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Full-Text Articles in Physical Sciences and Mathematics
The Evolution Of Grenville Basement In The Eastern Great Smoky Mountains; Constraints From U-Pb Zircon Geochronology, Whole Rock Sm-Nd, And Feldspar Pb Geochemistry, Ryan Joel Quinn
Theses and Dissertations--Earth and Environmental Sciences
Identifying the crustal affinity of Grenville basement rocks in the Dellwood quadrangle, western NC, provides insight into the tectonic evolution of eastern Laurentia during Grenville orogenesis. U-Pb zircon geochronology of orthogneiss, augen gneiss, and mafic xenoliths in orthogneiss reveal magmatic pulses at 1130, 1180, and 1330 Ma and metamorphic episodes at 450 and 1040 Ma. Xenoliths in 1330 Ma orthogneiss are as old as 1382 Ma and represent the oldest component of Blue Ridge basement identified to-date. Feldspar Pb isotope values span a range between juvenile-Laurentian and southern-central Appalachian basement/Amazonia. Most Pb isotope data define an array consistent with crustal …
Petrologic, Geochemical, And Geochronologic Constraints On The Tectonic Evolution Of The Southern Appalachian Orogen, Blue Ridge Province Of Western North Carolina, Eric Douglas Anderson
Petrologic, Geochemical, And Geochronologic Constraints On The Tectonic Evolution Of The Southern Appalachian Orogen, Blue Ridge Province Of Western North Carolina, Eric Douglas Anderson
University of Kentucky Doctoral Dissertations
The Blue Ridge Province of western North Carolina contains a wide variety of metamorphosed igneous and sedimentary rocks that record the tectonic effects of Precambrian and Paleozoic orogenic cycles. Tectonic interpretations of the events that led to the present configuration are varied and often conflicting. This investigation examines metamorphosed mafic rocks that are widely interpreted to have formed during the closure of ocean basins. Metabasites, and specifically eclogites, have a tendency to mark tectonic sutures and frequently preserve pressure (P), temperature (T), and age data (t) that can be gleaned from mineral equilibria and U-Pb isotopic compositions. As such, the …
Origin Of Blue Ridge Basement Rocks, Dellwood Quad, Western Nc: New Evidence From U-Pb Zircon Geochronology And Whole Rock Geochemistry, Donald Franklin Loughry Jr.
Origin Of Blue Ridge Basement Rocks, Dellwood Quad, Western Nc: New Evidence From U-Pb Zircon Geochronology And Whole Rock Geochemistry, Donald Franklin Loughry Jr.
University of Kentucky Master's Theses
Terrane discrimination in polycyclic continental basement rocks is challenging due to high-grade metamorphism and intense deformation. Based on early USGS mapping the Blue Ridge basement in the Dellwood quadrangle of the eastern Great Smoky Mountains was proposed to consist of augen orthogneisses of Laurentian (Grenvillian) affinity interfolded with migmatitic hornblende and biotite paragneisses (“Carolina Gneiss”) and amphibolites of uncertain affinity. However, detailed study reveals that the hornblende gneiss of Hadley and Goldsmith (1963) is a heterogeneous map unit consisting of (1)metaplutonic rocks; (2) variably foliated and folded felsic orthogneisses; (3) strongly migmatitic, folded Hbl+Bt-bearing gneisses; (4) foliated and lineated garnet …