@article{144301972e1a4c9f9853745324a2e557,
title = "Xenocrystic zircon in Central New York State Kimberlites record Neoproterozoic disturbance of Grenville Basement rocks",
abstract = "Zircon grains from two central New York State (USA) Mesozoic kimberlite dikes intruding Middle and Upper Devonian sedimentary rocks were analyzed for U[sbnd]Pb and Lu[sbnd]Hf isotopes, and trace elements, and were derived from different parts of the continental crust and/or upper mantle. Zircon from the Six Mile Creek (SMC) kimberlite has variable physical properties and “felsic” chondrite normalized REE patterns, and yields dates (321–1732 Ma) compatible with entrainment of sedimentary xenoliths during accent through the upper crust. In contrast, zircon from the Taughannock Creek (TAG) kimberlite have near concordant U[sbnd]Pb dates that are distributed between intercept ages of 572 ± 25 and 960 ± 20 (2σ) Ma (MSWD = 0.61) with homogeneous Lu[sbnd]Hf systematics and 176Lu/177Hf ratios <0.0001. Examination in CL reveal TAG zircon grains vary in internal zoning and structures, but they are geochemically and isotopically similar. Their evolution includes early Neoproterozoic (ca. 950 Ma) granulite-facies metamorphism in equilibrium with garnet growth (flat to negative sloping HREE patterns and Ti-in-zircon temperatures >900 °C) during the final assemblage of the supercontinent Rodinia, followed by subsequent Pb-loss, resulting in a discordant array and decoupling of the U[sbnd]Pb and Lu[sbnd]Hf isotopic systems prior to entrainment. Concordant zircon U[sbnd]Pb dates, anchoring the lower intercept, yield an age of 596 ± 7 (2σ) Ma for the timing of Pb-loss. This most likely occurred in a zone of rifting and mafic magmatism beneath Central New York and Pennsylvania during the opening of the Iapetian Ocean.",
keywords = "Central New York State, Kimberlite, Late Neoproterozoic rifting, Lu-Hf isotopes, Middle Devonian sedimentary rocks, U-Th-Pb dates, Zircon xenocrysts",
author = "Lupulescu, {M. V.} and Chiarenzelli, {J. R.} and Fisher, {C. M.} and Hanchar, {J. M.} and Bailey, {D. G.}",
note = "Funding Information: We thank Jared Singer formerly at RPI for zircon LA-ICPMS trace element measurements. This study was partially supported by an NSERC Discovery Grant to JMH. Thanks to Markus W{\"a}lle and Rebecca Lam for their help with the LASS analyses at MUN, and Jeff Vervoort for use of the RIGL facilities at Washington State University. Dr. Mark Pecha and Nicky Giesler at the Arizona Laserchron Center are thanked for facilitation of and assistance with LA-MC-ICPMS analyses. Cory Coutre is thanked for his assistance with data collection. We thank editor Dr. Greg Shellnut and Dr. Bodo Weber and an anonymous reviewer for their help in improving the manuscript. We gratefully acknowlegde funding from the Memorial University of Newfoundland, St. Lawrence University, and the New York State Museum - New York State Education Department. Funding Information: We thank Jared Singer formerly at RPI for zircon LA-ICPMS trace element measurements. This study was partially supported by an NSERC Discovery Grant to JMH. Thanks to Markus W{\"a}lle and Rebecca Lam for their help with the LASS analyses at MUN, and Jeff Vervoort for use of the RIGL facilities at Washington State University. Dr. Mark Pecha and Nicky Giesler at the Arizona Laserchron Center are thanked for facilitation of and assistance with LA-MC-ICPMS analyses. Cory Coutre is thanked for his assistance with data collection. We thank editor Dr. Greg Shellnut and Dr. Bodo Weber and an anonymous reviewer for their help in improving the manuscript. We gratefully acknowlegde funding from the Memorial University of Newfoundland, St. Lawrence University, and the New York State Museum - New York State Education Department. Publisher Copyright: {\textcopyright} 2023 Elsevier B.V.",
year = "2023",
month = nov,
day = "1",
doi = "10.1016/j.lithos.2023.107303",
language = "English",
volume = "456-457",
journal = "Lithos",
issn = "0024-4937",
publisher = "Pergamon",
}