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The Peters Hills basin, a Neogene wedge-top basin on the Broad Pass thrust fault, south-central Alaska

August 9, 2018

The Neogene Peters Hills basin is a small terrestrial basin that formed along the south flank of the Alaska Range during a time in which there was regional shortening. The formation of the Peters Hills basin is consistent with it being a wedge-top basin that formed on top of the active southeast-vergent Broad Pass thrust fault. Movement along this thrust raised a ridge of Jurassic and Cretaceous metasedimentary rocks, which then trapped behind it Miocene and Pliocene sediments that were derived from the growing Alaska Range. The presence of this thrust fault is consistent with regional structural, stratigraphic, seismicity, gravity, and aeromagnetic data. The Peters Hills basin is no longer a depocenter, but if the Broad Pass thrust remains active, it would help explain the westward decrease in Quaternary slip rate along the Denali fault system, and it may constitute a seismic hazard that could produce earthquakes in the Mw 7.6–7.8 range.

Citation Information

Publication Year 2017
Title The Peters Hills basin, a Neogene wedge-top basin on the Broad Pass thrust fault, south-central Alaska
DOI 10.1130/GES01487.1
Authors Peter J. Haeussler, Richard W. Saltus, Richard G. Stanley, Natalia Ruppert, Kristen Lewis, Susan M. Karl, Adrian M. Bender
Publication Type Article
Publication Subtype Journal Article
Series Title Geosphere
Series Number
Index ID 70198901
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Geology Minerals