Late Caledonian (Devonian) Basin Formation, Western Norway: Signs of Strike-Slip Tectonics during Infilling

  1. Peter F. Ballance and
  2. Harold G. Reading
  1. Ron Steel and
  2. Tor Gunnar Gloppen

Published Online: 20 APR 2009

DOI: 10.1002/9781444303735.ch6

Sedimentation in Oblique-Slip Mobile Zones

Sedimentation in Oblique-Slip Mobile Zones

How to Cite

Steel, R. and Gloppen, T. G. (2009) Late Caledonian (Devonian) Basin Formation, Western Norway: Signs of Strike-Slip Tectonics during Infilling, in Sedimentation in Oblique-Slip Mobile Zones (eds P. F. Ballance and H. G. Reading), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303735.ch6

Author Information

  1. Geological Institute (A), University of Bergen, Norway

  1. Statoil, Stavanger, Norway

Publication History

  1. Published Online: 20 APR 2009
  2. Published Print: 11 SEP 1980

ISBN Information

Print ISBN: 9780632006076

Online ISBN: 9781444303735

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Keywords:

  • Late Caledonian (Devonian) basin formation - signs of strike-slip tectonics;
  • Fanglomerate, containing augengneiss;
  • lateral migration, resulting in upwards fining;
  • Devonian faulting and Californian Holocene faulting, being analogous;
  • Solund and Haasteinen Basins, resulting from normal faulting

Summary

Some of the Devonian, late orogenic basins of western Norway are likely to have developed along strike-slip faults generated in response to the latest stages of Iapetus Ocean closure and continental collision. General characteristics of these basins such as elongate shape, high sedimentation rates, extremely thick sedimentary piles compared to basin area, rapid lateral facies variations and scarce igneous/metamorphic activity are consistent with a hypothesis of strike-slip origin. More specific features such as mappable proximal onlap of successive basin-fill segments, significant basin asymmetry with regard to both sediment facies and sequence thickness and dominant longitudinal mode of basin infill are all indicative of such a mode of origin while mis-matches between fan materials and geology of adjacent drainage area, skewed fan-body geometry and the direction of onlap with respect to sediment transport all suggest a dextral sense of fault movement. Sedimentary facies draping the strike-slip basin margin (north) are conglomerates, mainly of sediment gravity flow origin deposited on small alluvial fans and fan deltas, which consistently interfinger and mix with floodbasin and lacustrine fines from the basin axis, fluvial/lacustrine delta system. Conglomerates draping the ‘normal’ basin margin (south) are of both mass flow and stream flow facies and formed on larger alluvial fans. The sedimentary pile is permeated by cyclothems of dominantly upward coarsening character (irrespective of facies) and, in places, demonstrably basin-wide. Sequences of the order of 5–20 m in thickness are thought to have been the response to largely vertical basin floor movements, while superimposed sequences some 100–200 m thick (the onlapping segments) are likely to have been deposited between intervals of mainly strike-slip movement. Data from one area, after some assumptions about basin segment geometry, suggest an average horizontal component of movement some two to three times greater than the vertical one. The difficulties of establishing a set of criteria which can be used to distinguish strike/oblique-slip generated sedimentation from rift sedimentation are discussed.