Paleomagnetic study of intrusive rocks in the Oregon Coast Range shows clockwise rotation of the range relative to North America of 51.5° ± 30.0° since late Eocene–early Oligocene time, 44.5° ± 17.0° since middle Oligocene time, and possibly 32.0° ± 26.5° since middle Miocene time. The simplest interpretation of paleomagnetic data currently available for the Coast Range indicates that it rotated steadily at a rate of about 1.5°/m.y. for approximately the period 50 to 20 m.y. B.P. Events since the middle Miocene are entirely unresolved.

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