Dichiarante, A.M. and Holdsworth, R.E. and Dempsey, E.D. and Selby, D. and Mccaffrey, K.J.W. and Michie, U. and Morgan, G. and Bonniface, J. (2016) 'New structural and Re–Os geochronological evidence constraining the age of faulting and associated mineralization in the Devonian Orcadian Basin, Scotland.', Journal of the Geological Society., 173 (3). pp. 457-473.
The Devonian Orcadian Basin in northern Scotland belongs to a regionally linked system of post-Caledonian continental basins extending northwards to western Norway and eastern Greenland. Extensional fault systems that cut the Orcadian Basin sequences are commonly assumed to be Devonian, with some limited inversion and reactivation proposed during the Carboniferous and later times. We present a detailed structural study of the regionally recognized fault systems exposed in the Dounreay area of Caithness, which host significant amounts of authigenic mineralization (carbonate, base metal sulphides, bitumen). Structural and microstructural analyses combined with Re–Os geochronology have been used to date syndeformational fault infills (pyrite) suggesting that faulting, brecciation and fluid flow events are likely to have occurred during the Permian (267.5 ± 3.4 [3.5] Ma). Stress inversion of fault slickenline data associated with mineralization suggest NW–SE regional rifting, an episode also recognized farther west in Sutherland. Thus a dominant set of Permian age brittle faults is now recognized along the entire north coast of Scotland, forming part of the regional-scale North Coast Transfer Zone located on the southern margin of the offshore West Orkney Basin.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||http://dx.doi.org/10.1144/jgs2015-118|
|Publisher statement:||Journal of the Geological Society, 173, 457-473, May 2016, http://dx.doi.org/10.1144/jgs2015-118 © Geological Society of London 2016.|
|Date accepted:||01 December 2015|
|Date deposited:||04 December 2015|
|Date of first online publication:||19 February 2016|
|Date first made open access:||19 February 2017|
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