Magnetic characterization of the zigzag shaped J-anomaly: Implications for kinematics and breakup processes at the Iberia-Newfoundland margins

Lithospheric breakup is generally defined as the process that results in a new plate boundary and oceanic crust. However, how this process occurs in magma-poor systems remains debated. As recently suggested, the J-magnetic anomaly at the Iberia-Newfoundland margins has polygenic sources and therefore cannot be interpreted as an isochron. However, the presence of the J-anomaly on both margins suggests a common origin. By using analytic signal map of magnetic data, we highlight landward zigzagged limits for the J-anomalies at the Iberian-Newfoundland margins. The zigzag segments neither match the axis nor the transform systems of previously proposed plate reconstructions, but are aligned with NE-SW Palaeozoic trends. However, they can be fitted using recently published plate restorations, as expected if they have a single origin. Therefore, a link between the location of syn- to post-breakup magmatic additions along the J-anomaly and an inherited lithospheric trend is proposed.