Two flysch belts having distinctly different provenance suggest no stratigraphic link between the Wrangellia composite terrane and the paleo-Alaskan margin

Hults, Chad P.; Wilson, Frederic H.; Donelick, Raymond A.; O’Sullivan, Paul B.

doi:10.1130/l310.1

Cited by 59 publications

(78 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Significant 100 Ma and 93 Ma ZUPb age peaks in the Beluga (#5) and Susitna (#12) catchments, respectively, are likely derived from Late Cretaceous plutons dated within these catchments [ Riccio et al , ; Jones et al , ]. The large component of 90–110 Ma ZUPb ages in the Chulitna catchment (#11) and the minor component in other catchments may be derived from second‐cycle zircons of the Mesozoic Kahiltna flysch [ Hults et al , ] or first‐cycle zircons from unmapped Late Cretaceous plutons. On the other hand, 120–2690 Ma ZUPb ages constitute <5% of the total age distribution in all river samples except for the West Yentna (#6) and Chulitna (#11) catchments where they are more significant.…”

Section: Resultsmentioning

confidence: 99%

Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

2016

View full text Add to dashboard Cite

Cenozoic growth of the Alaska Range created the highest topography in North America, but the space‐time pattern and drivers of exhumation are poorly constrained. We analyzed U/Pb and fission‐track double dates of detrital zircon and apatite grains from 12 catchments that span a 450 km length of the Alaska Range to illuminate the timing and extent of exhumation during different periods. U/Pb ages indicate a dominant Late Cretaceous to Oligocene plutonic provenance for the detrital grains, with only a small percentage of grains recycled from the Mesozoic and Paleozoic sedimentary cover. Fission‐track ages record exhumation during Alaska Range growth and incision and reveal three distinctive patterns. First, initial Oligocene exhumation was focused in the central Alaska Range at ~30 Ma and expanded outward along the entire length of the range until 18 Ma. Oligocene exhumation, coeval with initial Yakutat microplate collision >600 km to the southeast, suggests a far‐field response to collision that was localized by the Denali Fault within a weak Mesozoic suture zone. Second, the variable timing of middle to late Miocene exhumation suggests independently evolving histories influenced by local structures. Time‐transgressive cooling ages suggest successive rock uplift and erosion of Mounts Foraker (12 Ma) through Denali (6 Ma) as crust was advected through a restraining bend in the Denali Fault and indicate a long‐term slip rate ~4 mm/yr. Third, Pliocene exhumation is synchronous (3.7–2.7 Ma) along the length of the Alaska Range but only occurs in high‐relief, glacier‐covered catchments. Pliocene exhumation may record an acceleration in glacial incision that was coincident with the onset of Northern Hemisphere glaciation.

show abstract

Section: Resultsmentioning

confidence: 99%

Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

2016

View full text Add to dashboard Cite

show abstract

“…Descriptions of the methods followed to produce and process zircon U/Pb data have been presented in Bradley et al (2009), Hultz, Wilson, Donelick, andO'Sullivan (2013) and Moore, O'Sullivan, Potter, and Donelick (2015). Zircons (both standards and unknowns) were mounted in epoxy wafers and ground and polished to expose internal grain surfaces.…”

Section: U/pb La-icp-ms Methodsmentioning

confidence: 99%

Detrital zircon and apatite constraints on depositional ages, sedimentation rates and provenance: Pliocene Productive Series, South Caspian Basin, Azerbaijan

et al. 2018

View full text Add to dashboard Cite

We used detrital zircon U/Pb geochronology and apatite (U-Th-Sm)/He thermochronology to better constrain depositional ages and sedimentation rates for the Pliocene Productive Series in Azerbaijan. U/Pb analysis of 1,379 detrital zircon grains and (U-Th-Sm)/He analysis of 57 apatite grains-from Kirmaky Valley and Yasamal Valley onshore sections, Absheron Peninsula-yielded two distinct sub-populations: "young" Neogene grains and "old" Mesozoic, Palaeozoic and Proterozoic/Archean grains. The large numbers of Neogene age grains (around 10% of all grain ages) provided a new absolute age constraint on the maximum depositional age of the Lower Productive Series of 4.0 Myr. These "young" Neogene zircon grains most likely originated from volcanic ash falls sourced from the Lesser Caucasus or Talesh Mountains. In this paper we propose a timescale scenario using the maximum depositional age of the Productive Series from detrital zircon grain U/Pb constraints. Potential consequences and limitations of using apatite (U-Th-Sm)/He dating method in estimating maximum depositional ages are also discussed. These new age constraints for the Lower Productive Series gave much faster sedimentation rates than previously estimated: 1.3 km/Myr in the South Caspian Basin margin outcrops and up to 3.9 km/Myr in the basin centre. The sedimentation rates are one of the highest in comparison to other sedimentary basins and coeval to global increase in sedimentation rates 2-4 Myr. The older group of detrital zircon grains constitutes the majority of grains in all sample sets (~80%). These older ages are inferred to reflect the provenance of the Productive Series sediment. This sediment is interpreted to have been derived from the Proterozoic and Archean crystalline basement rocks and Phanerozoic cover of the East European Craton, Proterozoic/Palaeozoic rocks of the Ural Mountains and Mesozoic sedimentary rocks of the Greater Caucasus.This sediment was likely supplied from northerly sourced drainage that emptied into the South Caspian Basin.---

show abstract

“…The end of Kahiltna and Dezadeash sedimentation in mid-Cretaceous time (~110-90 Ma) coincided approximately with onset of the deformation that initiated formation of the CCO. However, Hults et al (2013) suggest that no stratigraphic link can be made until the Late Cretaceous between a southern group of basins in mainland Alaska that overlie, and contain detritus eroded from, the Wrangellia composite terrane and its Jurassic-Cretaceous arc, and a northern group of Cretaceous basins derived from the Yukon-Tanana terrane and small terranes in central Alaska.…”

Section: (3) Northern Coast Mountains: Latitudes 55° To 62ºmentioning

confidence: 97%

Logan Medallist 1. Seeking the Suture: The Coast-Cascade Conundrum

Monger

2014

View full text Add to dashboard Cite

The boundary between rocks assigned to the Intermontane superterrane in the interior of the Canadian Cordillera and those of the Insular superterrane in the westernmost Cordillera of British Columbia and southeastern Alaska lies within/along the Coast Mountains, in which is exposed the core of an orogen that emerged as a discrete tectonic entity between 105 and 45 million years ago. Evidence from the Coast Mountains and flanking areas indicates that parts of the Intermontane superterrane (in Stikinia and Yukon-Tanana terranes) were near those of the Insular superterrane (Wrangellia and Alexander terranes) by the Early Jurassic (~180 Ma). This timing, as well as paleobiogeographic and paleomagnetic considerations, appears to discount a recent hypothesis that proposes westward-dipping subduction beneath an intra-oceanic arc on Insular superterrane resulted in arc-continent collision and inaugurated Cordilleran orogenesis in the Late Jurassic (~146 Ma). The hypothesis also relates the subducted ocean that had separated the superterranes to a massive, faster-than-average-velocity seismic anomaly in the lower mantle below the eastern seaboard of North America. To create such an anomaly, subduction of the floor of a large ocean was needed. The only surface record of such an ocean in the interior of the Canadian Cordillera is the Cache Creek terrane, which lies within the Intermontane superterrane but is no younger than Middle Jurassic (~174 Ma). This terrane, together with the probably related Bridge River terrane in the southeastern Coast Mountains, which is as young as latest Middle Jurassic (164 Ma) and possibly as young as earliest Cretaceous (≥ 130 Ma), appear to be the only candidates in Canada for the possible surface record of the seismic anomaly. SOMMAIRELa limite entre les roches assignées au Superterrane d’intermont de l’intérieur des Cordillères canadiennes et celles du Superterrane insulaire dans la portion la plus à l’ouest de la Cordillère de Colombie-Britannique et du sud-est de l’Alaska se trouvent dans et au long de la Chaîne côtière, au sein de laquelle affleure le noyau d’un orogène qui est apparu comme entité tectonique distincte entre 105 et 45 millions d’années. Des indices de la Chaîne côtière et des régions environnantes montrent que des portions du Superterrane d’intermont (dans les terranes de Stikinia et de Yukon-Tanana) se trouvaient alors près de celles du Superterrane insulaire (terranes de Wrangellia et d’Alexander) au début du Jurassique (~180 Ma). Cette chronologie, ajoutée à certains facteurs paléobiogéographiques et paléomagnétiques semblent discréditer une hypothèse récente voulant qu’une subduction à pendage ouest sous un arc intra-océanique sur le Superterrane insulaire résultait d’une collision entre un arc et le continent, initiant ainsi l’orogénèse de la Cordillère à la fin du Jurassique (~146 Ma). Cette hypothèse relie aussi l’océan subduit qui séparait les superterranes à une anomalie de vitesse sismique plus rapide que la normale dans le manteau inférieur sous le littoral maritime oriental de l’Amérique du Nord. Pour créer une telle anomalie, la subduction du plancher d’un grand océan était nécessaire. La seule indication de surface de l’existence d’un tel océan à l’intérieur de la Cordillère canadienne est le terrane de Cache Creek qui, bien qu’il se trouve dans le Superterrane d’intermont, est plus ancien que le Jurassique moyen (~174 Ma). Ce terrane, avec son équivalent probable de Bridge River dans le sud-est de la Chaîne côtière, qui est aussi jeune que la fin du Jurassique (164 Ma) et peut-être aussi jeune que le début du Crétacé (≥ 130 Ma), semblent être les seuls candidats au Canada offrant des vestiges en surface de cette anomalie sismique.

show abstract

Two flysch belts having distinctly different provenance suggest no stratigraphic link between the Wrangellia composite terrane and the paleo-Alaskan margin

Cited by 59 publications

References 90 publications

Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

Detrital zircon and apatite constraints on depositional ages, sedimentation rates and provenance: Pliocene Productive Series, South Caspian Basin, Azerbaijan

Logan Medallist 1. Seeking the Suture: The Coast-Cascade Conundrum

Contact Info

Product

Resources

About