GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2023-07-19
    Description: The geometry of sedimentary basins is normally described by the interpretation of seismic reflectors. In addition to that, rock properties of the sedimentary successions between these reflectors give further insight into the subsurface geology. Here, we present a model for the Bay of Mecklenburg, situated at the northeastern margin of the North German Basin. The model consists of eight layers; it covers seismic velocities of sediments from the Neogene down to the base of the Permian Zechstein. We use eight seismic profiles for model building and apply seismic migration velocity analysis in combination with pre-stack depth migration. The results are interval velocities down to a depth of 5000 m. A further aim of the study is to investigate the sensitivity of these indirectly deduced velocities in comparison to direct measurements within drill holes. The velocities from this study are in good agreement with earlier results from vertical seismic profiling at a nearby well. Cenozoic and Mesozoic strata within the Bay of Mecklenburg show clear depth-dependent velocity trends. A comparison of these trends with predicted compaction trends shows that burial anomalies within Lower Triassic units are significantly higher than in Upper Cretaceous units. This finding could be explained by a greater amount of erosion during Upper Jurassic/Lower Cretaceous times than during Cenozoic times. The Zechstein layer shows a decreasing interval velocity with increasing thickness. Our study demonstrates that seismic velocities deduced from surface-based measurements are of high value in areas with sparse drilling coverage.
    Description: Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) (4230)
    Description: https://www.geo-seas.eu/search/welcome.php?query=1678&query_code=%7b558D29F1-65F5-4441-8CAF-8E15926546E9%7d
    Keywords: ddc:551.1 ; Bay of Mecklenburg ; seismic profiling
    Language: English
    Type: doc-type:article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024-02-15
    Description: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The formation and structural evolution of complex intracontinental basins, like the North German Basin, mark fundamental earth processes. Understanding these is not only essential to basic research but also of socioeconomic importance because of the multitude of resources, potential hazards, and subsurface use capability in such basins. As part of the Central European Basin System, major subsidence and structural differentiation affected the Baltic sector of the North German Basin in Permian‐to‐Jurassic times. A dense network of high‐resolution 2D seismic data together with nearby wells allow the creation of regional maps with refined stratigraphic subdivision of unprecedented spatial resolution covering the bays of Kiel and Mecklenburg (Baltic Sea). Cross sections along the basin margin allow reconstruction of the structural evolution of the Zechstein salt and its overburden. At the northern basin margin, near the Kegnaes Diapir, thinning of the Buntsandstein and divergent reflectors indicate Early Triassic faulting and salt movement. In the Late Triassic, tectonic activity increased as expressed by the onset of salt movement in the north‐eastern Glückstadt Graben, major growth of the Kegnaes Diapir and faulting at the north‐eastern basin margin during deposition of the Keuper (Erfurt, Grabfeld, Stuttgart and Weser formations). At the north‐eastern basin margin, we interpret the accumulation of Keuper and Jurassic deposits as an infill of a local sub‐basin bordered by the Werre Fault Zone and Agricola Fault System. Between the Glückstadt Graben and the north‐eastern basin margin, the Eastholstein–Mecklenburg Block formed a more stable area, where salt movement first began during the latest Triassic. In the peripheral part of the basin, salt movement was triggered by thin‐skinned extension associated with thick‐skinned faulting within the axial parts of major graben systems. Indications for gravity gliding are absent. Reactive diapirism is restricted to the basin margin, where reduced overburden thickness and Late Triassic erosion allowed diapiric breakthrough.〈/p〉
    Description: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We investigate the complex evolution of the northern intracontinental North German Basin and elucidate the impact of regional tectonics on salt movement in Permian‐to‐Jurassic times. We describe the onset and characteristics of salt movement throughout the study area and explain observed isolated diapirism at the basin margin.〈boxed-text position="anchor" content-type="graphic" id="bre12760-blkfxd-0001" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:0950091X:media:bre12760:bre12760-toc-0001"〉 〈/graphic〉〈/boxed-text〉〈/p〉
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Keywords: ddc:551.8 ; North German Basin ; Baltic sector ; Triassic-Jurassic structural evolution ; salt tectonics ; seismic imaging
    Language: English
    Type: doc-type:article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2024-01-24
    Description: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The reactivation of faults and possible impact on barrier integrity marks a critical aspect for investigations on subsurface usage capabilities. Glacial isostatic adjustments, originating from repeated Quaternary glaciations of northern Europe, cause tectonic stresses on pre‐existing fault systems and structural elements of the North German and Norwegian–Danish basins. Notably, our current understanding of the dynamics and scales of glacially induced fault reactivation is rather limited. A high‐resolution 2D seismic data set recently acquired offshore northeastern Langeland Island allows the investigation of a fault and graben system termed the Langeland Fault System. Seismo‐stratigraphic interpretation of reflection seismic data in combination with diffraction imaging unravels the spatial character of the Langeland Fault System along an elevated basement block of the Ringkøbing–Fyn High. In combination with sediment echosounder data, the data set helps to visualize the continuation of deep‐rooted faults up to the sea floor. Initial Mesozoic faulting occurred during the Triassic. Late Cretaceous inversion reactivated a basement fault flanking the southern border of the elevated basement block of the Ringkøbing–Fyn High while inversion is absent in the Langeland Fault System. Here, normal faulting occurred in the Maastrichtian–Danian. We show that a glacial or postglacial fault reactivation occurred within the Langeland Fault System, as evident by the propagation of the faults from the deeper subsurface up to the sea floor, dissecting glacial and postglacial successions. Our findings suggest that the Langeland Fault System was reactivated over a length scale of a minimum of 8.5 km. We discuss the causes for this Quaternary fault reactivations in the context of glacially induced faulting and the present‐day stress field. The combination of imaging techniques with different penetration depths and vertical resolution used in this study is rarely realized in the hinterland. It can therefore be speculated that many more inherited, deep‐rooted faults were reactivated in Pleistocene glaciated regions.〈/p〉
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: https://doi.org/10.1594/PANGAEA.954017
    Keywords: ddc:551.8 ; Langeland Fault System ; Quaternary ; fault reactivation ; seismo-stratigraphic interpretation
    Language: English
    Type: doc-type:article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2024-04-10
    Description: Seismic data from the North Sea commonly show vertical acoustic blanking (VAB) often interpreted as fluid conduits with implications for Quaternary development. The robustness of this interpretation has long been controversial as the infill of tunnel valleys can also cause vertical blanking. Using 2D and 3D seismic data and sediment echosounder data from the German North Sea, we investigate VAB to determine a geological or imaging origin of these anomalies. We detected multiple VAB occurrences throughout the North Sea. 3D data from the Ducks Beak (‘Entenschnabel’) reveal a correlation of VAB with bright spots in incised channels directly below the seafloor. Large source–receiver distances allow imaging the subsurface below the channel without signal penetrating through it (undershooting). This method removes the blanking. Energy absorption by shallow biogenic gas trapped within the channels explains the observed VAB. Hence, the blanking represents an imaging artifact, highlighting the need for careful seismic processing with sufficient offset before interpreting such anomalies as fluid pathways. The channels belong to a postglacial channel system related to the now submerged lowlands of Doggerland. This work demonstrates the usability of mapping VAB to detect shallow features for paleo‐landscape reconstruction and identification of shallow gas for hazard assessments, for example.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Format: text
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2024-06-26
    Description: In the Late Cretaceous to Cenozoic, multiple inversion events affected Central Europe's intracontinental sedimentary basins. We investigate the impact of these inversion events on Zechstein salt structures formed prior to inversion based on seismic data located in the Baltic sector of the North German Basin. The study area covers the eastern Glückstadt Graben and the Bays of Kiel and Mecklenburg. We link stratigraphic interpretation to previous studies and nearby wells and present key seismic depth sections and thickness maps at a new level of detail. Prestack depth migrated seismic profiles are part of the BalTec dataset acquired during cruise MSM52 in march 2016 in the Baltic Sea. The seismic equipment consisted of an eight GI‐Gun cluster (45/105 in³) allowing for deep signal penetration with a relatively wide frequency bandwidth with a dominant frequency of 80 Hz. The streamer had an active cable length of 2,700 m with a minimum offset of 33 m. Seismic processing included τ‐p domain prestack predictive deconvolution, surface‐related multiple attenuation (SRME) to attenuate multiples, frequency filtering, amplitude recovery, noise reduction, and prestack depth migration. The time migrated seismic profile was acquired during a student marine excursion of the University of Hamburg in 2019, cruise AL526. A Mini-GI gun (true GI-mode with 15 in³ generator and 30 in³ injector volume) and a 48 channel streamer with 4m group spacing was used. Seismic data processing was analog to the depth sections, except for migration. Here, a poststack kirchhoff time migration was applied. For mapping, we used all available lines in the study and created time-structure maps by minimum curvature spline interpolation with a grid cell size of 300x300 m. By subtracting the top and bottom horizons, we created isochron maps (vertical thickness in two-way time) for the Zechstein, Cenomanian-Turonian, Coniacian-Santonian, Campanian, Maastrichtian-Danian, upper Paleocene, Eocene-Miocene units. We converted the time-isochron maps to vertical thickness in meter by using constant velocities derived from averaging the results of the refraction travel-time tomography.
    Keywords: AL526; AL526_4; AL526_9-1; AL526_9-2; Alkor (1990); Baltic Sea; Binary Object; Binary Object (File Size); Binary Object (Media Type); Der marine Sektor des Norddeutschen Beckens und der Tornquist Zone: Strukturelle Entwicklung und Fluidmigration; Maria S. Merian; MSM52; MSM52_124-1; MSM52_137-1; North German Basin; SEIS; Seismic; seismic data; Seismic reflection profile; SEISREFL; StrucFlow; thickness maps; time-structure maps
    Type: Dataset
    Format: text/tab-separated-values, 7 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2024-06-26
    Description: The understanding of the dynamics and scales of glacially induced faulting greatly benefits from an analyis using multiple geophysical datasets. By using a combination of high-resolution 2D seismic reflection data in combination with diffraction imaging, sediment echosounder data and shallow wells, we investigate a fault and graben system offshore Langeland Island in the Baltic Sea, which we term the Langeland Fault System. This approach allows to unravel the spatial character of the Langeland Fault System along an elevated basement block of the Ringkoebing-Fyn High. Our analysis shows the continuation of deep-rooted faults up to the seafloor. Imaging the shallowmost strata reveals Quaternary fault reactivation during glacial or postglacial times. This combination of imaging techniques is rarley realized in the onshore hinterland, thus, representing a unique analysis of Quaternary fault reactivation by combining onshore and offshore data and methods. Seismic data was acquired in September 2020 during a student field exercise cruise onboard R/V Alkor. The survey was organized by the University of Hamburg (Cruise AL545). Seismic data acquisition was carried out using a Mini-GI gun (true GI-mode with a 15 in³ generator and 30 in³ injector volume) and a 48-channel streamer with 4 m group spacing. The data have a dominant frequency of 250 Hz. Signal penetration is up to 1 s two-way travel time (TWT). The seismic processing routine included frequency filtering, amplitude recovery, noise reduction, surface-related multiple attenuation (SRME), Kirchhoff time migration. Innomars SES 2000 parametric sub-bottom profiler, which is hull-mounted on R/V Alkor, was used for the acquistion of the sediment echosounder data (Primary frequencies of about 100 kHz, secondary parametric frequency: 8 kHz). The diffraction imaging is based on separating the dominant reflected wavefield through a coherent summation scheme guided by a dip-based wavefront filter. In a next step, the reflection-only data is subtracted from the input data. The diffraction-only data is then focused using FD migration. By calculating the squared envelope of the focused diffractions, the diffraction energy stacks are obtained. The mapping procedure includes gridding using all available profiles in order to create time-structure maps by minimum curvature spline interpolation. Isochron maps (vertical thickness in two-way time) for the Triassic to Quaternary units were calculated by subtracting the top and bottom horizons of the specific units.
    Keywords: AL545; AL545_5-2_26; AL545_5-2_40; AL545_5-2_41; Alkor (1990); Baltic Sea; Binary Object; Binary Object (File Size); Diffraction imaging; Event label; File content; Glacially induced faults; GPF 19-1_80; Langeland; P26; P40; P41; reflection seismics; sediment echosounder; Seismic; Seismic reflection profile; SEISREFL; thickness maps; time-structure maps
    Type: Dataset
    Format: text/tab-separated-values, 24 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2021-07-04
    Description: 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.
    Description: 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.
    Description: Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) http://dx.doi.org/10.13039/501100001659
    Keywords: 551.8 ; Mesozoic structural evolution ; salt tectonics ; Baltic Sea ; faults ; seismic imaging ; gravity gliding
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2022-03-24
    Description: The Late Cretaceous to Cenozoic is known for its multiple inversion events, which affected Central Europe's intracontinental sedimentary basins. Based on a 2D seismic profile network imaging the basin fill without gaps from the base Zechstein to the seafloor, we investigate the nature and impact of these inversion events on Zechstein salt structures in the Baltic sector of the North German Basin. These insights improve the understanding of salt structure evolution in the region and are of interest for any type of subsurface usage. We link stratigraphic interpretation to previous studies and nearby wells and present key seismic depth sections and thickness maps with a new stratigraphic subdivision for the Upper Cretaceous and Cenozoic covering the eastern Glückstadt Graben and the Bays of Kiel and Mecklenburg. Time‐depth conversion is based on velocity information derived from refraction travel‐time tomography. Our results show that minor salt movement in the eastern Glückstadt Graben and in the Bay of Mecklenburg started contemporaneous with Late Cretaceous inversion in the Coniacian‐Santonian. Minor salt movement continued until the end of the Late Cretaceous. Overlying upper Paleocene and lower Eocene deposits show constant thickness without indications for salt movement suggesting a phase of tectonic quiescence from the late Paleocene to middle Eocene. In the late Eocene to Oligocene, major salt movement recommenced in the eastern Glückstadt Graben. In the Bays of Kiel and Mecklenburg, late Neogene uplift removed much of the Eocene‐Miocene succession. Preserved deposits indicate major post‐middle Eocene salt movement, which likely occurred coeval with the revived activity in the Glückstadt Graben. Cenozoic salt structure growth critically exceeded salt flow during Late Cretaceous inversion. Cenozoic salt movement could have been triggered by Alpine/Pyrenean‐controlled thin‐skinned compression, but is more likely controlled by thin‐skinned extension, possibly related to the beginning development of the European Cenozoic Rift System.
    Description: In the Baltic sector of the North German Basin, minor salt movement started comremporaneous with Late Cretaceous inversion in the Coniacian‐Santonian and lasted until the end of the Late Cretaceous. A late Paleocene to middle Eocene phase of tectonic quiescense was followed by recommencing major salt movement in the Glückstadt Graben in the Late Eocene‐Oligocene. This Cenozoic phase of salt structure growth critically exceeded salt flow during the Late Cretaceous inversion and is likely controlled by thin‐skinned extension, possibly related to the beginning development of the European Cenozoic Rift System.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Keywords: ddc:551.8 ; ddc:554.3
    Language: English
    Type: doc-type:article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...