Palaeomagnetic investigation of organic-rich lacustrine deposits, Middle Old Red Sandstone, Scotland

摘要: Synopsis Organic-rich lacustrine carbonate laminites and mudstones in the Old Red Sandstone (middle Devonian) from Orcadian Basin, Scotland, contain a magnetization that resides primarily magnetite. After removal of modern viscous at low demagnetization temperatures, southerly shallow Late Carboniferous component (before tilt: decl = 184°, incl −5°, k 36, α 95 7.3, n 12 sites) is removed between 100 450°C most specimens. A regional fold test on shallowly dipping rocks inconclusive, but suggests post-folding time remanence acquisition. few specimens also northerly interpreted as antipodal equivalent direction. Rock-magnetic studies performed representative suggest remanent magnetic carrier single domain, non-interacting Partial anhysteretic measurements indicate wide range grain sizes. The Palaeozoic chemical (CRM). association CRM organic-rich source remagnetization mechanism related to diagenesis hydrocarbons.