Figure 4.
(A) Timeline for evolution of the Midcontinent Rift (MCR) and major phases of the Grenville Orogeny (Malone et al., 2016). (B) Reconstruction of plate positions before Laurentia-Amazonia separation, schematic spreading center geometry, and relevant features (Stein et al., 2014). JBE—Jacobsville Sandstone, Bayfield Group, and other equivalent sandstones.