Synchronous Emplacement of the Anorthosite Xenolith‐Bearing Beaver River Diabase and One of the Largest Lava Flows on Earth

New geochronologic and paleomagnetic data from the North American Midcontinent Rift (MCR) reveal synchronous emplacement of Beaver River diabase, anorthosite xenoliths within it, Greenstone Flow—one largest lava flows on Earth. A U-Pb zircon date 1091.83 0.21 Ma (2) one is consistent with cumulate forming as part MCR provides a maximum age constraint for diabase. Paired minimum cross-cutting Silver Bay intrusion (1091.61 0.14 Ma; 2), these tightly bracket diabase to be 1091.7 0.2 (95% CI), coeval eruption Flow (1091.59 0.27 2)—which further supported by indistinguishable tilt-corrected pole positions. Geochronological, paleomagnetic, mineralogical geochemical are hypothesis that was feeder system Flow. The large areal extent intrusives estimated volume volcanics suggest they represent rapid voluminous ca. 1,092 magmatic pulse near end main stage magmatism.