@article{c4f794e0855c43b1b02b10bd5e2b93fb,
title = "Three-Dimensional Evolution of the Early Paleozoic Western Laurentian Margin: New Insights From Detrital Zircon U-Pb Geochronology and Hf Isotope Geochemistry of the Harmony Formation of Nevada",
abstract = "Uranium-lead (U-Pb) geochronology and Hafnium (Hf) isotope geochemistry of detrital zircons of the Harmony Formation of north central Nevada provide new insights into the tectonic evolution of the Late Paleozoic western Laurentian margin. Using laser-ablation inductively coupled plasma mass spectrometry, 10 arenite samples were analyzed for U-Pb ages, and 8 of these samples were further analyzed for Hf isotope ratios. Three of the sampled units have similar U-Pb age peaks and Hf isotope ratios, including a 1.0–1.4 Ga peak with εHf values of +12 to −3 and a 2.5–2.7 Ga peak with εHf values of +7 to −5. The remaining seven samples differ significantly from these three, but are similar to one another; having age peaks of 1.7–1.9 Ga with εHf of +10 to −20 and age peaks of 2.3–2.7 Ga with εHf of +6 to −8. The data confirm the subdivision of the Harmony Formation into two petrofacies: quartzose (Harmony A) and feldspathic (Harmony B). The three samples with 1.0–1.4 and 2.5–2.7 Ga peaks are the Harmony A, which originated in the central Laurentian craton. The other seven samples are the Harmony B, which originated in eastern Alberta-western Saskatchewan, north of the Harmony A source. We propose that all Harmony Formation strata were deposited near eastern Alberta and subsequently tectonically interleaved with Roberts Mountains allochthon strata. We interpret that the entire package was tectonically transported south along the western Laurentian margin and then emplaced eastward onto the craton during the Late Devonian-Early Mississippian Antler orogeny.",
keywords = "Antler orogeny, Cordillera, Harmony Formation, Paleozoic tectonics",
author = "Linde, {G. M.} and Trexler, {J. H.} and Cashman, {P. H.} and G. Gehrels and Dickinson, {W. R.}",
note = "Funding Information: We would like to acknowledge the essential role that Bill Dickinson played in all of our Harmony Formation studies. He had thought much about the difficult puzzle of the Harmony over several decades and was always enthusiastic about hearing new ideas and sharing his perspective. Bill was an incomparable mentor and model for all of us, and his loss to the entire geoscience community is profound. We also acknowledge the contributions and guidance of Jim Trexler. As Linde{\textquoteright}s doctoral advisor, Jim was always open to new ideas and methods. He was a source of sound guidance and support, keeping us grounded in the reality of the rocks in the field. For both of these gentlemen, requiem aeternam dona ei, Domine, et requiescat in pace. Additionally, we thank the researchers and staff at the Arizona LaserChron center, especially Mark Pecha and Nicole Giesler and volunteer laboratory assistants Dan Sturmer of Shell Oil Company and University of Nevada, Reno graduate students Connor Newman and Kyle Basler-Reeder for critical help in Tucson. This research was funded under Arizona LaserChron National Science Foundation (NSF) grant EAR-1338583 to Gehrels. The original collecting effort for these samples was supported by NSF grants EAR-9116000 and EAR-9416933 to Gehrels and Dickinson. LaserChron analyses of some samples was supported by NSF grant EAR-0510915 to Trexler and Cashman. Linde also thanks the following organizations for generous scholarship support of her graduate work: The Raytheon Corporation Student Veterans Scholarship, the Rocky Mountain Association of Geologists Veterans Memorial Scholarship, the Nevada Petroleum and Geothermal Society, the Graduate Student Association of the University of Nevada Reno, and the Cordilleran Section of the Geological Society of America. Data supporting these analyses and conclusions can be found in the supporting information. Publisher Copyright: {\textcopyright}2017. American Geophysical Union. All Rights Reserved.",
year = "2017",
month = nov,
doi = "10.1002/2017TC004520",
language = "English (US)",
volume = "36",
pages = "2347--2369",
journal = "Tectonics",
issn = "0278-7407",
publisher = "American Geophysical Union",
number = "11",
}