This chapter reviews paleomagnetic data on igneous rocks in the Culpeper, Newark, and Hartford/Deerfield basins, beginning with the work of DuBois and others (1957) and extending through 1990. Data from published articles is supplemented with unpublished data from theses and individual projects currently in progress.

Analysis of these data support Prevot and McWilliams’ (1989) correlation of the Orange Mountain, Preakness, and Hook Mountain Basalts with the Talcott, Holyoke, and Hampden Basalts, respectively. Their correlation of the Deerfield Basalt with the Holyoke Basalt and the Preakness Basalt is also supported, and the unpublished data presented here support extending this correlation to the Sander Basalt in the Culpeper basin. Additionally, it is suggested that the anomalous magnetization of this group of rocks may provide evidence of an excursion of the magnetic pole.

The data presented in this review do not support the separation of igneous activity into two separate events as suggested by Smith and Noltimier (1979). A single period of igneous activity producing both intrusive and volcanic rocks and restricted to a relatively short period of time at the beginning of the Jurassic seems more likely. Furthermore, the N1 and N2 poles of Smith and Noltimier (1979) are not representative of Newark Supergroup igneous rocks and that they should be abandoned in calculating North American apparent polar wander paths.