Physical Sciences and Mathematics Commons^™

Pace And Process Of Active Folding And Fluvial Incision Across The Kantishna Hills Anticline, Central Alaska, A. M. Bender, R. O. Lease, P. J. Haeussler, Tammy M. Rittenour, L. B. Corbett, P. R. Bierman, M. W. Caffee

Geosciences Faculty Publications

Rates of northern Alaska Range thrust system deformation are poorly constrained. Shortening at the system's west end is focused on the Kantishna Hills anticline. Where the McKinley River cuts across the anticline, the landscape records both Late Pleistocene deformation and climatic change. New optically stimulated luminescence and cosmogenic 10Be depth profile dates of three McKinley River terrace levels (~22, ~18, and ~14–9 ka) match independently determined ages of local glacial maxima, consistent with climate‐driven terrace formation. Terrace ages quantify rates of differential bedrock incision, uplift, and shortening based on fault depth inferred from microseismicity. Differential rock uplift and incision (≤1.4 …

Alaskan Marine Transgressions Record Out-Of-Phase Arctic Ocean Glaciation During The Last Interglacial, Louise Farquharson, Daniel Mann, Tammy M. Rittenour, Pamela Groves, Guido Grosse, Benjamin Jones

Geosciences Faculty Publications

Ongoing climate change focuses attention on the Arctic cryosphere’s responses to past and future climate states. Although it is now recognized the Arctic Ocean Basin was covered by ice sheets and their associated floating ice shelves several times during the Late Pleistocene, the timing and extent of these polar ice sheets remain uncertain. Here we relate a relict barrier-island system on the Beaufort Sea coast of northern Alaska to the isostatic effects of a previously unrecognized ice shelf grounded on the adjacent continental shelf. A new suite of optically stimulated luminescence dates show that this barrier system formed during one …

Feasibility Of Extending An Artificial Salmon Spawning Stream, Marx Creek Near Hyder, Alaska, Tom Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Marx Creek, near Hyder in southeast Alaska, is a groundwater-fed, artificial salmon-spawning stream that was constructed to enhance the habitat of the atypically large chum salmon. The success of the upper Marx Creek has been limited primarily by the infiltration of silty water from the Salmon River through its flood-control dike, which results in a turbid stream environment that is not conducive to salmon spawning.

The purpose of this project was to determine whether baseflow from the groundwater system is sufficient to support a proposed 1,000-foot extension of Marx Creek. The extension would be constructed approximately 500 feet east of …

Holocene Tephrostratigraphy, Southern Kenai Peninsula, Lower Cook Inlet, Alaska, Kathleen J. Lemke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes the results of a study of 33 tephra layers found within two peat sections near Anchor Point and Homer, Alaska, on the lower Kenai Peninsula. Numerous lower Cook Inlet volcanoes have been active through the Holocene. Tephra layers found at these two sites provide a partial record of their eruptive activity. The hazards that accompany this activity have increased as populations and commercial activities expand and air traffic over the region increases. The tephras analyzed for this study provide an initial geochemical database for the lower Cook Inlet volcanoes. The database is available in electronic format at …

Pre-Late-Wisconsin Glacial History Of The Naknek River Valley, Southwestern Alaska, Caleb H. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The lower Naknek River in southwestern Alaska dissects thick (~20m) exposures of Pleistocene glaciogenic sediments. The stratigraphy of the deposits and their physical, geochemical, mineralogical, and geochronological properties were studies to determine the number and timing of glacial advances represented. Multivariate data reduction methods (cluster and principal component analyses) were applied to the data to differentiate diamicton beds. The results show a clear separation of drift of the lower Naknek River valley from drift of northern Bristol Bay and from younger, moraine-comprising drift up valley. Within the Naknek River valley, however, there is no stratigraphic trend to the clusterings. The …

Late Quaternary Glacial Geology, Shoreline Morphology, And Tephrochronology Of The Lliamna/Naknek/Brooks Lake Area, Southwestern Alaska, Karen B. Stilwell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study focuses on the late-Wisconsin Brooks Lake glaciation, lake-level fluctuations, and volcanic deposits in the lliamna/Naknek/Brooks Lake area on the northern Alaska Peninsula, southwestern Alaska. The Brooks Lake glaciation consists of five stades, from youngest to oldest: Kvichak, Iliamna, Newhalen, Iliuk, and Ukak. This thesis reassigns the type Mak Hill moraine to a pre-late-Wisconsin glaciation, and considers the moraine enclosing Naknek Lake an early-late-Wisconsin deposit correlative to either the Kvichak stade, lliamna stade, or both. The presence in the Iliamna Lake valley, and the absence in the Naknek Lake valley of a two-fold earliest-late-Wisconsin Kvichak/Iliamna glacial sequence suggest that …