40Ar/39 Ar age spectra have been obtained for biotites and hornblendes representing a suite of diabase dikes from the northern part of Newfoundland's Gandez Zone. A age of 375=10 Ma is suggested a value probably very close to the age of intrusion. A number of the age spectra and discordant; this perhaps results from a disturbing 'event' ~180 Ma ago. Magnetic analysis of the dike swarm has yielded four paleopoles; three of these magnetizations appear to be carried by multi-domain magnetite, the other by hematite. If the magnetite magnetizations are primary, they possibly reflect a period of aberrant geomagnetic field behaviour at about the time given above. On the other hand, if the hematite magnetization is primary, the data can be interpreted in terms of the displaced terrain model of Kent and Opdyke. However, our data imply that the relative southern displacement of Acadia in the Devonian may be smaller than these authors have suggested.