the lithostratigraphic subdivision of the Albian – Cenomanian transition using CaCO₃ and TOC, but also X-ray fluorescence core scanning data from the Anderten 1 and 2 cores.

References:
Bornemann, A., Erbacher, J., Blumenberg, M., Voigt, S., 2023. A first high-resolution carbon isotope stratigraphy from the Boreal (NW Germany) for the Berriasian to Coniacian interval—implications for the timing of the Aptian–Albian boundary. Front. Earth Sci. 11, 1173319. https://doi.org/10.3389/feart.2023.1173319