Juha Köykkä - Oulu

Res Terrae, Ser. A 32, J. Köykkä, Sedimentology of the Mesoproterozoic Telemark basin-fills, South Norway: implications for
sedimentation processes, depositional environments and tectonic evolution
the driving mechanisms and stress environments in which the sedimentary basin was
created. From a genetic point of view, the sedimentary basin classification can be
simply subdivided into the following: (i) extensional basins controlled by heating of
the lithosphere from below and stretching and thinning of the crust, leading to rifting
and thick sedimentation prisms (e.g., rifts and passive margins); (ii) pull-apart basins
controlled by same mechanisms and formed in shear settings; and (iii) compressional
basins, where contraction process caused crustal thickening, leading to local loads and
isostatic subsidence (e.g., forelands, back-arcs, and ocean trenches).
Sedimentation in a basin is generally controlled by a combination of autogenic (in-
ternal) and allogenic (external) processes. The relative importance of each mechanism
depends mostly on basin configuration and proximal vs. distal settings. Autogenic
processes can be studied by lithofacies analysis, but allogenic processes also require an
understanding of sequence stratigraphy, geochemistry, and possible clastic petrofacies.
These processes determine the distribution of depositional elements within a deposi-
tional system in a sedimentary basin (e.g., Ingersoll and Busby, 1985; Allen and Allen,
1990; Einsele, 2000; Miall, 2000). Allogenic controls on sedimentation and accommo-
dation space in basins are controlled by the interactions of climate, tectonics and sea
level changes (Fig. 8). Eustasy is mainly controlled by tectonics and climate, whereas
climate is mainly controlled by global orbital forcing or possible local tectonism (e.g.,
formation of thrust belts). Tectonics is driven by the Earth’s internal dynamics (plume
and plate tectonic processes). The sediment supply is mainly controlled by climate,
tectonism, transportation, and the nature of the provenance.
In Paper IV, the paleotectonic and plate-reconstruction of the studied sedimentary
basin is studied by combining all of the available data. The reconstruction was based
on the methods and tools described above.
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