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C. F. Waythomas

Publications and source records attributed to C. F. Waythomas.

23 records · Page 2Linked to original sources

Surficial geologic map of northern Adak Island, Alaska

Surficial deposits on northern Adak Island, Alaska include a variety of volcanic, glacial, eolian, and beach sediments. These deposits are the primary water-bearing units on the island and their distri- bution is shown on the accompanying surficial geologic map. An extensive sequence of volcanic debris-flow deposits (lahars) was identified on the eastern slope of Mount Moffett. The sedimentary characteristics of the lahar deposits indicate that they are related to volcanic eruptions of Mount Moffett and are evidence for Holocene volcanic activity at this volcano. Similar lahar deposits also are present on the southern slopes of Mount Adagdak. The surficial geologic map units described in the report are a basis for island-wide assess- ments of ground-water conditions, aquifer proper- ties, and general hydrogeologic conditions, and will be useful for determining the availability of potential construction materials.

Alaska↗

Flood geomorphology of Arthurs Rock Gulch, Colorado: paleoflood history

Episodic late Quaternary flooding is recorded by bouldery deposits and slackwater sediments along Arthurs Rock Gulch, an ephemeral stream west of Fort Collins, Colorado. Flood deposits consist of individual granodiorite and pegmatite boulders, boulder bars, and coarse overbank sediment that rest on erosional terrace segments along the channel. We identified evidence for at least five flood in the lower two thirds of the 1.84 km 2 drainage basin. Flood deposits are differentiated by their position above the active channel, weathering characteristics, degree of boulder burial by colluvium, amount of lichen cover, and position with respect to terrace and colluvial deposits. Age estimates for the flood deposits are based on radiocarbon dating, tree-ring analyses, and relative-age criteria from four sites in the basin. At least two floods occurred in the last 300 years; a third flood is at least 5000 years old, but likely younger than 10,000 yr BP; and the two oldest floods occurred at least 40,000 years BP.

Geomorphology↗

Overview of environmental and hydrogeologic conditions at King Salmon, Alaska

The Federal Aviation Administration is conducting preliminary environmental assessments at most of its present or former facilities in Alaska. Information about environmental conditions at King Salmon, Alaska are presented in this report. This report gives an overview of the geology, hydro- logy, and climate of the King Salmon area and describes general geohydrologic conditions. A thick alluvial aquifer underlies King Salmon and both ground water and surface water are plentiful in the area.

Open-File Report↗

Sediment yield and spurious correlation-toward a better portrayal of the annual suspendend-sediment load of rivers

Bivariate relations between annual sediment yield (tons per year per unit drainage area) and drainage-basin area are spurious because drainage-basin area is common to both axes. Two alternative methods for portraying the annual suspended-sediment load of a river are suggested. One method consists of plotting suspended-sediment load (tons per year) against distance downstream. Such plots indicate that annual suspended-sediment load does not necessarily have a linear relationship with distance. The second method consists of plotting annual suspended-sediment load against drainage-basin area. Both methods more accurately portray fundamental relations between annual sediment load and drainage-basin characteristics than does the yield-area relation because spurious correlation is avoided. Plots were made of annual suspended-sediment load versus time for several stations along each of eight rivers for the 10–15 years of available data. The plots are in-phase with respect to relative magnitude of annual sediment loads.

Geomorphology↗