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.