Matches in SemOpenAlex for { <https://semopenalex.org/work/W2955122008> ?p ?o ?g. }
- W2955122008 endingPage "1101" @default.
- W2955122008 startingPage "1066" @default.
- W2955122008 abstract "Abstract The Alaska Range suture zone exposes Cretaceous to Quaternary marine and nonmarine sedimentary and volcanic rocks sandwiched between oceanic rocks of the accreted Wrangellia composite terrane to the south and older continental terranes to the north. New U-Pb zircon ages, 40Ar/39Ar, ZHe, and AFT cooling ages, geochemical compositions, and geological field observations from these rocks provide improved constraints on the timing of Cretaceous to Miocene magmatism, sedimentation, and deformation within the collisional suture zone. Our results bear on the unclear displacement history of the seismically active Denali fault, which bisects the suture zone. Newly identified tuffs north of the Denali fault in sedimentary strata of the Cantwell Formation yield ca. 72 to ca. 68 Ma U-Pb zircon ages. Lavas sampled south of the Denali fault yield ca. 69 Ma 40Ar/39Ar ages and geochemical compositions typical of arc assemblages, ranging from basalt-andesite-trachyte, relatively high-K, and high concentrations of incompatible elements attributed to slab contribution (e.g., high Cs, Ba, and Th). The Late Cretaceous lavas and bentonites, together with regionally extensive coeval calc-alkaline plutons, record arc magmatism during contractional deformation and metamorphism within the suture zone. Latest Cretaceous volcanic and sedimentary strata are locally overlain by Eocene Teklanika Formation volcanic rocks with geochemical compositions transitional between arc and intraplate affinity. New detrital-zircon data from the modern Teklanika River indicate peak Teklanika volcanism at ca. 57 Ma, which is also reflected in zircon Pb loss in Cantwell Formation bentonites. Teklanika Formation volcanism may reflect hypothesized slab break-off and a Paleocene–Eocene period of a transform margin configuration. Mafic dike swarms were emplaced along the Denali fault from ca. 38 to ca. 25 Ma based on new 40Ar/39Ar ages. Diking along the Denali fault may have been localized by strike-slip extension following a change in direction of the subducting oceanic plate beneath southern Alaska from N-NE to NW at ca. 46–40 Ma. Diking represents the last recorded episode of significant magmatism in the central and eastern Alaska Range, including along the Denali fault. Two tectonic models may explain emplacement of more primitive and less extensive Eocene–Oligocene magmas: delamination of the Late Cretaceous–Paleocene arc root and/or thickened suture zone lithosphere, or a slab window created during possible Paleocene slab break-off. Fluvial strata exposed just south of the Denali fault in the central Alaska Range record synorogenic sedimentation coeval with diking and inferred strike-slip displacement. Deposition occurred ca. 29 Ma based on palynomorphs and the youngest detrital zircons. U-Pb detrital-zircon geochronology and clast compositional data indicate the fluvial strata were derived from sedimentary and igneous bedrock presently exposed within the Alaska Range, including Cretaceous sources presently exposed on the opposite (north) side of the fault. The provenance data may indicate ∼150 km or more of dextral offset of the ca. 29 Ma strata from inferred sediment sources, but different amounts of slip are feasible. Together, the dike swarms and fluvial strata are interpreted to record Oligocene strike-slip movement along the Denali fault system, coeval with strike-slip basin development along other segments of the fault. Diking and sedimentation occurred just prior to the onset of rapid and persistent exhumation ca. 25 Ma across the Alaska Range. This phase of reactivation of the suture zone is interpreted to reflect the translation along and convergence of southern Alaska across the Denali fault driven by highly coupled flat-slab subduction of the Yakutat microplate, which continues to accrete to the southern margin of Alaska. Furthermore, a change in Pacific plate direction and velocity at ca. 25 Ma created a more convergent regime along the apex of the Denali fault curve, likely contributing to the shutting off of near-fault extension-facilitated arc magmatism along this section of the fault system and increased exhumation rates." @default.
- W2955122008 created "2019-07-12" @default.
- W2955122008 creator A5004534779 @default.
- W2955122008 creator A5017377136 @default.
- W2955122008 creator A5045629630 @default.
- W2955122008 creator A5079608896 @default.
- W2955122008 date "2019-06-26" @default.
- W2955122008 modified "2023-10-16" @default.
- W2955122008 title "Cretaceous to Miocene magmatism, sedimentation, and exhumation within the Alaska Range suture zone: A polyphase reactivated terrane boundary" @default.
- W2955122008 cites W101608520 @default.
- W2955122008 cites W1500491358 @default.
- W2955122008 cites W1552779518 @default.
- W2955122008 cites W1606895067 @default.
- W2955122008 cites W1826161772 @default.
- W2955122008 cites W1863018253 @default.
- W2955122008 cites W1886938672 @default.
- W2955122008 cites W1900353601 @default.
- W2955122008 cites W1915451597 @default.
- W2955122008 cites W1918684828 @default.
- W2955122008 cites W1919717877 @default.
- W2955122008 cites W1937144719 @default.
- W2955122008 cites W1966135873 @default.
- W2955122008 cites W1968557313 @default.
- W2955122008 cites W1973926757 @default.
- W2955122008 cites W1976203747 @default.
- W2955122008 cites W1982392939 @default.
- W2955122008 cites W1985784461 @default.
- W2955122008 cites W1987135569 @default.
- W2955122008 cites W1994492975 @default.
- W2955122008 cites W1996548974 @default.
- W2955122008 cites W1997040345 @default.
- W2955122008 cites W1999125016 @default.
- W2955122008 cites W1999621813 @default.
- W2955122008 cites W2002178446 @default.
- W2955122008 cites W2002777547 @default.
- W2955122008 cites W2003174797 @default.
- W2955122008 cites W2003321069 @default.
- W2955122008 cites W2008451537 @default.
- W2955122008 cites W2010119110 @default.
- W2955122008 cites W2010730984 @default.
- W2955122008 cites W2012088192 @default.
- W2955122008 cites W2013883793 @default.
- W2955122008 cites W2014178080 @default.
- W2955122008 cites W2021952952 @default.
- W2955122008 cites W2024275446 @default.
- W2955122008 cites W2025225522 @default.
- W2955122008 cites W2027266634 @default.
- W2955122008 cites W2027340397 @default.
- W2955122008 cites W2028226307 @default.
- W2955122008 cites W2028764674 @default.
- W2955122008 cites W2030958259 @default.
- W2955122008 cites W2034314180 @default.
- W2955122008 cites W2035360089 @default.
- W2955122008 cites W2040029696 @default.
- W2955122008 cites W2047192300 @default.
- W2955122008 cites W2049321728 @default.
- W2955122008 cites W2057204790 @default.
- W2955122008 cites W2064590568 @default.
- W2955122008 cites W2071782561 @default.
- W2955122008 cites W2076768810 @default.
- W2955122008 cites W2077380876 @default.
- W2955122008 cites W2078214542 @default.
- W2955122008 cites W2082323314 @default.
- W2955122008 cites W2084994385 @default.
- W2955122008 cites W2086424708 @default.
- W2955122008 cites W2088196174 @default.
- W2955122008 cites W2089035678 @default.
- W2955122008 cites W2093326692 @default.
- W2955122008 cites W2093671367 @default.
- W2955122008 cites W2094651119 @default.
- W2955122008 cites W2095601024 @default.
- W2955122008 cites W2100025525 @default.
- W2955122008 cites W2105264979 @default.
- W2955122008 cites W2108971421 @default.
- W2955122008 cites W2110603116 @default.
- W2955122008 cites W2111447315 @default.
- W2955122008 cites W2111648643 @default.
- W2955122008 cites W2116718662 @default.
- W2955122008 cites W2126352160 @default.
- W2955122008 cites W2127572779 @default.
- W2955122008 cites W2128209044 @default.
- W2955122008 cites W2133418367 @default.
- W2955122008 cites W2136136321 @default.
- W2955122008 cites W2136372949 @default.
- W2955122008 cites W2138772176 @default.
- W2955122008 cites W2140996342 @default.
- W2955122008 cites W2143258775 @default.
- W2955122008 cites W2144843504 @default.
- W2955122008 cites W2146299099 @default.
- W2955122008 cites W2151527887 @default.
- W2955122008 cites W2156712600 @default.
- W2955122008 cites W2159668333 @default.
- W2955122008 cites W2161188118 @default.
- W2955122008 cites W2165555300 @default.
- W2955122008 cites W2168113119 @default.
- W2955122008 cites W2169496793 @default.
- W2955122008 cites W2170212407 @default.
- W2955122008 cites W2171125516 @default.