The Bornholm Basin, southern Scandinavia; a complex history from Late Cretaceous structural developments to recent sedimentation

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doi: 10.1111/bor.12194
Author(s): Jensen, Jorn B.; Moros, Matthias; Endler, Rudolf
International Ocean Discovery Program, Expedition 347 Scientists, College Station, TX
Author Affiliation(s): Primary:
Geological Survey of Denmark and Greenland, Department of Marine Geology and Glaciology, Copenhagen, Denmark
Other:
Leibniz Institute for Baltic Sea Research Warnemünde, Germany
Volume Title: Baltic Sea; geology and palaeoenvironmental evolution
Volume Author(s): Arz, Helge W., editor; Leipe, Thomas; Moros, Matthias
Source: Boreas, 46(1), p.3-17; 12th colloquium on Baltic Sea marine geology; Baltic 2014, Rostock, Germany, Sept. 8-12, 2014, edited by Helge W. Arz, Thomas Leipe and Matthias Moros. Publisher: Wiley-Blackwell, Oslo, Norway. ISSN: 0300-9483 CODEN: BRESB3
Note: In English. 48 refs.; illus., incl. sects., 1 table, geol. sketch maps
Summary: The Bornholm Basin has experienced a complex history linked closely to the structural development of the Tornquist Zone strike-slip fault system. The latest major tectonic development was late Cretaceous and early Tertiary Ronne Graben inversion caused by dextral transpressional strike-slip movements focused around rigid blocks such as Bornholm. By applying the strike-slip concept, it is possible to show that the Ronne Graben inversion push-up structure was created by restraining left step-over. The fault system continues northwest and north of Bornholm where the strike-slip movement resulted in right step-over and the formation of a pull-apart basin: the northern part of the Bornholm Basin. Detailed seismo-acoustic and sediment core studies show that, despite a rather uniform present bathymetry in the central part of the Bornholm Basin, the Quaternary deposits mirror the pull-apart basin synsedimentary depositional pattern with depocentres close to the major normal faults, bounding the Christianso Ridge. IODP Site M0065 penetrated a secondary fault zone and provided detailed information on neotectonic events and on environmental changes during the Holocene. The generally rather homogeneous sediments in the cores indicate a dominance of oxic conditions in the Bornholm Basin during the Holocene. However, strong internal seismic reflectors, indirectly reflecting variations in the sediment density and the reflection coefficient, were caused by a shift to stronger laminated, organic-rich sediments that were deposited during the Medieval Warm Period (MwP). The variable depth positions of the MwP-related strong reflectors indicate large differences in the spatial and temporal sedimentation pattern in the Bornholm Basin. These differences in the depositional environment may have been caused by local neotectonic events in the basin. Abstract Copyright (2017), John Wiley & Sons, Ltd.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 16 Structural Geology; 20 Geophysics, Applied; Absolute age; Acoustical methods; Acoustical profiles; Allostratigraphy; Atlantic Ocean; Baltic Sea; Basement; Basins; Bedrock; Bornholm; Bornholm Basin; C-14; Carbon; Cenozoic; Cretaceous; Denmark; Europe; Expedition 347; Faults; Geophysical methods; Geophysical profiles; Geophysical surveys; Glacial environment; Glaciolacustrine environment; Grabens; IODP Site M0065; IODP Site M0066; Integrated Ocean Drilling Program; Isotopes; Lacustrine environment; Marine environment; Marine sediments; Mesozoic; North Atlantic; Paleoenvironment; Pull-apart basins; Radioactive isotopes; Scandinavia; Sediments; Seismic methods; Seismic profiles; Surveys; Systems; Tectonics; Upper Cretaceous; Western Europe
Coordinates: N551005 N553006 E0160004 E0150000
Record ID: 2017011923
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom