The Mesozoic–Cenozoic structural framework of the Bay of Kiel area, western Baltic Sea

Abstract

A dense grid of multichannel high-resolution seismic sections from the Bay of Kiel in the western Baltic Sea has been interpreted in order to reveal the Mesozoic and Cenozoic geological evolution of the northern part of the North German Basin. The overall geological evolution of the study area can be separated into four distinct periods. During the Triassic and the Early Jurassic, E-W extension and the deposition of clastic sediments initiated the movement of the underlying Zechstein evaporites. The deposition ceased during the Middle Jurassic, when the entire area was uplifted as a result of the Mid North Sea Doming. The uplift resulted in a pronounced erosion of Upper Triassic and Lower Jurassic strata. This event is marked by a clear angular unconformity on all the seismic sections. The region remained an area of non-deposition until the end of the Early Cretaceous, when the sedimentation resumed in the area. Throughout the Late Cretaceous the sedimentation took place under tectonic quiescence. Reactivated salt movement is observed at the Cretaceous Cenozoic transition as a result of the change from an extensional to compressional regional stress field. The vertical salt movement influenced the Cenozoic sedimentation and resulted in thinskinned faulting.

High-resolution seismic analysis of the coastal Mecklenburg Bay (North German Basin): the pre-Alpine evolution

“…We assume that this fault reaches the seafloor. Bak-Hansen et al (2005) observed such faults in this region affecting the seafloor using higher frequency seismic data and smaller shot-receiver separations. In general, the study area lies between the Glückstadt Graben and the Vorpommern Fault system and is relatively unaffected by brittle faulting.…”

“…The distribution of the Cenozoic sediments shows an overall thickening trend towards the center of the basin in the south to southwest (Bak-Hansen et al 2005). On top of the Fehmarn Pillow, the Cenozoic succession is actually absent, pointing to reactivated vertical salt movement observed towards the end of the Late Cretaceous that must have continued throughout the Cenozoic.…”

“…After this major extensional phase the basin experienced a [100 ma interval of only minor tectonic events, which may be influenced by wrenching along the major faults, and may therefore record very sensitively sea-level changes (e.g., the Late Triassic Keuper). The Middle Jurassic to Early Cretaceous uplift period is marked by significant erosion removing parts of the Lower Jurassic and Upper Triassic successions within the Mecklenburg Bay and the Bay of Kiel area (Bak-Hansen et al 2005). The major, basin wide unconformity can be correlated with the rise of the Central North Sea Dome due to plutonic activity (Ziegler 1990;Underhill and Partington 1993).…”

“…The uplifted area was centered upon what later formed the North Sea rift triple junction (Underhill and Partington 1993), as a result of the rising plume. This explains the higher degree of erosion in the western direction in the Bay of Kiel towards the center of the dome (Bak-Hansen et al 2005). The adjacent Northeast German Basin is usually thought to be an area of non-deposition during the Middle and Upper Jurassic and the Lower Cretaceous (Kossow et al 2000;Kossow and Krawczyk 2002;Scheck et al 2003b), including the Ringkøbing-Fyn High to the north (Ziegler 1990).…”

Structure and evolution of the Northeastern German Basin and its transition onto the Baltic Shield

“…During these research cruises, a dense grid of high-resolution multichannel seismic data was acquired. The first outcome of this effort was the description of the post-Permian evolution of the Bay of Kiel (Hansen et al, 2005). Seismic interpretation allowed the reconstruction of the impact of the main tectonic phases, i.e.…”