Pre-Mississippian stratigraphy and provenance of the North Slope of Arctic Alaska II: Basinal rocks of the northeastern Brooks Range and their significance in circum-Arctic evolution
Published:June 14, 2019
Justin V. Strauss, Benjamin G. Johnson, Maurice Colpron, Lyle L. Nelson, Joshua L. Perez, Jeff A. Benowitz, William P. Ward, William C. McClelland, 2019. "Pre-Mississippian stratigraphy and provenance of the North Slope of Arctic Alaska II: Basinal rocks of the northeastern Brooks Range and their significance in circum-Arctic evolution", Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens, Karsten Piepjohn, Justin V. Strauss, Lutz Reinhardt, William C. McClelland
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The Neoproterozoic–Early Devonian(?) northeast Brooks Range basinal succession of northern Alaska and Yukon represents a peri-Laurentian deep-marine carbonate and siliciclastic succession within the composite Arctic Alaska–Chukotka microplate. The basal Firth River Group consists of a mixed siliciclastic and carbonate succession that is divided into the informal Redwacke Creek, Malcolm River, and Fish Creek formations. New U-Pb detrital zircon geochronology and δ13Ccarb and 87Sr/86Sr isotopic data from these strata, in combination with previously reported and new trace fossil discoveries, suggest the Firth River Group is Cryogenian(?)–middle(?) Cambrian in age. These strata interfinger with or are depositionally overlain by the siliciclastic-dominated lower Cambrian–Middle Ordovician(?) Neruokpuk and Leffingwell (new name) formations, which potentially record a distal expression of Cambrian extension and condensed passive margin sedimentation along the northern margin of Laurentia. All of these units are unconformably overlain by the synorogenic Clarence River Group, which is divided into the informal Aichilik and Buckland Hills formations. New U-Pb detrital zircon geochronology and previous macrofossil collections suggest the Clarence River Group is Late Ordovician-Early Devonian(?) in age. Here, we present new sedimentological observations, stratigraphic subdivisions, detrital zircon U-Pb geochronology and Lu-Hf isotope geochemistry, detrital muscovite 40Ar/39Ar geochronology, and carbonate δ13Ccarb and 87Sr/86Sr isotope geochemistry from the basinal succession that revise previous tectono-stratigraphic models for this part of Arctic Alaska and support correlations with age-equivalent strata in the Franklinian basin of the Canadian Arctic Islands and Greenland.
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Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens
The circum-Arctic region has received considerable attention over the past several decades with vigorous debate focused on topics such as mechanisms for opening the Eurasian and Amerasian basins, the importance of plume-related magmatism in the development of the Arctic Ocean, and mechanisms for ancient terrane translation along the Arctic margins. In recognition of the 25th anniversary of the Circum-Arctic Structural Events (CASE) program, an international polar research effort organized and led by the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) of Germany, this volume presents results from 18 major field expeditions involving over 100 international geoscientists from a broad spectrum of disciplines. The resulting publication focuses on the Proterozoic to Cenozoic tectonic evolution of the circum-Arctic region with correlations to adjacent orogens.