Utility of radiocarbon-dated stratigraphy in determining late Holocene earthquake recurrence intervals, upper Cook Inlet region, Alaska

Bartsch-Winkler, Susan; Schmoll, Henry R.

doi:10.1130/0016-7606(1992)104<0684:uordsi>2.3.co;2

Cited by 22 publications

(17 citation statements)

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“…A series of mesoscale folds and reverse faults deform Paleocene-Eocene strata exposed within ~10 km of the CMF, recording post-ca. 50 Ma shortening along the CMF (Bartsch-Winkler and Schmoll, 1992;Kassab et al, 2009;Robertson, 2014).…”

Section: Geology Of the Talkeetna Mountainsmentioning

confidence: 99%

“…1 and 2B) (Hoffman and Armstrong, 2006;Finzel et al, 2011). This is primarily based on the modern position of the Alaska Range over the subducted portion of the flat-slab, limited Miocene Talkeetna Mountain AHe bedrock cooling ages (e.g., Arkle et al, 2013), and enhanced sediment accumulation rates and sediment delivery from bedrock sources exhumed above the flat-slab region (Cook Inlet;Finzel et al, 2011Finzel et al, , 2016Tanana Basin;Benowitz et al, 2019).…”

Section: Flat-slab Subduction Of the Yakutat Microplatementioning

confidence: 99%

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Cenozoic tectono-thermal history of the southern Talkeetna Mountains, Alaska: Insights into a potentially alternating convergent and transform plate margin

et al. 2019

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The Mesozoic–Cenozoic convergent margin history of southern Alaska has been dominated by arc magmatism, terrane accretion, strike-slip fault systems, and possible spreading-ridge subduction. We apply 40Ar/39Ar, apatite fission-track (AFT), and apatite (U-Th)/He (AHe) geochronology and thermochronology to plutonic and volcanic rocks in the southern Talkeetna Mountains of Alaska to document regional magmatism, rock cooling, and inferred exhumation patterns as proxies for the region’s deformation history and to better delineate the overall tectonic history of southern Alaska. High-temperature 40Ar/39Ar thermochronology on muscovite, biotite, and K-feldspar from Jurassic granitoids indicates postemplacement (ca. 158–125 Ma) cooling and Paleocene (ca. 61 Ma) thermal resetting. 40Ar/39Ar whole-rock volcanic ages and 45 AFT cooling ages in the southern Talkeetna Mountains are predominantly Paleocene–Eocene, suggesting that the mountain range has a component of paleotopography that formed during an earlier tectonic setting. Miocene AHe cooling ages within ∼10 km of the Castle Mountain fault suggest ∼2–3 km of vertical displacement and that the Castle Mountain fault also contributed to topographic development in the Talkeetna Mountains, likely in response to the flat-slab subduction of the Yakutat microplate. Paleocene–Eocene volcanic and exhumation-related cooling ages across southern Alaska north of the Border Ranges fault system are similar and show no S-N or W-E progressions, suggesting a broadly synchronous and widespread volcanic and exhumation event that conflicts with the proposed diachronous subduction of an active west-east–sweeping spreading ridge beneath south-central Alaska. To reconcile this, we propose a new model for the Cenozoic tectonic evolution of southern Alaska. We infer that subparallel to the trench slab breakoff initiated at ca. 60 Ma and led to exhumation, and rock cooling synchronously across south-central Alaska, played a primary role in the development of the southern Talkeetna Mountains, and was potentially followed by a period of southern Alaska transform margin tectonics.

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Section: Geology Of the Talkeetna Mountainsmentioning

confidence: 99%

Section: Flat-slab Subduction Of the Yakutat Microplatementioning

confidence: 99%

Cenozoic tectono-thermal history of the southern Talkeetna Mountains, Alaska: Insights into a potentially alternating convergent and transform plate margin

et al. 2019

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“…For the eastern part of the megathrust, geologic studies within the delta of the Copper River by Plafker and Rubin (1994) and on the arms of Cook Inlet by Combellick (1994) and Bartsch-Winkler and Schmoll (1992) provide estimates of the origin times and frequencies of great earthquakes as reflected in subsidence in the sediments and peats. These estimates yield an average recurrence time of about 750 years for 1964-type events.…”

Section: Megathrust Sourcesmentioning

confidence: 99%

Revision of Time-Independent Probabilistic Seismic Hazard Maps for Alaska

Boyd¹,

Mueller²,

Bufe³

et al. 2007

Open-File Report

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“…Both models are often employed in the development of the USGS National Seismic Hazard Maps. For example, in the seismic hazard maps for Alaska the Aleutian segment of the Pacific-North American interplate thrust is characterized by a G-R distribution for M = 7-9.2, whereas the Prince William Sound segment (1964 source region) is characterized by both a G-R distribution (M = 7-8) and a characteristic rupture model (M = 9.2) with an average return time of 750 years derived from paleoseismology studies (400-500 years estimated by Bartsch-Winkler and Schmoll, 1992). For earthquakes along the Cascadia interplate thrust, the National Seismic Hazard Maps use two different models that are equally weighted : (1) a M = 9.0 characteristic earthquake with an average repeat time of 500 years F1 and (2) a series of M = 8.3 earthquakes that fill the seismogenic region of the interplate thrust every 500 years, resulting in a repeat time of 110 years for a M = 8.3 earthquake to occur anywhere in the seismic zone.…”

Section: Appendicesmentioning

confidence: 99%