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Full-Text Articles in Physical Sciences and Mathematics
Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman
Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman
Earth and Environmental Sciences Faculty Publications
Basement cores from two wells drilled west and east of the Grenville front consist of feldspathic litharenite and granitic orthogneiss, respectively. Detrital zircon U-Pb ages for the litharenite define a broad dominant U-Pb age mode at ca. 1115 Ma. The dominant mode matches that for the type locality of the Middle Run Formation in the Ohio subsurface and is interpreted to consist of detrital zircons sourced from East Continent Rift volcanic sources (ca. 1100 Ma) and Grenville Shawinigan granites/gneisses (1120–1180 Ma). The youngest detrital zircon ages (ca. 1020 Ma) require a maximum depositional age that is at least 70 My …
Age Of The Walden Creek Group, Western Blue Ridge Province: Resolving A Decades-Old Controversy Via Detrital Mineral Geochronology And Sedimentary Provenance Analysis, Evan A. Kelly
Theses and Dissertations--Earth and Environmental Sciences
Originally mapped as Precambrian and uppermost Ocoee Supergroup (OS), recent discoveries of Paleozoic microfossils have placed the Walden Creek Group (WCG), eastern Tennessee, into a younger depositional framework (Silurian or younger). In this study, monazite geochronology using SIMs, detrital zircon U-Pb geochronology determined by LA-ICP-MS, feldspar compositions determined by microprobe, zircon-tourmaline-rutile (ZTR) indices, and framework mineral modes were used to characterize provenance of sandstones of the WCG. Monazite ages cluster at 450 and 1050 Ma. All Ordovician ages are from grains that, in BSE images, have inclusion-rich microtextures interpreted as diagenetic and/or metamorphic, thus requiring that the WCG was deposited …
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 …