TY - JOUR
T1 - Detrital zircon U-Pb geochronology and Hf isotope geochemistry of the Roberts Mountains allochthon
T2 - New insights into the early Paleozoic tectonics of western North America
AU - Linde, Gwen M.
AU - Trexler, James H.
AU - Cashman, Patricia H.
AU - Gehrels, George
AU - Dickinson, William R.
N1 - Funding Information:
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. Linde also thanks the following organizations for generous scholarship support of her graduate work: Raytheon Corporation Student Veterans Scholarship, the Rocky Mountain Association of Geologists Veteran 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.
Publisher Copyright:
© 2016 Geological Society of America.
PY - 2016
Y1 - 2016
N2 - Detrital zircon U-Pb geochronology and Hf isotope geochemistry provide new insights into the provenance, sedimentary transport, and tectonic evolution of the Roberts Mountains allochthon strata of north-central Nevada. Using laser-ablation inductively coupled plasma mass spectrometry, a total of 1151 zircon grains from six Ordovician to Devonian arenite samples were analyzed for U-Pb ages; of these, 228 grains were further analyzed for Hf isotope ratios. Five of the units sampled have similar U-Pb age peaks and Hf isotope ratios, while the ages and ratios of the Ordovician lower Vinini Formation are significantly different. Comparison of our data with that of igneous basement rocks and other sedimentary units supports our interpretation that the lower Vinini Formation originated in the north-central Laurentian craton. The other five units sampled, as well as Ordovician passive margin sandstones of the western Laurentian margin, had a common source in the Peace River Arch region of western Canada. We propose that the Roberts Mountains allochthon strata were deposited near the Peace River Arch region, and subsequently tectonically transported south along the Laurentian margin, from where they were emplaced onto the craton during the Antler orogeny.
AB - Detrital zircon U-Pb geochronology and Hf isotope geochemistry provide new insights into the provenance, sedimentary transport, and tectonic evolution of the Roberts Mountains allochthon strata of north-central Nevada. Using laser-ablation inductively coupled plasma mass spectrometry, a total of 1151 zircon grains from six Ordovician to Devonian arenite samples were analyzed for U-Pb ages; of these, 228 grains were further analyzed for Hf isotope ratios. Five of the units sampled have similar U-Pb age peaks and Hf isotope ratios, while the ages and ratios of the Ordovician lower Vinini Formation are significantly different. Comparison of our data with that of igneous basement rocks and other sedimentary units supports our interpretation that the lower Vinini Formation originated in the north-central Laurentian craton. The other five units sampled, as well as Ordovician passive margin sandstones of the western Laurentian margin, had a common source in the Peace River Arch region of western Canada. We propose that the Roberts Mountains allochthon strata were deposited near the Peace River Arch region, and subsequently tectonically transported south along the Laurentian margin, from where they were emplaced onto the craton during the Antler orogeny.
UR - http://www.scopus.com/inward/record.url?scp=84980384668&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84980384668&partnerID=8YFLogxK
U2 - 10.1130/GES01252.1
DO - 10.1130/GES01252.1
M3 - Article
AN - SCOPUS:84980384668
SN - 1553-040X
VL - 12
SP - 1016
EP - 1031
JO - Geosphere
JF - Geosphere
IS - 3
ER -