Open AccessReappraisal of Scottish Ordovician palaeomagnetism
Author(s) -
Storetvedt K. M.,
Deutsch E. R.
Publication year - 1986
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1986.tb01990.x
Subject(s) - ordovician , paleomagnetism , geology , clockwise , overprinting , paleontology , earth's magnetic field , apparent polar wander , tectonics , rotation (mathematics) , geometry , physics , mathematics , quantum mechanics , magnetic field
Summary. Critical re‐evaluation of Scottish Ordovician palaeomagnetism comprising data from the NW Scotland syenites, the Aberdeenshire gabbros, and the pre‐tectonic (i.e. pre late Ordovician‐Silurian) magnetic overprinting of Dalradian tillites, appears to provide a refined mid‐Ordovician to Silurian apparent polar wander path. ‘Post‐closure’ magnetizations (Silurian) across the Great Glen Fault agree extremely well after correction for a 20d̀ net clockwise rotation of the Northern Highlands. The data emphasize a previous assumption that some of the existing discrepancies in British Ordovician palaeomagnetism may disappear when the prevalence of multicomponent magnetizations is adequately considered. The data also support the conclusion from an earlier analysis requiring an anticlockwise rotation of the British Isles relative to the geomagnetic field during the Ordovician. However, a recent suggestion that the Aberdeenshire gabbros record the slow post‐orogenic cooling of the NE Highlands is shown to rest on an inadequate palaeomagnetic basis.