Directions of natural remanent magnetization from Upper Devonian Catombal Group red beds retain after magnetic cleaning a large secondary component acquired after the rocks were folded. A computer program was developed to eliminate progressively this 'hard' secondary component, which was found to lie along the present dipole field direction with an average intensity 1.6 times that of the primary component. It is interpreted to be due to weathering. The best estimate of primary direction was taken as the one in which the site mean directions, after removal of some secondary component and unfolding, gave minimum dispersion. The Upper Devonian field direction at Wellington derived from this procedure is (171¿-14¿), with A95=8¿. The southern hemisphere paleomagnetic pole (49¿S, 312¿1) obtained is not significantly different from the only published Australian pole position of Upper Devonian age, from the Lochiel Formation, at (58¿S, 320¿E). |