Tectonic Implications of a Remagnetization Event in the Newark Basin

The Newark basin red beds contain a secondary magnetization (the B component) acquired during the Middle Jurassic after the 5-degrees-20-degrees basin-wide northwesterly dip was imparted to the strata of the basin and after most, if not all, of the limb rotation in the Jacksonwald syncline. The B component magnetization was most likely related to the same hydrothermal event which evidently remagnetized many of the igneous intrusions in the basin and reset their K/Ar systems at 175 Ma. The remagnetization of the red beds occurred over a few million years and was approximately coincident with the transition from continental rifting to seafloor spreading in the adjacent North Atlantic. The B component magnetization direction yields a paleomagnetic pole at 74-degrees-N, 96-degrees-E (K = 63, A95 = 2.6-degrees, N = 50 sites) after structural correction for 1/3 of the Jacksonwald folding and none of the regional tilt. This pole supports recent evidence for a high-latitude model of Jurassic apparent polar wander for North America.