Faculty Advisor

Mike Valentine and Kenneth Clark

Area of Study

Science and Mathematics

Publication Date

Summer 2021


The most prominent geologic feature in the Olympic Peninsula is the Crescent Formation. The Crescent Formation (CF) is a massive unit of basalt up to 18 km thick which was accreted 52-48Ma. The Blue Mountain Unit (BMU) is a unit of continentally derived sediments which has previously been believed to be the sedimentary basement upon which the Crescent Formation (CF) was deposited ~50 Ma.(Fig.1) Recent research conducted by Prof. Ken Clark, Michael Eddy, Michael Polenz and multiple UPS grads found discontinuities which suggest that the BMU and CF are not part to the same coherent unit. Previous work suggests that a chemical and temporal discontinuity indicative of a major fault exists between the CF and the BMU. This study aimed to discover geophysical and geochemical evidence of this fault between the CF and BMU in the eastern Olympics. (Fig.1) This previously unidentified thrust fault is herein referred to as the Dusk Point Fault (DPF)


Geology Award


University of Puget Sound