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DUKTIILIT MUOTOVIIVAT VS. LINEAMENTIT VS.
HAURAAT RAKENTEET
Rakoseminaari3.12.2015
GTK, Espoo
Pietari Skyttä
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IN COLLABORATION
Jussi Kinnunen, University of Turku
Jukka-Pekka Palmu, GTK
Kirsti Korkka-Niemi, University of Helsinki
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Modelling with MOVETM from
Midland Valley Exploration Ltd
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Palmu, 1999; GTK; National Land Survey3
SETTING
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Väisänen and Skyttä, 2007
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1) Structural
interpretation of the
bedrock in the area
Replacement of lineaments with
structural form lines
Recognition of major
deformation zones and their
geometries, including shear
zone terminations
• Linear patterns and
deflections into ductile shear
zones utilized
Dextral strike-slip nature of the
Somero shear zone used as the
framework for structural
interpretation OK
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Regional-scale faults (based on aeromag)
Note the parallel individual branches and the
horsetail style shear zone termination
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Fine-tuning of the
deformation zones Structural point data
Magnetic map
Bedrock map (foliations,
folds)
The ”regional” faults on
a 100k bedrock map
“Fine-tuning” will utilize
several steps and
alternative
interpretations
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Faults, revision #1, based on ductile form lines and
lithology
Fault repositioned
along fold axial trace;
cross-cutting relations
modified
Fault repositioned
along N-edge of
anomaly,
according to GTK
bedrock form lines
High
uncertainties
in the
magnetically
”pale” area
(highlighted)
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Alternative solutions
– from regional point of view
One major SZ branch
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Alternative solutions
– from regional point of view
Two major SZ branches (E-W)
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Dip analysis Structural point data
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Dip analysis LiDAR
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DEM bedrock surface (GTK) colour-mapped by elevation
2) Bedrock
DEM vs.
shear
zones
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DEM bedrock surface (GTK) vs lineaments
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Aeromag & form lines vs lineaments
- Arrows stand for glacial striations
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3) Future outlook
a) Modification of existing
bedrock surface DEMs
>> distinct breaks instead of
smooth transitions
>> consequences for
understanding the internal
stratigraphies
>> applicable in
hydrogeological modelling
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b) Use of structural geology as input data in
surface interpolations
Kriging with
orientational parameters
from the bedrock
structures…
… according to their
occurrence!
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Use of structural geology as input
data in surface interpolations - II
Planned collaboration with Canadian Survey
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More reading available…
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THANK
YOU!
