@article{4cd6a2b0450d4f08b14bb457db196618,
title = "A new, high-precision CA-ID-TIMS date for the {\textquoteleft}Kalkberg{\textquoteright} K-bentonite (Judds Falls Bentonite)",
abstract = "The numerical calibration of the base of the Devonian is poorly constrained due to several factors. Few precise radioisotopic age determinations are available from the late Silurian and Early Devonian, and the limited published data carry large error bars from older analytical methodologies. Volcanic ashfalls suitable for dating occur in the Lower Devonian of the Appalachian Basin, but have not been precisely correlated into the global chronostratigraphical scheme because of limited bio- and lithostratigraphical information. Here, we report a new U-Pb zircon radioisotopic age determination of 417.61 ± 0.12(0.23)[0.50] Ma and improved chronostratigraphical context, including revised biostratigraphy, for an ash bed in the New Scotland Formation, Helderberg Group, from the Lochkovian Stage that was previously identified as the Kalkberg K-bentonite. This new information helps to integrate the classic New York Appalachian Basin succession into global Siluro-Devonian stratigraphy, refine the calibration of the Silurian–Devonian boundary and more precisely estimate the duration of both time periods.",
keywords = "Chitinozoans, Lochkovian, U-Pb geochronology, chronostratigraphy, conodonts",
author = "McAdams, {Neo E.B.} and Schmitz, {Mark D.} and Kleffner, {Mark A.} and Jacques Verniers and Vandenbroucke, {Thijs R.A.} and Ebert, {James R.} and Cramer, {Bradley D.}",
note = "Funding Information: We are grateful for comments from three anonymous reviewers that helped improve this manuscript, as well as Editor Peter Doyle. Alyssa Bancroft, University of Iowa, photographed the conodont specimens. Tiffany Adrain, University of Iowa, provided SUI collections numbers and curation assistance. Thomas Steeman, Ghent University, took SEM images of the chitinozoans. Sabine Van Cauwenberghe, Ghent University, processed chitinozoan samples. This work was partially supported by the American Chemical Society-Petroleum Research Fund Grant #53196-DNI8 to B.D. Cramer. This paper is a contribution to IUGS/UNESCO International Geoscience Programme (IGCP) Project 591: The Early to Middle Paleozoic Revolution. Funding Information: Acknowledgements. – We are grateful for comments from three anonymous reviewers that helped improve this manuscript, as well as Editor Peter Doyle. Alyssa Bancroft, University of Iowa, photographed the conodont specimens. Tiffany Adrain, University of Iowa, provided SUI collections numbers and curation assistance. Thomas Steeman, Ghent University, took SEM images of the chitinozoans. Sabine Van Cauwenberghe, Ghent University, processed chitinozoan samples. This work was partially supported by the American Chemical Society-Petroleum Research Fund Grant #53196-DNI8 to B.D. Cramer. This paper is a contribution to IUGS/UNESCO International Geoscience Programme (IGCP) Project 591: The Early to Middle Paleozoic Revolution. Publisher Copyright: {\textcopyright} 2017 Lethaia Foundation. Published by John Wiley & Sons Ltd",
year = "2018",
month = jul,
doi = "10.1111/let.12241",
language = "English",
volume = "51",
pages = "344--356",
journal = "Lethaia",
issn = "0024-1164",
number = "3",
}