Paleomagnetic results from the Peterhead granite,Scotland; implication for regional late Caledonian magnetic overprinting

Palaeomagnetic results from the Peterhead granite (Silurian), NE Grampian Highlands, define a characteristic magnetization with overall parameters of Dec: 180.4°, Inc: 22.3° and a₉₅: 5.2°. These results agree with other “Newer Granite” data from North Scotland. An east-west trending dyke cutting the Peterhead granite shows an extremely well-defined paleomagnetic direction with Dec: 192.5°, Inc: ?19.1° and a₉₅: 1.3°, suggesting a Permo-Carboniferous age. The Peterhead Granite results are seen in conjunction with other Palaeozoic palaeomagnetic data from Scotland. It is concluded that the observed directional spread of characteristic remanence directions previously reported from the Aberdeenshire Gabbros are not related to slow post-orogenic cooling (Watts and Briden), but is rather seen as the result of late Caledonian magnetic overprinting.