Beyond the Jurassic Corridor: Exploring North American Kimberlites and their relationship to plate tectonics

The origin of intraplate magmatism is debated, with two main hypotheses having been proposed. These are deep-seated high-temperature sources (plumes), and  intraplate extension driven ultimately by plate tectonics. A test region in this debate is the 'Jurassic Corridor,' a geological feature proposed to span North America, which contains igneous rocks including kimberlites that are attributed to the Great Meteor Hotspot (GMH). Despite longstanding assumption of this model, close inspection using modern, much-expanded geological information sets shows that the existence of a Jurassic Corridor and GMH lacks support. In this paper we reassess the distribution of kimberlites in North America and on neighboring landmasses. We demonstrate the lack of a clear Jurassic Corridor and show instead that the kimberlites and related rocks are more likely linked to the breakup of the Pangaean Supercontinent and controlled by lithospheric structures. Furthermore, by comparing these findings with global plate models for the last 300 Myr we identify three prominent age peaks in North American kimberlite occurrence that broadly align with periods of heightened plate velocity with respect to Africa. Additionally, the analysis reveals in Africa two peaks in kimberlite abundance and two velocity peaks with respect to North America. Here, however, the velocity peaks occurred approximately 20-30 Myr before the kimberlite abundance peaks. These observations underscore the significance of plate kinematics in controlling kimberlite magmatism and add to a growing body of work linking periods of tectonic upheaval to kimberlite production. The implications of this extend to our broader understanding of intraplate magmatism and warrant a global revaluation of similar phenomena.