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The Devil's Slide: South Fork Geology


The South Fork Valley Community Association presents a discussion featuring Western Washington University Master of Geology candidate Geoffrey Malick. The Devilís Slide: Catastrophic Landslides in the South Fork Valley. While pursuing his Masterís degree in geology at Western Washington University, Geoffrey Malick has undertaken a great deal of in-depth research pertaining to the Van Zandt Landslide Complex (Devilís slide), a bedrock landslide complex located here on the west side of the Van Zandt Dike in the foothills of the North Cascades. The formation has a legacy of multiple long-runout catastrophic landslides, two of which occurred approximately 1300 years before present and covered large portions of the South Fork Valley. Monitoring efforts from 2015 to 2018 provide evidence that slow incremental sliding continues deep within the slopes of the Van Zandt Dike. Although the movement is very slow, the large volume of material involved indicates the potential for future large catastrophic landslides. Light refreshments provided; audience questions encouraged. Everyone is welcome. Proceeds will support the maintenance and renovation of the historic Van Zandt Community Hall.