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Data Release for Luminescence: Geologic map of Scoggins Dam, Henry Hagg Lake, and the Scoggins Valley area, Washington County, Oregon

Dates

Publication Date
Start Date
2018
End Date
2021

Citation

Mahan, S.A., Krolczyk, E.T., and Redwine, J., 2022, Data Release for Luminescence: Geologic map of Scoggins Dam, Henry Hagg Lake, and the Scoggins Valley area, Washington County, Oregon: U.S. Geological Survey data release, https://doi.org/10.5066/P9PVK0Q3.

Summary

The Bureau of Reclamation's Scoggins Dam lies within the Gales Creek fault zone southwest of Hillsboro, Oregon. Recent geologic mapping shows the dam to overlie a potentially active strand of the fault. This report describes the geology of the dam in detail and confirms that the dam overlies a strand of the Gales Creek fault. The report documents small faults in the reservoir and off the north end of the dam along the Parsons Creek strand of the fault. The report further documents the geology of an alternative dam site downstream of the existing dam.

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Attached Files

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HenryHaggLake_Data.csv 19.95 KB text/csv
HenryHaggLake_Data_Dictionary.csv 7.82 KB text/csv

Purpose

Detailed geologic mapping of the structurally complex Scoggins Dam area is necessary to provide the information needed for Reclamation’s Scoggins Dam Corrective Action Study. The main objectives of this report are to: 1. Establish the location of the main, active strands of the GCF in the vicinity of the existing dam. Are the Scoggins Creek and Parsons Creek strands as mapped by Wells and others (2020a, b) the main strands of the GCF in the Scoggins Valley area? 2. Establish whether the Scoggins Creek strand underlies Scoggins Dam. 3. Document in detail the bedrock structure of the existing dam and reservoir. 4. Confirm the existence of a right stepover in the vicinity of Scoggins Dam that transfers slip between the Scoggins Creek and Parsons Creek fault strands. 5. Document the lateral extent of complex faulting related to the stepover and establish whether any of these structures pass through the proposed new dam site downstream of the existing dam. 6. Document the structure of the Scoggins Valley narrows, the proposed new dam site (Option 3 of Maguire, 2018a). Map in detail the extent and structure of the white tuff bed that is exposed in the lower Stimson quarry. It is an excellent strain marker that can be traced across the landscape and should record significant fault offset.

Additional Information

Identifiers

Type Scheme Key
DOI https://www.sciencebase.gov/vocab/category/item/identifier doi:10.5066/P9PVK0Q3

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