PALEOMAGNETISM OF THE METHOW REGION, NORTH-CENTRAL WASHINGTON - STRUCTURAL APPLICATION OF PALEOMAGNETIC DATA IN A COMPLEXLY DEFORMED, VARIABLY REMAGNETIZED TERRANE

Several units retain strong and stable magnetizations that are different from the present axial dipole field direction. When partly or completely corrected to paleohorizontal, these magnetizations become less dispersed, suggesting that they were acquired before at least the last stage of Late Cretaceous deformation. A pervasive northeast-southwest streak of magnetizations at various stages of structural correlation indicates that at least some of the rocks were partly to completely remagnetized at different times during folding. Analysis of the youngest layered rocks of the Goat Peak syncline indicates that much of the remagnetization occurred when the structure was more open but still well developed. Subsequent tighter folding followed intrusion of the Fawn Peak stock. Results are a useful case study of some of the problems that arise in studying the paleomagnetism of a complicated orogenic terrane. -from Authors