Structural Evolution at the Northeast North German Basin Margin: From Initial Triassic Salt Movement to Late Cretaceous‐Cenozoic Remobilization

• Published in: Tectonics (Washington, D.C.) Vol. 39; no. 7
• Main Authors: Ahlrichs, Niklas, Hübscher, Christian, Noack, Vera, Schnabel, Michael, Damm, Volkmar, Krawczyk, Charlotte M.
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 01-07-2020
• Subjects: Baltic Sea; Cenozoic; Compression; Cretaceous; Evolution; Fault zones; faults; Gravity; gravity gliding; Jurassic; Longline fishing; Mesozoic structural evolution; Ocean floor; salt tectonics; Salts; seismic imaging; Tectonics; Triassic
• ISSN: 0278-7407; 1944-9194
• DOI: 10.1029/2019TC005927

In this study, we investigate the regional tectonic impact on salt movement at the northeastern margin of the intracontinental North German Basin. We discuss the evolution of salt pillows in the Bay of Mecklenburg in the light of thick‐ and thin‐skinned tectonics, including gravity gliding, and differential loading using seismic imaging. Stratigraphic and structural interpretation of a 170 km long, multichannel seismic line, extending from the Bay of Mecklenburg to northeast of Rügen Island, incorporates well information of nearby onshore wells. This new high‐resolution seismic line completely images the stratigraphic and tectonic pattern of the subsurface, from the base of the Zechstein to the seafloor. Our analysis reveals that subsidence during Late Triassic to Early Cretaceous at the northeastern basin margin was associated with transtensional dextral strike slip movement within the Trans‐European Suture Zone. We reinterpret the Werre and Prerow Fault Zones west of Rügen Island as an inverted, thin‐skinned normal fault system associated with the formation of the Western Pomeranian Fault System. Salt movement in the Bay of Mecklenburg was initiated in the Late Triassic and lasted until the Early Jurassic. A second phase of salt pillow growth occurred during the Coniacian until Cenozoic and correlates with compression‐related regional basin inversion due to the onset of the Africa‐Iberia‐Europe convergence. Thin‐skinned extensional initialization of salt pillow growth and compressional salt remobilization explains salt pillow evolution in the Bay of Mecklenburg. Additionally, we discuss an impact of gravity gliding on salt pillow evolution induced by basin margin tilt.
Key Points
A regional high‐resolution seismic profile continuously images the SW Baltic Sea subsurface from the Zechstein salt base to the seafloor
Late Triassic salt movement and Late Cretaceous‐Cenozoic remobilization correlate with regional tectonics at the North German Basin margin
The tectonic evolution of salt pillows is discussed in terms of thin‐skinned extensional/compressional deformation and gravity gliding