Zircon U-Pb-Hf isotope evidence for juvenile Penokean sources (ca. 1.9 Ga) in the SW Grenville Province

The Proterozoic evolution of Laurentia involved intermittent orogens and arc-related crustal growth along a modern-style convergent margin, termed the Great Proterozoic Accretionary Orogen (GPAO). The major lithotectonic provinces of the GPAO in the United States are exposed as telescoped equivalents within the thrust stack of the Grenville Province in Canada. We report zircon UPb and LuHf isotope analyses for two orthogneisses and one …