The British Tertiary Igneous Province: Palaeomagnetism and Ages of Dykes, Lundy Island, Bristol Channel

Of 66 dykes collected 52 gave stable directions: 44 reversed, 4 normal and 4 intermediate. The mean direction of magnetization was N3.6°E, + 62.7° (down,) equivalent to a pole position of 82.6°N, 155.0°E. This is significantly different from the present pole and displays right-handed farsidedness. The bulk, at least, of the dykes fall within the apparent span 45-54 My. Yet they display approximately the same small proportion of normal dykes as do the older dyke swarms of the province which were formed during a different polarity period or periods.