Collaborative Research: Evolution of the Midcontinent Rift as a Rift/Lip Hybrid

Northwestern (Seth Stein and Ph.D. student Edward Brooks) will work with UIC (Carol Stein) to continue ongoing joint work, focusing in this proposal on exploration of the tectonic setting and kinematics of MCR evolution. Both will involve combining data from the MCR with insights from present and younger rifts, where data are far more abundant and the tectonic history is much better known. They will also continue ongoing programs promoting public understanding of the MCR's significance and of new research about it. Northwestern will take the lead on investigating rifting kinematics by using the GPLATES software to generate synthetic APW paths corresponding to those relative motions and assign precise ages to points on the path, for comparison with the actual paths and the history of extension and magmatism. This will show how in detail the cusp reflects the rifting history. Perturbing the seafloor spreading history within its uncertainties will give a range of possible rift histories and allow examination of the resulting APW paths. In particular, we can see how much extension can occur before a cusp develops. The results will give insight into both the MCR and continental rifting in general. Northwestern will also manage the interface with the group at UTEP who are developing a new freely available suite of software for the analysis of gravity and magnetic data that will be used in the project.