Palaeomagnetic results suggest that several fluid flow events caused alteration and hematite authigenesis in the Moine Thrust Zone, northwest Scotland, between the Late Palaeozoic and Middle Tertiary. Precambrian Torridonian sandstone and Lewisian gneiss in the fault zone on the Isle of Skye contain a Tertiary magnetization interpreted to be the result of hydrothermal fluids associated with Tertiary intrusions. Samples of the Durness Formation limestone (Cambrian), Torridon Group and quartzites (Cambrian) in and near the fault zone to the north contain a Late Palaeozoic to Triassic magnetization residing in hematite and interpreted to be related to hydrothermal fluids. This magnetization and associated alteration in the Moine Thrust Zone are direct evidence for post-orogenic activity, in which the thrusts vented excess heat during regional crustal extension. (C) 2003 Elsevier Science B.V. All rights reserved.
- Moine Fault
- tertiary igneous rock