U-Pb geochronology of baddeleyite from the Belleview metadiabase: Age and geotectonic implications for the Negaunee Iron Formation, Michigan

This new date does not support a more recently proposed synorogenic foredeep depositional environment for the deposition of the Negaunee Iron Formation. Instead, this age date supports an earlier interpretation that the Negaunee Iron Formation is part of continental shelf deposits laid down prior to onset of 1875-1835 Ma collision. The age of the Belleview sill suggests that it is the result of extension-related magmatism that is prior to the currently defined Penokean orogenic event.