9706692 Mosher A leading problem in understanding the late Proterozoic of North America relates to the Grenville orogeny and its relationship to the crustal blocks involved in it. South of the great lakes exposure of the relevant rocks is almost non-existent, and thus the exposures of the Llano uplift, and those in west Texas become unusually critical in deciphering these relationships. In fact, the exposures that do exist there seem to reveal a rather more complicated history of not only typical lower crustal Grenville rocks, but also eclogites, possible fragments of the mid continental Grainte-Rhyolite terrane, and a so-far unrecognized volcanic terrane. This geochronological, petrological, and structural study of these rocks will provide fundamental limiting and defining data that will strongly constrain our understanding of the tectonic evolution of the southern Grenville region.
Mesoproterozoic Tectonic Evolution of the Southern Margin of Laurentia