Pre-Mississippian stratigraphy and provenance of the North Slope subterrane of Arctic Alaska I: Platformal carbonate rocks of the northeastern Brooks Range and their signifi cance in circum-Arctic evolution
Published:June 14, 2019
Justin V. Strauss, Francis A. Macdonald, William C. McClelland, 2019. "Pre-Mississippian stratigraphy and provenance of the North Slope subterrane of Arctic Alaska I: Platformal carbonate rocks of the northeastern Brooks Range and their signifi cance 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 platformal succession of the North Slope subterrane, northeastern Brooks Range, Alaska, represents a carbonate-dominated peri-Laurentian continental fragment within the composite Arctic Alaska–Chukotka microplate. The basal ca. 760–720 Ma Mount Weller Group consists of an ~400 m thick mixed siliciclastic and carbonate succession that records the onset of regional extensional tectonism associated with the separation of southeastern Siberia from northern Laurentia during the break-up of Rodinia. These strata are overlain by ca. 720 Ma continental flood basalts of the Kikiktat volcanic rocks, which provide a link between the northeast Brooks Range platformal succession and the ca. 723–717 Ma Franklin large igneous province (LIP) of northern Laurentia. The overlying Sturtian Hula Hula diamictite and Cryogenian–Ediacaran Katakturuk Dolomite record abbreviated thermal subsidence of the northeast Brooks Range platformal succession prior to renewed Ediacaran–early Cambrian extensional tectonism and deposition of the overlying lower Paleozoic Nanook Group (new name). Equivalent strata of the deep-water Cryogenian–lower Cambrian(?) Ikiakpuk Group (new name) are identified herein with new δ13Ccarb and 87Sr/86Sr isotopic data from the Fourth Range of the northeastern Brooks Range. The Nanook Group is formally divided herein into the Black Dog and Sunset Pass formations, which record isolated peri-Laurentian platformal carbonate sedimentation along the northern margin of Laurentia, in an analogous tectonic position to the modern Bahama Banks. A profound Late Ordovician(?)-Early Devonian unconformity within the platformal succession is marked by subaerial exposure, paleokarst development, and tilting of the northeast Brooks Range peri-Laurentian platformal fragment prior to deposition of the overlying Lower Devonian Mount Copleston Limestone.
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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.