Articles | Volume 17, issue 11
https://doi.org/10.5194/se-17-1219-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/se-17-1219-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The role of brittle shear zones and the associated fractures in the formation and characteristics of bedrock surface depressions in crystalline bedrock (Turku, southwestern Finland)
Department of Geology and Geology, University of Turku, Turku, Finland
Pietari Skyttä
Department of Geology and Geology, University of Turku, Turku, Finland
Structural Geology Company Oy, Turku, Finland
Kati Marjukka Ahlqvist
Geological Survey of Finland, Espoo, Finland
Nicklas Nordbäck
Geological Survey of Finland, Espoo, Finland
Pelayo Barron
Department of Natural and Health Sciences, Åbo Akademi University, Turku, Finland
Kaisa Nikkilä
Department of Natural and Health Sciences, Åbo Akademi University, Turku, Finland
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Nikolas Ovaskainen, Pietari Skyttä, Nicklas Nordbäck, and Jon Engström
Solid Earth, 14, 603–624, https://doi.org/10.5194/se-14-603-2023, https://doi.org/10.5194/se-14-603-2023, 2023
Short summary
Short summary
We studied bedrock fracturing at Åland Islands from bedrock outcrops,
digital elevation models and geophysics using multiple scales of observation.
Using the results we can compare properties of the fractures of different sizes
to find similarities and differences; e.g. we found that glacial erosion has a
probable effect on the study of larger bedrock structures. Furthermore, we
collected data from 100 to 500 m long fractures, which have previously
proved to be difficult to sample.
Jon Engström, Mira Markovaara-Koivisto, Nikolas Ovaskainen, Nicklas Nordbäck, Markku Paananen, Ismo Aaltonen, Annu Martinkauppi, Heidi Laxström, and Henrik Wik
EGUsphere, https://doi.org/10.5194/egusphere-2023-448, https://doi.org/10.5194/egusphere-2023-448, 2023
Preprint archived
Short summary
Short summary
The main purpose of this nation-wide lineament study of whole Finland is to identify potential brittle bedrock structures. The source data used for the interpretation are a light detection and ranging (LiDAR) -based hillshaded ground elevation model, a seabed elevation model (bathymetry) and several aerogeophysical rasters. The data can be used for a preliminary mapping of bedrock structures, such as shear and fault zones, that directly influence bedrock fracturing at a regional scale.
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Short summary
The elongated depressions in the bedrock are spatially coincident with major structural features of the bedrock. These depressions are covered by a sediment overburden, which prevents direct observation of the underlying structural features and necessitates multi-scale analyses of bedrock structures. These analyses show that although elongation is governed by brittle shear zones, the morphology of the bedrock surface within the depressions is controlled by fractures associated with these zones.
The elongated depressions in the bedrock are spatially coincident with major structural features...
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